Screw Compressor Maintenance

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ARIEL Heavy Duty Oil Flooded Twin Screw Rotary Compressors TECHNICAL MANUAL For Models: AR166, AR208, AR260K & AR260 ARIEL CORPORATION 35 BLACKJACK ROAD, MOUNT VERNON, OHIO 43050 TELEPHONE: 740-397-0311 FAX: 740-397-3856 (For additional contact information, see PAGE 7 - 10) VISIT OUR WEB SITE: www.arielcorp.com REV: 3/02

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Ariel Flooded Screw Compressor Maintenance manual

Transcript of Screw Compressor Maintenance

Page 1: Screw Compressor Maintenance

ARIELHeavy Duty

Oil Flooded Twin ScrewRotary Compressors

TECHNICAL MANUALFor Models:

AR166, AR208, AR260K & AR260

ARIEL CORPORATION35 BLACKJACK ROAD, MOUNT VERNON, OHIO 43050

TELEPHONE: 740-397-0311 FAX: 740-397-3856(For additional contact information, see PAGE 7 - 10)

VISIT OUR WEB SITE: www.arielcorp.com

REV: 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260

CAUTIONGAS COMPRESSOR UNITS ARE COMPLICATED AND DANGEROUSPIECES OF EQUIPMENT. THOROUGH TRAINING ANDFAMILIARIZATION WITH THE EQUIPMENT IS REQUIRED.BEFORE STARTING THIS UNIT:FAMILIARIZE YOURSELF WITH THE UNIT.READ AND STUDY START-UP AND SHUT-DOWN INFORMATION FORBOTH PACKAGE AND COMPRESSOR CAREFULLY!A GAS/AIR MIXTURE UNDER PRESSURE CAN EXPLODE! YOU CANBE SEVERELY INJURED OR KILLED. MAKE SURE THECOMPRESSOR IS SUFFICIENTLY PURGED OF ANY EXPLOSIVEMIXTURE BEFORE LOADING.AFTER COMPLETING THE ABOVE, BEGIN PROPER STARTINGPROCEDURE.

CAUTIONDO NOT ATTEMPT TO START-UP UNIT WITHOUT REFER-RING TO THIS MANUAL SECTION 3: START-UP. IT IS ALSOESSENTIAL TO REFER TO THE PACKAGER’S OPERATINGMANUAL.

CAUTIONTHIS MANUAL EDITION IS BASED ON THE CURRENTDESIGN, BUILD AND PRACTICES. THIS MANUAL MAY NOTBE APPLICABLE TO EQUIPMENT BUILT PRIOR TO THEDATE ON FRONT COVER AND IS SUBJECT TO CHANGEWITHOUT NOTICE. CONTACT ARIEL WITH ANY QUESTIONS,SEE PAGE 7 - 10.

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TABLE OF CONTENTS

Design Specifications & Data .............................................................. 1-1

General ................................................................................................................... 1-1Operating Theory .................................................................................................... 1-3Specifications ......................................................................................................... 1-5 ................................................................................................................................ 1-5Product Information and Safety Plates ................................................................... 1-8

Important Safety Information ............................................................................. 1-9Fastener Tightening Torque ................................................................................. 1-10

Tightening Torque Procedures ........................................................................ 1-11Ariel Bolting .......................................................................................................... 1-12Alarm & Shutdown (also see Section 4) ............................................................... 1-13

Gas Discharge High Temperature Settings .................................................... 1-13Storage and Transportation of Compressor ......................................................... 1-13

Installation ............................................................................................. 2-1

General ................................................................................................................... 2-1Procedure For Setting and Aligning ........................................................................ 2-1

Setting ............................................................................................................... 2-1Alignment .......................................................................................................... 2-1

Vents and Drains .................................................................................................... 2-2Inlet Gas Debris Screens ........................................................................................ 2-3Inlet Gas Liquids ..................................................................................................... 2-3

Start Up .................................................................................................. 3-1

General ................................................................................................................... 3-1Start Up Check List ................................................................................................. 3-2Maximum Allowable Working Pressure .................................................................. 3-7Relief Valve Settings .............................................................................................. 3-7Filling and Priming an Oil Lube Oil System - Before Starting ................................. 3-7

Filling The System ............................................................................................. 3-7Slide Valve Positioning - Hydraulic ......................................................................... 3-8

Theory of Operation .......................................................................................... 3-8Visual Position Indicator (Yellow Pointer), Internally Changeable Models ........ 3-9Visual Position Indicator (Yellow Pointer), Externally Changeable Models ....... 3-9Slide Valve Positioning at Start-up .................................................................. 3-10

Slide Valve Positioning - Hand Wheel .................................................................. 3-10Theory of Operation ........................................................................................ 3-11Slide Valve Positioning at Start-up .................................................................. 3-12Balance Oil Connection ................................................................................... 3-12

Built In Volume Ratio Changes - Internally Changeable Vi .................................. 3-13Built In Volume Ratio Changes - Externally Changeable Vi ................................. 3-14Thrust Balance System ........................................................................................ 3-14

Thrust Balance Pressure Adjustment .............................................................. 3-14

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Gas/Oil Separator Coalescing Filter - Scavenged Oil Line Flow Adjustment .......3-15Sour Gas Service with over 100 ppm to 2% H2S or Other Dangerous Gases .....3-15Compressor Re-Application ..................................................................................3-16

Oil System, Lubrication & Venting ...................................................... 4-1

General ...................................................................................................................4-1Lubricants ...............................................................................................................4-2

Petroleum Based Oils - also referred to as mineral oils: ...................................4-5Synthetic Lubricants ..........................................................................................4-5

Auxiliary Equipment ................................................................................................4-6Lube Oil Strainer ................................................................................................4-6Oil Cooler ...........................................................................................................4-6Temperature Control Valve ...............................................................................4-6Cold Ambient Temperatures ..............................................................................4-6Prelube Pump ....................................................................................................4-7Oil Pressure Regulating Valves .........................................................................4-7Oil Filters ...........................................................................................................4-7Liquids and Contaminants in Gas ......................................................................4-8

Compressor Oil Pump .............................................................................................4-8Compressor Oil Supply Pressure Calculations .......................................................4-9Gas Balance Line Pressure (GBLP) Calculation ..................................................4-10Compressor Re-Application ..................................................................................4-10Warranty ...............................................................................................................4-10Lube Oil Shutdowns ..............................................................................................4-10

Pressure: .........................................................................................................4-11Temperature: ...................................................................................................4-12

Rotor Injection Flow ..............................................................................................4-12Flushing Requirements .........................................................................................4-12

Maintenance .......................................................................................... 5-1

General Introduction ...............................................................................................5-1Mechanical Seal ......................................................................................................5-2

Replacing the Mechanical Seal .........................................................................5-3Optional Collared Retaining Bolts ......................................................................5-4

Slide Valve Replacement - Internally Changeable Vi .............................................5-6Compressors with Individual Cover Plates ........................................................5-7Replacement .....................................................................................................5-7Slide Valve Cylinder Reassembly Into Compressor ..........................................5-7

Slide Valve Axial Position Indicator Transducer .....................................................5-8Externally Changeable Slide Valve .......................................................................5-10

Slide Valve Volume Ratio (Vi) Change - Externally Changeable Vi ................5-10 Vi Spacer Adjustments - Externally Changeable Vi .............................................5-12Slide Valve Inspection/Replacement - Externally Changeable Vi .........................5-12

Removal ..........................................................................................................5-12Replacement ...................................................................................................5-13Slide Valve Cylinder Assembly Into Compressor ............................................5-13

Oil Pump and Geared Tooth Coupling ..................................................................5-14

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Oil Pump Replacement ................................................................................... 5-14Coupling Replacement .................................................................................... 5-15

Ethylene Glycol Contamination ............................................................................ 5-16Mineral Deposit Build-Up in Low Pressure Natural Gas Applications .................. 5-16

Technical Assistance ........................................................................... 6-1

Recommended Maintenance Intervals ................................................................... 6-1Daily .................................................................................................................. 6-1Monthly (in addition to Daily Requirements) ..................................................... 6-2Every 6 Months or 4,000 Hours (plus Daily/Monthly) ........................................ 6-2Yearly or every 8,000 Hours (plus Daily/Monthly/6 Months) ............................. 6-2

Trouble Shooting .................................................................................................... 6-2

Appendices ............................................................................................ 7-1

Ariel Tools ............................................................................................................... 7-1Ariel Furnished Tools ........................................................................................ 7-1

Minimum Hand Tools Required .............................................................................. 7-3Terms, Abbreviations and Conversion to SI Metric ................................................ 7-4

Area ................................................................................................................... 7-4Flow - Gas ......................................................................................................... 7-4Flow - Liquid ...................................................................................................... 7-4Force ................................................................................................................. 7-4Heat ................................................................................................................... 7-4Length ............................................................................................................... 7-4Mass .................................................................................................................. 7-4Moment or Torque ............................................................................................. 7-5Power ................................................................................................................ 7-5Pressure or Stress ............................................................................................ 7-5Speed ................................................................................................................ 7-5Temperature ...................................................................................................... 7-5Time .................................................................................................................. 7-5Viscosity ............................................................................................................ 7-6Volume .............................................................................................................. 7-6Other Abbreviations .......................................................................................... 7-6

Gas Analysis Common Abbreviations .................................................................... 7-8Metric Factors ......................................................................................................... 7-9Technical and Service Schools on Ariel Compressors ........................................... 7-9Ariel Customer Technical Bulletins (Formerly Ariel Newsletters) ........................... 7-9Vendor Literature .................................................................................................... 7-9Ariel Contact Information ...................................................................................... 7-10

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SECTION 1 - DESIGN SPECIFICATIONS & DATA

General

Ariel compressors are designed for ease of operation and maintenance. Experience has shown that an Ariel compressor will normally provide years of satisfactory performance with minimal proper maintenance.

While Ariel rotary compressors share many similarities, each model has aspects that are unique to the particular model type. If you, as an operator, are familiar with Ariel reciprocat-ing compressors, it is still important to review this rotary manual to determine the differ-ences. If you are new to Ariel rotary compressors, it is critical that you become very familiar with this manual prior to operating the compressor. Rotary compressors are precision rotat-ing equipment, requiring knowledgeable operation and maintenance.

Ariel rotary compressors feature positive displacement, single stage operation using oil-flooded twin screw rotors. The compressors are designed primarily for natural gas but have applications for other gases, such as propane. Heavy duty babbitted journal bearings, anti-friction rolling element thrust bearings, and a variable capacity, field changeable volume ratio (Vi) allow rotary compressors to operate in a wide variety of gas applications. Internally or externally changeable volume ratio (Vi) slide valves are available.

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FIGURE 1-1: SIDE VIEW - ARIEL ROTARY COMPRESSOR WITH INTEGRAL OIL PUMP - TYPICAL

Vi

Vs

Vd------=

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Rotary compressors have few moving parts, can run at high speeds, can accommodate a wide range of compression ratios and operate with minimum pressure pulsations. They are generally applied in low suction pressure applications, discharging into medium pressure lines. To maintain high compression efficiency, care should be taken to operate the com-pressors as close to the installed slide valve volume ratio (Vi) as possible.

Oil is the lifeblood of rotary screw compressors. Catastrophic damage can occur to rotors, bearings and mechanical seal without adequate oil quality, volume and viscosity. Oil selec-tion is based on process gas composition, operating temperatures and pressures. If gas composition or operating conditions change, lubrication selection, gas/oil separator operat-ing temperature and counter thrust balance pressure must be re-evaluated.

During compressor operation, process gas will dilute the oil, reducing viscosity. Liquid and solid contaminants in the suction gas stream must be effectively removed to minimize the detrimental affects on the compressor and its oil system. Pressurized oil viscosity should never be allowed to drop below the minimum requirement. Ariel rotary screw compressors are designed for oil flooding of the compression chamber, with oil separation and recircula-tion, at minimal oil loss. Packager design and oil selection determines the amount of oil car-ryover (loss) downstream of the gas/oil separator.

This manual is designed to provide information on installation, start up, operation, mainte-nance and trouble shooting of an AR166, AR208, AR260 or AR260K compressor. If you have any questions please contact your packager. If they are unable to provide resolution, they will refer your questions to Ariel Corporation. If you prefer, you may always contact Ariel directly (refer to “Ariel Contact Information” on page 7-10).

This manual provides design specifications for standard current production equipment at publication date. Do not exceed information plates ratings for a particular compressor.

FIGURE 1-2: MALE/FEMALE ROTOR PAIR (5/7 LOBE/FLUTE RATIO)

Lobe

Flute

Male (Drive) Rotor

Female (Driven) Rotor

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The data shown on the Information Plates is very important when communicating questions concerning an Ariel compressor. (Refer to Figure 1-3: on page 1-3)

NOTE: USE SERIAL NUMBERS IN ALL CORRESPONDENCE.

NOTE: THE CURRENT DESIGN OF THE ARIEL ROTARY COMPRESSORS FEATURES AN INTEGRAL OIL PUMP, MULTIPLE END COVERS, ANSI FLANGES AND INCH NPT EXTERNAL CONNECTIONS.

NOTE: INTERNALLY CHANGEABLE Vi MODELS REQUIRE CHANGE OUT OF THE SLIDE VALVE TO CHANGE THE Vi OF THE UNIT. EXTERNALLY CHANGEABLE Vi MODELS REQUIRE CHANGE OUT OF A SPACER ONLY.

NOTE: THE ROTARY COMPRESSORS OFFER TWO OPTIONS FOR LOADING AND UNLOADING: HYDRAULIC AND HANDWHEEL.

The various rotary compressor configurations are shown in Figure 1-4:, Figure 1-5: and Fig-ure 1-6:.

Operating Theory

The rotary compressor’s oil-flooded, twin screw design consists of a male rotor which directly drives the female rotor. The male rotor lobes drive the female rotor flutes, as in a “spiral gear” motion. The male rotor is driven by a prime mover (engine or motor), which can be a direct drive or thru a speed increasing gear set. The female rotor is driven at a lesser speed; 5/7 times male rotor speed. Rotor tip speeds are generally between 49 to 164 feet/second (15 to 50 m/s).

The rotor length, diameter, lobe/flute and speed design determines compressor full load capacity. The selected slide valve determines internal compression ratio. Slide valve axial positioning control provides variable partial load capacities. Several slide valve/volume ratio (Vi) choices are available for each compressor model. Depending upon the option chosen, the volume ratio (Vi) is field internally-changeable by changing the slide valve or field exter-nally-changeable using spacers provided with the unit.

FIGURE 1-3: AUXILIARY END VIEW SHOWING TYPICAL INFORMATION PLATE LOCATION

InformationPlate

Multiple End Covers - ‘N’ Version

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The internally changeable method requires changeout of the slide valve (refer to Figure 1-5: on page 1-6) and the externally changeable method requires changeout of a spacer only (refer to Figure 1-4: on page 1-6 and Figure 1-6: on page 1-7).

As the compressor’s twin rotors un-mesh, at the top, the flutes and lobe voids are exposed to the suction gas stream and fill with gas. As the rotors turn out, the flutes and lobe voids are closed and sealed by the rotor housing, creating spiral segmental compression cham-bers which move gas axially toward discharge. Oil is injected into the compression cham-bers after they close off from the suction pressure, to provide sealing, cooling and lubrication. Rotor meshing, at the bottom, progressively reduces compression chambers vol-umes axially, to compress the gas/oil mixture. Rotor rotation exposes the compression chambers to the (radial/axial) discharge port, moving the compressed gas/oil mixture out of the compressor.

Discharge piping carries the compressed gas/oil mixture to a coalescing filter-separator where the oil is separated from the process gas. The oil is piped to a cooler and re-circulated to the compressor. Refer to Figure 4-1: on page 4-3 or Figure 4-2: on page 4-4.

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 1 - DESIGN SPECIFICATIONS & DATA

T

Specifications

ABLE 1-1: BASIC SPECIFICATIONS

MODEL AR166 AR208 AR260K AR260

Male Rotor Diameter, in. (mm) 6.54 (166) 8.19 (208) 10.24 (260)

Number of Male Rotor Lobes 5

Number of Female Rotor Flutes 7

L/D Ratio 1.6 1.2 1.6

Operating Speed, RPM 1148 To 5739 918 To 4591 735 To 3673

Inlet Volume, CFM (m3/h) To 600 (1019) To 950 (1614) To 1080 (1835)

To 1450 (2464)

Horsepower (kW) To 530 (394) To 820 (612) To 950 (708) To 1270 (947)

Suction Pressure, psig (barg) To 115 (7.93)

Discharge Pressure, psig (barg) To 362 (25.00)

Maximum Discharge Temperature 248°F (120°C)

Height - Mounting Feet to Rotors 6, in. (mm) 8.661 (220) 10.827 (275) 13.386 (340)

Maximum Width, in. (m) 19.7 (0.5) 23.6 (0.6) 28.3 (0.72)

Maximum Length, in. (m) 41.9 (1.1) 50.1 (1.3) 55 (1.4) 59 (1.5)

Approximate Weight without Oil Pump, lb. (kg) 1050 (470) 1800 (820) 3100 (1400) 3300 (1500)

Slide Valve Optionsa - Volume Ratio, Vi

a. 2.0 Vi minimum, internally changeable slide valve only; 2.2 Vi minimum, externally changeable slide valve only.

2.0, 2.2, 2.6, 3.5, 4.8

Oil Filter - Bearing, Seal & Control Cylinder, nominal 3 - 7 micron @ 98.7% Efficiency

Oil Filter - Rotor Injection, nominal 15 - 16 micron @ 98.7% Efficiency

Recommended Oil Retention in Gas/Oil Separatorb

b. Recommended time depends on separator design.

2 minutes

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FIGURE 1-4: TYPICAL SIDE VIEW CROSS-SECTION ANSI (HYDRAULICALLY CONTROLLED, EXTER-NALLY CHANGEABLE [SPACER] Vi)

FIGURE 1-5: TYPICAL SIDE VIEW CROSS-SECTION ANSI (HYDRAULICALLY CONTROLLED, INTER-NALLY CHANGEABLE [SLIDE VALVE] Vi)

Suction

Discharge

Rotor

Slide Valve

Internal By Pass

Mechanical SealHydraulic

Control Piston

Slide Valve Position Indicator

Vi Spacer

Suction

Discharge

Rotor

Slide ValveInternal By Pass

Mechanical SealHydraulic

Control Piston

Slide Valve Position Indicator

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FIGURE 1-6: TYPICAL SIDE VIEW CROSS-SECTION ANSI (HAND WHEEL CONTROLLED, EXTERNALLY CHANGEABLE [SPACER] Vi)

Table 1-2: HAND WHEEL TURNS VS. SLIDE VALVE TRAVEL (20a TO 100% AXIAL POSITION)

a. 20% position is against stop.

SLIDEVALVEb

Vi

b. This table applies for externally changeable slide valves only.

AR166 AR208 AR260K AR260

NO. OFTURNS

TRAVELIN. (cm)

NO. OFTURNS

TRAVELIN. (cm)

NO. OFTURNS

TRAVELIN. (cm)

NO. OFTURNS

TRAVELIN. (cm)

4.8 25 2.5 (6.4) 34 3.4 (8.6) 44 4.4 (11.2) 39 3.9 (9.9)

3.5 33 3.3 (8.4) 44 4.4 (11.2) 53 5.3 (13.5) 52 5.2 (13.2)

2.6 43 4.3 (11.0) 56 5.2 (13.2) 65 6.5 (16.5) 68 6.8 (17.3)

2.2 50 5.0 (12.7) 66 5.3 (13.5) 74 7.4 (18.8) 78 7.8 (19.8)

Hand Wheel

Suction

Rotor

Mechanical Seal

DischargeSlide ValveInternal BypassVi Spacer

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Product Information and Safety Plates

FIGURE 1-7: PRODUCT INFORMATION AND SAFETY - TYPICAL ARIEL ROTARY COMPRESSOR WITH HAND WHEEL

DRIVE END VIEWSIDE VIEW

Unit Information plate: Ariel Corporation address, Model number, Serial number, Maximum Rated Speed, Maximum Suc-tion Pressure, Maximum Discharge Pres-sure, original furnished Oil Pump Model and Ariel shipping date. Safety Informa-tion. Inspectors tag.

Use suction flange tapped holes to install two (2) eye-bolts (furnished in tool box) for lifting compressor sepa-rately

Engine/Motor

Direction of Rotation arrow, located at the drive end

TOP VEIW

AUXILARY END VIEW

Volume Ratio (Vi) Plate

Currently Installed Slide Valve - Change/Date

Compressor Serial Number, MAWP, Hydrostatic Test Pressure, Test Date, Model Number and Tester’s Per-sonal Stamp are stamped on rotor housing

Center of Gravity (Compressor Only)

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Important Safety Information

CAUTIONSEVERE PERSONAL INJURY AND PROPERTY DAMAGECAN RESULT IF PRESSURE SYSTEM IS NOTCOMPLETELY VENTED BEFORE LOOSENING THE BOLTSON FLANGES OR FITTINGS TO PRESSURE CONTAININGAREAS. CONSULT ARIEL TECHNICAL MANUAL BEFOREPERFORMING ANY MAINTENANCE.

CAUTIONNOISE GENERATED BY COMPRESSION MACHINERYCAN BE A SOURCE FOR HEARING INJURY. SEEPACKAGER’S INFORMATION FOR ANY SPECIFICRECOMMENDATIONS. WEAR HEARING PROTECTIONWHEN UNIT IS RUNNING.

CAUTIONHOT GAS TEMPERATURES, ESPECIALLY THE GASDISCHARGE AREAS, HOT OIL AND HIGH FRICTIONAREAS CAN BE A SOURCE FOR BURNS. WEAR PROPERINSULATION WHEN WORKING AROUND THESE AREAS.SHUT DOWN UNIT AND ALLOW TO COOL BEFOREDOING MAINTENANCE IN THESE AREAS.

CAUTIONSURFACES MAY BE HOT AND CAN BE A SOURCE FORBURNS. WEAR PROPER INSULATION WHEN WORKINGAROUND THESE AREAS.

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Fastener Tightening Torque

Listed in the following tables are fastener tightening torque values, required for proper assembly of an Ariel AR166, AR208 AR260K or AR260 compressor. Refer to the section concerning a subject component for detailed assembly procedures.

Threads are to be clean and free of burrs.

Torque values are based on the use of petroleum type lubricants on both the threads and seating surfaces. Use lubricating oil or Lubriplate 630 on threads and seating surfaces, except where Loctite is specified. Molybdenum disulfide lubricants and Never-Seez are not to be used for fastener lubrication, unless specified, or excessive stresses can result with the listed values.

TABLE 1-3: CAPSCREW (OR STUD-NUT) TIGHTENING TORQUE VALUES

NOMINAL SIZE XTHREAD PITCH

CLASS 8.8 OR 12.9 CAP SCREWa

(OR STUD-NUT)

a. If applying this table to coupling retaining bolts, consult packager’s information for proper torque values, based on unit rating. Table values will provide bolting torque for maximum power transmission rating of compressor.

SEATING DOG POINT STUDS

LB-FT (N·m) LB-FT (N·m)

M6 x 1 5 (60 LB-IN) (7) 2 (24 LB-IN) (3)

M8 x 1.25 13 (156 LB-IN) (18) 5 (60 LB-IN) (7)

M10 x 1.5 25 (35) 11 (132 LB-IN) (15)

M12 x1.75 45 (60) 19 (26)

M16 x 2 115 (155) 48 (65)

M20 x 2.5 225 (305) 93 (125)

M24 x 3 385 (525) 160 (220)

M27 x 3 570 (775) 240 (325)

M30 x 3.5 775 (1050) 320 (435)

M42 x 4.5 2170 (2950) 905 (1230)

TABLE 1-4: OTHER FASTENERS - TIGHTENING TORQUE VALUES

APPLICATION NOMINAL SIZE XTHREAD PITCH LB-FT (N·m)

Mechanical Seal Locknut M60 x 2 60 (81)

M75 x 2 110 (149)

M90 x 2 160 (217)

M130 x 2 275 (373)

Slide Valve - Nut M16 x 2 40 (54)

M20 x 1.5 85 (115)

Slide Valve Position Indicator - Mounting & Cover Screws

M5 x 0.8 1 (12 LB-IN) (1.4)

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Tightening Torque ProceduresListed below are some procedures which make fastener tightening more accurate and will help assure that the proper torque is being applied.

1. Assure that the torque wrench is properly calibrated and used by qualified person-nel to achieve the required fastener tightening torque for all critical parts.

2. Always check to determine over what range the torque wrench is accurate, since most torque wrenches are not accurate over their entire range.

3. Tighten critical multi-bolt assemblies in steps. Tighten each bolt until snug using a criss-cross pattern. Next, tighten each bolt to 25% of full torque, moving across from bolt to bolt, in a criss-cross pattern. Repeat this step for 50%, 75%, and 100% of full torque.

4. Always apply a steady slow force to a torque wrench, do not jerk it. When a torque wrench is jerked the amount of torque applied can be as much as one and a half times the amount set on the wrench. For example, if a wrench is set at 80 lb x ft (108 N·m) but is jerked, 120 lb x ft (163 N·m) torque can be applied.

5. Always do the final tightening with a torque wrench. Do not tighten the fastener with a ratchet or impact wrench and then "check" the torque with a torque wrench.

6. Do not double tap a torque wrench. Rapidly double tapping a torque wrench will make the torque on the bolt more than what is set by a significant amount. If it is desired to check the setting release all pressure on the wrench and then slowly apply a steady force until the click is felt.

7. Always reset the torque wrench to its lowest setting when the job is complete. If the torque wrench is left in a high setting the spring in it is stressed and will become inaccurate with time. If the torque wrench is put back to its lowest setting the spring will relax and retain its accuracy.

8. Do not use a torque wrench to break fasteners loose as it may overload the torque wrench and/or cause loss of calibration.

9. For applications requiring the use of a boxed end or crowsfoot type adapter with a torque wrench to reach not readily accessible fasteners, the torque wrench setting will not be the actual torque applied to the fastener.1

10. The ratio of actual torque at the fastener with that on the wrench scale is a function of the adapter's length and its position in relation to the torque wrench beam and the location on that at which the force is applied (see Figure 1-8:).

Slide Valve Piston/Rod Nut M40 x 1.5 140 (190)

M85 x 2 185 (251)

1. The exception is when the adapter is 90° to the torque wrench. The torque will be the same as on the wrench scale (see Figure 1-9:).

TABLE 1-4: OTHER FASTENERS - TIGHTENING TORQUE VALUES

APPLICATIONNOMINAL SIZE XTHREAD PITCH LB-FT (N·m)

Tw TaL

L A+-------------

=

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Tw = Torque wrench setting, lb x ft or N·m

Ta = Torque required at fastener, lb x ft or N·m

L = Length of wrench, ft or m (from square drive end to center point of force on handle)

A = Length of adapter, ft or m (measured through end of adapter on a line par-allel to the center line of the wrench)

These are general guidelines to assist in the proper use of torque wrenches. Consult with your torque wrench dealer for more detailed information.

Ariel Bolting

Bolts have been selected that meet Ariel's strength, elongation, sealing and locking require-ments. Proper bolting must be used and tightened to the values listed in Table 1-3 and Fig-ure 1-4 on page 1-10.

Figure 1-10: is provided to assist in the identification of bolts used in an Ariel compressor.

FIGURE 1-8: TORQUE WRENCH WITH ADAPTOR AT ANY ANGLE

FIGURE 1-9: TORQUE WRENCH WITH ADAPTOR AT RIGHT ANGLE

FORCE

FORCE

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Alarm & Shutdown (also see Section 4)

Gas Discharge High Temperature SettingsA gas discharge high temperature shutdown is required. Set within 10% of normal operating temperature, to a maximum of 238°F (114°C) alarm and 248°F (120°C) shutdown. High tem-perature limits are based on rotating clearance requirements.

NOTE: EXCEEDING THE HIGH TEMPERATURE SHUTDOWN LIMITATION WILL RESULT IN CATASTROPHIC EQUIPMENT FAILURE.

Storage and Transportation of Compressor

Protect compressor to prevent corrosion and seal to prevent exchange of atmosphere, when inactive, in storage or when transporting. Consult Ariel for instructions to protect and seal compressor to ER-25-1.

When transporting the packaged skid, remove the center section of the drive coupling.

FIGURE 1-10: METRIC BOLT IDENTIFICATION - HEX SOCKET HEAD & 12 POINT, CLASS 8.8 OR 12.9

CAUTIONWHEN RE-ASSEMBLING OR REPLACING BOLTING, SEETHE PARTS LIST TO DETERMINE THE PROPERFASTENER GRADE AND PART NUMBER. ALL SPECIALFASTENERS MUST BE REPLACED WITH ARIEL PARTS.

12.9

8.8

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NOTES

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260

SECTION 2 - INSTALLATION

General

Compressor installation with the associated driver and piping, is to be done with care and precision. This section does not attempt to address all of the concerns that can arise during installation, but addresses many of the primary considerations.

Procedure For Setting and Aligning

The following points deserve special attention during the setting and alignment of the com-pressor:

1. Be sure that driver will rotate compressor rotor drive shaft in proper direction, prior to start-up. See Figure 1-7: on page 1-8, drive end view for rotation arrow.

NOTE: THE COMPRESSOR DRIVE SHAFT ROTATES CLOCKWISE WHEN OBSERVER IS FACINIG THE COMPRESSOR DRIVE SHAFT END. ANY REVERSE ROTA-TION CAN RESULT IN SERIOUS DAMAGE TO THE COMPRESSOR.

2. The skid design should:Transmit compressor and driver reaction forces to the foundation.Assure that there is a sufficient mismatch between the shaking forces and the natural frequency of the skid.Have sufficient stiffness and strength so that the compressor can be mounted flat with no bending or twisting of the compressor casing, and so that proper compressor coupling alignment can be attained and maintained. This can be accomplished by shims or careful grouting.

SettingThe following procedure is to be used for setting the compressor on the skid:

After finding the approximate position of the compressor frame, the mounting bolts are to be tightened in place and then loosened. Shims are then to be adjusted so there is no move-ment more than a variation of 0.002 inches (0.05 mm) between the bottom of the feet and the skid supports. Consult Packager’s information for mounting bolt tightening torque val-ues. This work must be performed prior to the addition of piping.

AlignmentProper alignment is necessary for satisfactory performance. A flexible coupling will not make up for poor alignment. Misalignment can result in:

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 2 - INSTALLATION

• High bending moment on the compressor drive shaft• Large axial forces which reduce thrust bearing life• Excessive wear to the bearings• And if severe, probable damage to various components

An Ariel compressor may be aligned by any of a number of acceptable methods such as:

• Face/peripheral• Reverse indicator• Across the disc pack• Optical• Laser• Mechanical direct to computer

When aligning a unit some procedural concerns are:

• Soft foot (compressor and driver are not laying flat)• Repeatable readings• Which way indicator moves (plus or minus)• Thermal growth• Piping stresses• Indicator sag

When properly aligned the forces on the connected equipment will be at a minimum. This will result in long bearing life and a smooth running unit. Consult Packager’s information for alignment procedure.

Vents and Drains1

It is critical, for the safe operation of the compressor, to assure that all vents and drains are open, functional and, if necessary, tubed off of the skid or out of the building. Depending upon your climate and insect population it can be necessary to install screens over the vents and drains to assure that they do not become blocked. This can be essential if the compres-sor is shutdown for a long period of time.

Some other points are:

1. A vent should be provided to safely relieve pressure from the system.2. Adequate vents and drains are to be provided for mechanical seal weepage and

rotor housing oil drainage. All vents and drains must be installed in such a man-ner as to prevent the collection of liquids that could cause the build up of either gas or liquid. When a gas heavier than air is involved, vent and drain design must be accommodating.

3. Do not block view of mechanical seal weepage tube, as oil leakage rate is a visual indication of seal condition.

1. Also see Section 4.

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Inlet Gas Debris Screens

Foreign matter in the gas stream can effect compressor wear and lubrication. Inlet gas debris start-up screens with a maximum 75 micron (0.003 in.) openings are recommended to be installed upstream of the compressor suction flange. These screens should be moni-tored by differential pressure and cleaned or replaced before differential pressure approaches the collapse pressure of the screen.

Inlet Gas Liquids

Liquid water and gas condensates in the process gas stream have detrimental affects on oil system gas/oil separator operating temperature and oil viscosity. Liquid slugging that can adversely affect the compressors’s mechanical operation and oil system must be effectively removed or compressor damage will occur.

NOTE: SOLID AND LIQUID CONTAMINANTS IN THE PROCESS GAS SYSTEM MUST BE EFFECTIVELY REMOVED UPSTREAM OF THE COMPRESSOR.

NOTE: FREE LIQUIDS THAT ARE NOT REMOVED CAN BE PARTICULARLY TROU-BLESOME IN LOW PRESSURE NATURAL GAS SERVICE APPLICATIONS. MINERAL DEPOSITS (SALT AND CALCIUM) CAN BUILD UP ON THE SUCTION STRAINER SCREEN AND IN THE COMPRESSOR DUE TO DISSOLVED MINER-ALS IN WATER SATURATED PROCESS GAS. THESE MINERALS PLATE OUT WHEN WATER FLASHES OFF DUE TO PRESSURE DROP OR HEAT.

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NOTES

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260

SECTION 3 - START UP

General

To ensure a smooth start up, it is important that the items in the Start Up Check List, pro-vided in this section, be positively satisfied. It is also important that the operator understand how to operate the compressor in a safe and efficient manner, prior to start up.

CAUTIONBEFORE STARTING A NEW COMPRESSOR, OR AFTER RE-LOCATING OR RE-APPLYING A COMPRESSOR, OR AFTERMAJOR OVERHAUL, BE SURE TO COMPLETE AND CHECKOFF ALL THE ITEMS ON THE START UP CHECK LISTSHOWN IN THIS SECTION. THIS LIST IS DESIGNED TO HELPASSURE SAFETY IN STARTING AND OPERATING THE COM-PRESSOR.

CAUTIONFOR SAFE OPERATION, DO NOT ATTEMPT TO START-UPTHE UNIT WITHOUT BEING COMPLETELY KNOWLEGABLEOF THE INFORMATION CONTAINED IN THIS SECTION. IT ISALSO ESSENTIAL TO REFER TO THE PACKAGER’S OPER-ATING MANUAL.

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Start Up Check List

Compressor Model AR-__________ Serial No. R-___________ Slide Valve Vi ________

Slide Valve Control Activation: Hydraulic_____ Hand Wheel_____Driver Manufacturer____________________Model _____________________________Driver Rated Speed_____________________Speed Increasing Gear Ratio Packager____________________________Packager Unit No.____________________Date Packager Shipped________________Serviceman_________________________Customer____________________________Start Up Date________________________Location____________________________Field Contact________________________Field Telephone No.___________________Unit Location________________________Gas Service_______________________________Compressor Oil - Make/Grade______________________________________________

Check List - Prior To Starting YES NO

1. Are the correct Ariel parts book, technical manual, special tools, Vi shims (externally changeable) and spares available? _____ _____

2. Have the design limitations for the compressor model such as MAWP, maximum suction & discharge pressures, maximum & minimum speed, discharge temperature been checked? _____ _____

3. Have the Packager’s design operating conditions been reviewed? _____ _____Pressure, PSIG (kPa): Suction _________ Discharge_________Temperature, °F (°C): Suction _________ Discharge_________Maximum RPM__________ Minimum RPM___________Current Gas Analysis Reviewed__________ SG__________If start-up conditions are different, check with Packager or Ariel.

4. Soft Foot Check [max. allowable 0.002” (0.05 mm)]: Have the compressor feet supports been shimmed so the machine is not twisted or bent? _____ _____

5. Have compressor anchor bolts been re-torqued? _____ _____6. Have the piping and supports been checked to be sure they do

not bend or stress compressor? _____ _____7. Have coupling bolt torque values been rechecked? _____ _____8. Has the compressor to driver alignment been checked? _____ _____

See compressor outline drawing for shaft thermal growth value.9. Record coupling dial indicator readings in inches (mm) at the

3, 6, 9 & 12 o’clock positions on lines provided:

Face Rim

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Compressor Model AR-__________ Serial No. R-___________ Slide Valve Vi ________

Check List - Prior To Starting YES NO

10. Does the compressor rotor turn freely? _____ ______

NOTE: ROTARY COMPRESSOR THRUST BEARING PRELOAD PRODUCES A NOR-MAL “ZERO” AXIAL THRUST. EXCESSIVE STUBSHAFT AXIAL FORCE, PUSHING OR PULLING, WILL RESULT IN BEARING DAMAGE.

11. Has coupling center section been re-installed and has coupling been inspected for excessive axial distortion forces, pushing or pulling? _____ ______

12. Has preservation oil been drained from rotor housing? _____ ______13. Have oil & gas systems been pressurized & leak tested? _____ ______14. Has proper oil been installed that matches operating conditions

with a viscosity adequate for current gas analysis? _____ ______15. Has oil supplier provided gas dilution versus predicted oil

viscosity information? _____ ______16. Has the compressor oil system been filled with oil to the proper

level without over filling? _____ ______17. Is the compressor oil supply isolation valve open? _____ ______

NOTE: CLEARLY LABEL UNIT WITH COMPRESSOR OIL MAKE/GRADE CURRENTLY IN USE.

18. Does the compressor oil system low level shutdown work? _____ ______19. Have the properly rated gas inlet separator, oil filters and strainers,

and separator coalescing elements been installed? _____ ______20. Are the oil filter elements and all oil piping primed with oil? _____ ______21. Is the low oil differential pressure shutdown installed and tubed

correctly to the bearing oil supply and scavenger oil gallery? _____ ______22. Is the low oil differential pressure shutdown set & does it work? _____ ______23. Is there an oil cooler? Note: Recommended compressor inlet oil

temperature is 150°F (66°C). _____ ______24. Is the rotor injection oil temperature control valve setting appropriate for

start-up conditions? _____ ______25. Is the oil temperature control valve piped for a “mixing” condition? _____ ______26. If so equipped, is there a working vibration shutdown mounted on

the compressor or drive train? _____ ______27. Is there some method of suction pressure control upstream of the

compressor? (Maximum suction pressure = 115 psig) _____ ______28. Are the suction and discharge pressure shutdowns set and

working? _____ ______29. Are the safety relief valves installed and working to protect

compressor gas and oil piping systems? _____ ______

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 3 - START UP

Compressor Model AR-__________ Serial No. R-___________ Slide Valve Vi ________

Check List - Prior To Starting YES NO

30. Is the gas high discharge temperature shutdown installed, setat 10% above anticipated temperature & working? _____ _____

31. Is the mechanical seal leakage tubing installed, unpluggedand visible to determine if leakage occurs? _____ _____

32. Have the gas suction lines been blown out to remove water, slag, dirt, etc.? _____ _____

33. Has strainer screen been installed upstream of compressor suction? _____ _____

34. Were the compressor bearings and mechanical seal prelubed prior to starting? Note: A prelube pump is required. _____ _____

35. Does the driver rotation match the compressor rotation arrow? _____ _____36. For engine driven units, has the machine been rolled to make

sure it is free? _____ _____37. For other drivers, has the machine been barred over by hand to

ensure it is rolling free? _____ _____38. For machines compressing a combustible gas, has the piping

and compressor been purged to remove all air? _____ _____39. Have start-up instructions for other package equipment been

followed? _____ _____40. Has compressor slide valve (internally changeable) been moved to 0%

(unloaded) axial position, then hydraulic pressure released to verify spring will move slide valve to about 20% axial (part load) position? _____ _____

41. Has the compressor slide valve been moved back to zero percent orminimum load position, to allow compressor to start-up unloaded? _____ _____

42. Have bearing, mechanical seal and gas balance line operating pressures been determined for normal operation & shut-down settings? _____ ____PSIG (barg): Bearing & Seal Balance LineOperating Shut-Down N/A

43. Has the Packager’s representative reviewed the Packager’s Start-Up and Operating Instructions for the unit with the unit operator? _____ _____

Check List - After Starting YES NO

1. When idle speed is achieved, immediately load compressor to 25%minimum slide valve axial position & increase minimum driver speed if necessary to stabilize load. Did the compressor bearing oil pressure come up immediately after loading compressor? _____ _____

2. Are the oil filters, bearing, mechanical seal, rotor injection, separator and gas balance line pressure gauges working? _____ _____

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Compressor Model AR-__________ Serial No. R-___________ Slide Valve Vi ________

Check List - After Starting YES NO

3. Are the oil filter differential pressures less than 30 psi (2.1 barg), unless otherwise specified. ____ ____

4. Did the compressor develop discharge pressure when moving slide valve from unloaded to loaded position? ____ ____

5. Has the oil side of the slide valve control cylinder been purged of gas and slide valve moved to an appropriate load position? ____ ____

6. After the slide valve is in an appropriate load position, does it hold that position? ____ ____

7. Have compressor oil system regulating valves been adjusted for minimum required bearing and slide valve hydraulic pressures? ____ ____

8. Any strange noises or shaking in the compressor or piping? ____ ____9. Is the compressor system oil level within acceptable limits? ____ ____10. Are bearing and balance oil pressure above minimum

pressure required for current operating condition? ____ ____11. Is the high discharge temperature shutdown working? ____ ____12. Is the high discharge gas temperature shutdown set at approx.

10% above normal discharge temperature? 248°F (120°C) max. ____ ____13. Is the mechanical seal weep hole leaking oil? Drops/minute. ____ ____14. Are there any other oil leaks? If so, where? ____ ____15. Are the scrubber dumps and high level shutdowns working? ____ ____16. Are the scrubber dumps removing all liquids from the gas without

obvious carryover? ____ ____17. Are there sands, oxides or other solid contaminants in the gas? ____ ____18. Is the overspeed shutdown set? ____ ____19. Is the mechanical seal sealing oil and gas properly at the shaft? ____ ____20. Has needle valve on separator filter scavenged oil line been

adjusted to show primarily gas movement at flow indicator? ____ ____21. Has counter thrust gas balancing pressure been adjusted for current

operating conditions? ____ ____22. Have all package safety functions been tested to ensure unit

shutdown upon malfunction? ____ ____23. After running compressor for 24 hours, are oil filter and separator

differential pressures less than maximum allowable? ____ ____24. Upon shutdown verify that compressor does not run in reverse

rotation for more than 2 seconds to assure check valve operation? ____ ____25. Has initial compressor operating data been recorded? ____ ____26. Has Ariel’s “Compressor Warranty Notification and Installation

List Data” form and a copy of this Start-up Check List and Log Sheet been completed and mailed to Ariel? ____ ____

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Company/Location Unit Compressor Model AR-__________ Serial No. R-___________ Slide Valve Vi ________

Remarks:

TABLE 3-1: TYPICAL LOG SHEET

���������

Operator

Suction Pressure, psig (barg)

Suction Temperature, °F (°C)

Discharge Pressure, psig (barg)

Discharge Temperature, °F (°C)

Driver Speed, RPM

Compressor Speed, RPM

Slide Valve Axial Position (% or number of turns)

Gas Flow Rate, MMSCFD (m3/sn)

Driver Load, HP (kW)

Bearing Oil Pressure, psi (barg)

Bearing Oil Filter Differential, psi (barg)

Compressor Bearing Oil Supply Tem-perature, °F (°C)

Rotor Injection Oil Filter Differential, psi (barg)

System Oil Temperature, °F (°C)

Gas Balance Pressure, psig (barg)

Separator Coalescing Filter Differential, psi (barg)

Coalescing Scavenged Oil Line Valve Adjusted & Flow Observed

Mechanical Seal Weep Rate,drops/minute

System Oil Level

Compressor Oil Added, gal. (L)

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Maximum Allowable Working Pressure

All Ariel Rotary Compressors have a "Maximum Allowable Working Pressure (MAWP)." The MAWP, the hydrostatic test pressure, and the test date are stamped on every rotor housing, adjacent to the suction cover or on the suction end (see Figure 1-7: on page 1-8).

API Standard 619, Third Edition, June 1997, Paragraph 3.1.18 defines "Maximum Allowable Working Pressure" as follows:

"Maximum allowable working pressure (MAWP): The maximum continuous pressure for which the manufacturer has designed the equipment (or any part to which the term is referred), when handling the specified fluid at the maximum specified temperature."

Relief Valve Settings

It is the responsibility of the packager to provide relief valves to protect equipment, piping and oil separator in compliance with API Standard 619, paragraphs 5.4.3.6.1 and 5.4.3.6.3.

Maximum relief valve settings are not to exceed the MAWP rating of the compressor or pip-ing components whichever is less.

Filling and Priming an Oil Lube Oil System - Before Start-ing

Filling The System1. Fill the oil filters, piping and gas/oil separator to a level high on the sight glass.2. Run the prelube pump to assure system is filled, and bearings and seals are

pre-lubed. Bleed piping and cooler high points vents to remove trapped air pock-ets. Check sight glass on separator. Oil level at start-up could be high or low on the site glass depending on component elevation. DO NOT OVERFILL. Proper oil system level is to be checked after compressor is operating when tempera-tures and pressures have stabilized and should be mid-point of the site glass, during normal operation.

CAUTIONOPERATING CONDITIONS MUST NOT EXCEED COMPRES-SOR DESIGN LIMITATIONS.

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Slide Valve Positioning - Hydraulic

On compressors furnished with hydraulically positioned slide valves, valve position may be hydraulically changed, from 100% to minimum axial position with the compressor running or stopped, to adjust the compressor's capacity. Hydraulic pressure, at a pressure greater than discharge pressure, is used to move the slide valve in an unload direction. Spring tension and/or discharge pressure exert a force on the slide valve in the load direction. Individual compressor package design determines whether slide valve hydraulic oil is ported with man-ually operated valves or is integrated into the control system's automation using remote actuated valves. Refer to Figure 3-1: on page 3-9.

Theory of OperationTo unload, open the “in” shutoff valve (bottom connection) with the “out” shutoff valve closed (top connection). Compressor oil enters the hydraulic cylinder moving the slide valve toward the discharge end to unload.

To hold, close both the “in” and “out” shutoff valves. Oil is captured in the cylinder and holds the slide valve in position.

To load, open the “out” shutoff valve with the “in” shutoff valve closed. Discharge gas moves the slide valve toward the suction end, discharging oil into the rotor housing to load.

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Visual Position Indicator (Yellow Pointer), Internally Changeable ModelsThe yellow pointer provides visual indication of the slide valve's axial position from 0% to 100%. The axial position is set to 0% for start-up, and is then adjusted for 25% to 100% for continuous operation. (Refer to Figure 3-1:). The pointer is shaft mounted with a set screw friction fit and can be adjusted for accuracy to match 0% or 25% and 100%. See "Slide Valve Axial Position Indicator Transducer" on page 5-8 for more details.

Visual Position Indicator (Yellow Pointer), Externally Change-able ModelsThe yellow pointer provides visual indication of the slide valve’s axial position from 20% to 100%. A 20% position stop limits the travel to a 20% minimum position and the slide valve spring is not used. (Refer to Figure 5-9: on page 5-11 and Figure 5-10: on page 5-11 for Hand Wheel Controlled and Hydraulically Controlled versions, respectively). The axial posi-

FIGURE 3-1: SLIDE VALVE AXIAL POSITIONING - TYPICAL HYDRAULICALLY CONTROLLED INTERNALLY CHANGEABLE Vi

0%

Oil - Out

Oil - In Control Piston at 25%

Slide Valve at 25%

25% 100% (Full Load)

Axial Position Indicator

25% Axial Position - Min. Continuous Load

0% (Unloaded)

Axial Position Indicator - Pointer

100% Axial Position - Full Load

Yellow Pointer

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tion is set to minimum (20%) for start-up and is then adjusted for 25% to 100% for continu-ous operation. The pointer is shaft mounted with a set screw friction fit and can be adjusted for accuracy to match 20% or 25% or 100%. See See “Slide Valve Axial Position Indicator Transducer” on page 5-8. for more details.

NOTE: WHEN THE Vi SPACER IS CHANGED, THE INDICATOR RANGE STICKER MUST ALSO BE CHANGED.

Slide Valve Positioning at Start-upPrior to starting, operate the prelube oil pump to provide control cylinder hydraulic pressure and position hydraulic valve to move slide valve to the minimum (unloaded) position, see Figure 4-1: on page 4-3. Position the hydraulic valve to maintain slide valve in the minimum position during start-up. Position other oil system valves, as required, for normal operations.

After starting, and as soon as idle speed is achieved, immediately load compressor to 25% minimum slide valve axial position which is done by removing oil from the cylinder. The slide valve's internal spring will position the internally changeable slide valve, or the fixed stop for externally changeable, to approximately the 20% axial position, then the developed dis-charge gas pressure will continue to move the slide valve toward the full load position. When the 25% position is achieved, position hydraulic valve to hold the slide valve at this position. Bearing oil pressure and discharge pressure should increase immediately after loading the compressor.

NOTE: COLD OIL EXITING THE CONTROL CYLINDER WILL DRAMATICALLY INCREASE SLIDE VALVE POSITIONING TIME COMPARED TO HOT OIL. IT MAY BE NECESSARY TO HEAT TRACE AND INSULATE CONTROL CYLINDER OIL TUBING LINES FOR COLD WEATHER APPLICATIONS.

After compressor is up to rated speed, the slide valve may be moved to an appropriate load position by operating the hydraulic valve to relieve hydraulic oil pressure in the cylinder. Dis-charge gas pressure will move the slide valve toward the full load position. See "Theory of Operation" on page 3-8 for more details regarding unload, hold & load.

NOTE: ANY OIL LEAKAGE OUT OF THE SINGLE ACTING CONTROL CYLINDER OR ACROSS THE CONTROL PISTON SEALING RING WILL MOVE THE SLIDE VALVE TOWARD THE FULL LOAD POSITION.

Slide Valve Positioning - Hand Wheel

The slide valve position may be manually changed, from 100% to 20% axial position with the compressor running or stopped, to adjust the compressor's capacity. A manual hand wheel is used to move the slide valve in both load and unload directions, using a non-rising stem design. A stem locking device is used to hold the slide valve in a given position. The slide valve's axial position is determined by counting the number of hand wheel turns, as shown in Table 1-2 on page 1-7. Refer to Figure 3-2: on page 3-12.

The slide valve cylinder piston's seal ring is designed for oil pressure containment. Filtered, pressured compressor oil is connected to the control cylinder, on the slide valve piston's

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hand wheel side, as a balancing force during hand wheel operation. Discharge pressure always exerts a force on the slide valve in the load direction. Refer to Figure 4-2: on page 4-4 for the balance oil connection details.

For ease of hand wheel operation the cylinder uses a balancing oil line, to allow for oil dis-placement and oppose discharge pressure forces on the slide valve. Oil fills the control cyl-inder as the slide valve moves toward the discharge end (unload position), and oil empties from the control cylinder as the slide valve moves toward the suction end (load position). Fil-tered oil also lubricates the piston's wear bands and sealing ring.

This slide valve cylinder design may allow for the conversion between manual & hydraulic slide valve operation, with a minimum of conversion components. Contact Ariel for conver-sion details.

Theory of OperationTo unload the compressor, the slide valve can be adjusted when the compressor is pressur-ized and operating. To adjust capacity, loosen the stem locking device, so the stem is free to turn. Turn the stem by using the hand wheel on the outboard shaft end. When facing the hand wheel, turn the wheel counter-clockwise to unload, moving slide valve toward dis-charge end.

To hold the slide valve position, re-tighten the stem locking device to the torque value shown in Table 1-4 on page 1-10.

To load the compressor, the slide valve can be adjusted when the compressor is pressurized and operating. To adjust capacity, loosen the stem locking device, so the stem is free to turn. Turn the stem by using the hand wheel on the outboard shaft end. When facing the hand wheel, turn hand wheel clockwise to load, moving slide valve toward suction end.

To hold the slide valve position, re-tighten the stem locking devise to the torque value shown in Table 1-4 on page 1-10.

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Slide Valve Positioning at Start-upPrior to starting, unload the compressor by moving the slide valve to a 20% axial position against the internal stop pin (refer to Figure 3-2:). After starting and when compressor is at rated speed, move the slide valve to a load position appropriate for the operating conditions. See "Theory of Operation" on page 3-11 for more details regarding unload, hold and load.

Balance Oil ConnectionBeginning December, 2000, all AR model rotary compressors with the hand wheel option are shipped with the slide valve cylinder’s balance oil connections plugged. The Packager is responsible for installing this line to the rotor injection oil supply, downstream of appropriate filtration but upstream of the rotor injection oil flow check and regulating valves. Refer to Fig-ure 4-2: on page 4-4 for a detailed illustration of oil flow.

Compressors with hand wheel capacity control can change the slide valve’s axial position by manually turning the hand wheel, in both the load and unload directions, between 100% (full load) and 25% (minimum continuous load). Discharge pressure always exerts a force on the slide valve, in the load direction, that is opposed by balance oil pressure. Filtered, pressur-ized compressor oil is connected to the slide valve control cylinder, on the piston’s hand wheel side, as a balancing force during hand wheel operation.

For ease of hand wheel operation, the cylinder uses a balancing oil line to allow for oil dis-placement and to oppose discharge pressure forces on the slide valve. Oil fills the control cylinder as the slide valve moves toward the discharge end (unload position) and oil empties from the control cylinder as the slide valve moves toward the suction end (load position). This filtered oil supply also lubricates the piston’s wear bands and sealing ring.

FIGURE 3-2: SLIDE VALVE AXIAL POSITIONING - TYPICAL HAND WHEEL CONTROLLED

Hand Wheel Balance Piston Balance Cylinder

Vi Spacer Slide Valve 20% Position Stop

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Ariel recommends using rotor injection oil for control cylinder balancing because this pres-sure is approximately discharge pressure. This pressure balance minimizes the manual torque requirement when unloading the compressor. Earlier designs, with balance oil tubed from the bearing oil supply resulted in excessive torque requirements when this pressure was substantially less than the discharge pressure.

During operation, compressor oil is always diluted by process gas, similar to a carbonated drink. Gas will flash out of the oil as pressure is reduced. The presence of flashed gas in the control cylinder can result in a compressible gas pocket in the control cylinder. A large gas pocket can generate alternating loads on the hand wheel’s threaded rod that may result in galled threads and difficulty adjusting slide valve position. Ariel recommends connection of the balance oil tubing to the cylinder’s top port. A top connection acts like a high point vent as oil exits the cylinder. The bottom connection can still be used for manual oil draining of the control cylinder. Refer to Figure 3-3: for balance oil connection details.

Built In Volume Ratio Changes - Internally Changeable Vi

With an internally changeable volume ratio (Vi) slide valve cylinder, the compressor's built in Vi can be changed by installing the appropriate slide valve. There are four different slide valve volume ratios (Vi = 2.0, 2.6, 3.5, 4.8) that are interchangeable within each compressor model. Control cylinder removal is required to access the slide valve to piston rod bolted connection for slide valve replacement. Compressors, equipped with internally changeable slide valves, are supplied with a specific slide valve Vi to match the initial operating condi-tions. If operating condition changes requiring a change in Vi, it will be necessary to pur-chase a new slide valve with the required Vi.

Refer to Section 5 - Maintenance for illustrations and details.

������ ���� ����� ���� ������ �� ��� ���

Crank Handle

Balance Oil Connection

Balance Piston

Balance Cylinder

Hand Wheel

Oil Drain Plug Cylinder

Mounting Bolts

Vi Spacer Oil Drain Plug

Slide Valve 20% Position Stop

Locating Dowel

Lock washer and Nut

3/02 PAGE 3 - 13

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 3 - START UP

Built In Volume Ratio Changes - Externally Changeable Vi

With an externally changeable volume ratio (Vi) slide valve cylinder, a fixed Vi slide valve is used but does not have to be changed out as does the internally changeable type. The com-pressor's built in Vi can be changed by installing the appropriate external Vi spacer (Vi = 2.2, 2.6, 3.5, 4.8), which locates the slide valve (discharge port) at the required volume ratio position. Compressors, equipped with externally changeable slide valves, are supplied with all shim-spacers and the hardware required to adjust to all Vi options.

Refer to Section 5 - Maintenance for illustrations and details.

Thrust Balance System

The thrust balance pressure system provides an adjustable counter thrust force to maximize male rotor thrust bearing life. The thrust balance system consists of a tubing line connected to discharge pressure, an adjustment valve and a pressure gauge to apply a specific pres-sure to the balance piston mounted on the male rotor's suction end.

NOTE: FAILURE TO SET THE BALANCE LINE PRESSURE FOR THE CURRENT OPERATING CONDITIONS WILL SIGNIFICANTLY DECREASE THE LIFE EXPECTANCY OF THE THRUST BEARINGS. ARIEL STRESSES THE IMPOR-TANCE OF PROPERLY ADJUSTING AND MAINTAINING THRUST BALANCE PRESSURES TO OPTIMIZE MALE ROTOR THRUST BEARING LIFE AND TO PREVENT PREMATURE BEARING FAILURE.

Thrust Balance Pressure AdjustmentRotor thrust forces on a rotary compressor are a function of suction pressure, discharge pressure and installed volume ratio. Ariel rotary compressors are furnished with a thrust-bal-ancing feature that allows the application of an opposing thrust force, through the use of adjustable gas pressure against a thrust balance piston. This balance piston is mounted on the male rotor’s suction end. When balance gas pressure is applied, bearing thrust is reduced. Maintaining a thrust balance pressure appropriate for current operating conditions is important to minimize thrust loads and to achieve long term compressor run time. The Ariel Rotary Screw Performance program provides target thrust balance pressures.

A change in compressor thrust force is more dependent on a change in suction pressures than on a change in discharge pressures. Maintaining proper thrust balance pressures on compressors with a normal operation suction pressure of 30 psig (2.1 barg) and higher should be given utmost attention. Generally, a slightly higher thrust balance pressure than the target pressure is best. Ariel’s target thrust balance pressure is the minimum pressure setting for a given set of operating conditions.

Thrust balance pressure is read on the gauge shown in Figure 3-4:. The pressure is adjusted by opening or closing the manual valve. Check the thrust balance pressure as part of the daily routine and adjust the pressure to match the target pressure for the current oper-ating conditions.

PAGE 3 - 14 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 3 - START UP

Gas/Oil Separator Coalescing Filter - Scavenged Oil Line Flow Adjustment

The gas/oil separator coalescing filter removes residual oil from the discharge gas stream. The oil scavenge line is necessary to minimize oil accumulation on the downstream side of the coalescing filter. A metering valve, check valve, flow indicator and a 75 micron (0.003 in.) strainer or filter are to be located in the scavenged oil line to return the downstream coalesc-ing filter oil to the compressor. See Figure 4-1: on page 4-3 and Figure 4-2: on page 4-4. With the compressor at normal operating conditions, adjust the valve to show gas flow movement into the compressor with minimal oil inclusion. If 100% of coalesced oil is not removed from the downstream side of the filter, the oil level will increase. The result is oil carry-over due to reduced filter cross-sectional area and excessive gas velocity through the filter. Excessive scavenged gas flow will reduce compressor performance due to the recy-cled gas. Insufficient scavenged oil flow will reduce coalescing filter performance resulting in oil carry-over with discharge gas stream.

Sour Gas Service with over 100 ppm to 2% H2S or Other Dangerous Gases

It is not recommended that single seal Ariel rotary screw compressors be used in Sour Gas Service with over 100 ppm H2S or other dangerous gas service. Single seal Ariel rotary screw compressors may not be used in Sour Gas Service over 2% H2S.

FIGURE 3-4: THRUST BALANCE PRESSURE GAUGE AND ADJUSTMENT VALVE

Thrust Balance Pressure Gauge

Balance Pressure Adjustment Valve

3/02 PAGE 3 - 15

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 3 - START UP

If an Ariel rotary screw compressor is used in H2S sour gas (between 100 ppm to 2%) or other dangerous gas service, it is the responsibility of the end user to provide all the neces-sary safety equipment, procedures and training to protect personnel from gas leakage. When operating Ariel Rotary compressors in dangerous gas service, at shutdown the com-pressor must be immediately blown down to remove all dangerous gases, i.e. vented, and/or purged with a non-toxic gas to prevent danger to personnel.

Compressor Re-Application

NOTE: IF ANY OF THE CONDITIONS LISTED BELOW CHANGE, CONSULT YOUR PACKAGER AND/OR ARIEL FOR ANY HARDWARE AND/OR DOCUMENTA-TION CHANGES THAT ARE REQUIRED. PERFORMANCE, VOLUME RATIO, OIL PUMP FLOW AND LUBE OIL RATE MUST BE RE-CALCULATED.

1. Gas pressures, temperatures or flow requirements.2. Gas properties.3. Driver type, speed or torque.4. Re-location of compressor to a different site.

PAGE 3 - 16 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260

SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

General

The oil system is vital for successful operation of rotary screw compressors and deserves special attention in the package design and operation. Ariel oil flooded rotary screw com-pressors utilize a pressurized, filtered, recirculation oil system. Oil is supplied to the com-pressor thorough rotor injection and various oil connections.

Oil flooding of the compression chamber is supplied at rotor injection. Pumped oil supplies lubrication to the bearings, oil to the mechanical seal and provides hydraulic power to posi-tion the slide valve. Pumped oil is scavenged in the compression chamber at an internal pressure less than rotor injection. The compressor oil system provides the following major functions:

1. Seals the internal running clearances and mechanical seal.2. Absorbs the heat of compression.3. Lubrication of rotors, bearings and mechanical seal.4. Hydraulic power - to move slide valve.

The process gas will dilute the oil, both mineral and synthetic, resulting in reduced viscosity. The pressurized oil viscosity reduction can be predicted and will remain stable provided that gas composition, pressure and temperature do not change and that any liquids are effec-tively removed from the gas prior to compressor suction.

Careful consideration must be given to proper lubrication selection. The degree of compres-sor oil dilution/saturation by the process gas stream is influenced by the following factors:

1. Process gas composition/Specific Gravity (SG) - usually the higher the SG, the greater the oil dilution.

2. Discharge gas pressure - the higher the pressure, the greater the oil dilution.3. Discharge gas temperature - the higher the gas/oil separator reservoir tempera-

ture, the less the oil dilution.4. Lubricant selection - some oil types are more prone to dilution.

Lubricants commonly used in oil flooded rotary compressors include petroleum based oils and synthetic fluids. Lubricant additives are used to improve the viscosity index, inhibit oxi-dation, depress the lubricant pour point, inhibit rust formation, improve detergency, provide anti-wear protection, provide extreme pressure protection, improve “lubricity”, decrease effects of gas dilution, increase “wetability”, and resist “washing” of the lubricant due to water, wet or saturated gas, or dilutive properties of the gas stream.

• Viscosity index is a measure of the ability of an oil to resist the thinning effect caused by increasing the oil temperature.

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

• Lubricity is the “slipperiness” or ability of a lubricant to decrease friction.• Wetability is a measure of the ability of the lubricant to adhere to metal surfaces. An

increase in wetability increases the lubricants’ resistance to “washing” effects.Pressure gauges are required for monitoring pressure drop across all oil filters.

Compressor oil should be changed at regular maintenance intervals or when oil sample results indicate the need. A more frequent oil change interval may be required if operating in an extremely dirty environment or if the oil supplier recommends it. Oil sampling should be performed on a regular basis to verify suitability of oil for continued service. Degradation to the next lower viscosity grade below the original viscosity or an increase in viscosity to the next higher grade requires a complete oil change.

NOTE: THESE OIL RECOMMENDATIONS ARE GENERAL GUIDELINES. IF THE REC-OMMENDED LUBRICANTS OR FLOW RATES DO NOT APPEAR TO WORK ADEQUATELY, FLOW RATES AND/OR LUBRICANT TYPES MAY NEED TO BE CHANGED. PLEASE CONTACT THE OIL SUPPLIER FOR SPECIFIC LUBRI-CANT RECOMMENDATIONS.

Lubricants

It is not Ariel’s policy to recommend any particular type or brand of oil. There are many com-panies who specialize in recommending blended or synthetic oil for a given application. These consultants given the gas composition analysis and operating conditions conduct proprietary flash gas and dilution calculations to determine proper lubrication and heat removal, as well as oxidation inhibition, rust and corrosion inhibition, and anti-wear proper-ties. Use of an experienced reliable lubricant consulting service is recommended.

Compressor bearings are designed to operate with an optimum kinematic viscosity of 112 SUS (23 cSt) at compressor casing oil inlet port.

• The minimum kinematic viscosity at operating conditions is 80 SUS (15 cSt). Com-pressor operation with oil viscosity below 112 SUS (23 cSt) will cause lubrication and sealing deterioration.

• The maximum kinematic viscosity at operating conditions is 142 SUS (30 cSt). Once a rotary compressor oil viscosity is selected, operating viscosity is affected by temper-ature and pressure in the gas/oil separator, plus ingested liquid contaminants in the suction gas stream.

Additives must not be corrosive to lead or copper base bearing materials.

Automatic transmission fluids (ATF) and used engine oils are not to be used for rotary com-pressor oils.

PAGE 4 - 2 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

T

AA

FIGURE 4-1: TYPICAL LUBE OIL SYSTEM - HYDRAULIC SLIDE VALVE CONTROL CYLINDER

ABLE 4-1: ILLUSTRATION LEGENDS FOR FIGURE 4-1

GAS CONNECTIONS OIL CONNECTIONS PUMP CONNECTIONS INSTRUMENTATION SYSTEM COMPONENTS

1. Suction Flange2. Discharge Flange

B1. Main Oil SupplyB2. Rotor Oil Injec-tion - FemaleB3. Rotor Oil Injec-tion - MaleB4. Scavenge OilB5. Mechanical Seal/Thrust Bearing Oil

P1. Oil Pump SuctionP2. Oil Pump Dis-charge

PI. Pressure Indica-torPDSLL. Pressure Differential Switch LoLo - Oil SupplyTE. Temperature ElementTSHH. Temperature Switch - HiHi (Oil Supply/Discharge)

1. Inlet Scrubber2. Check Valve3. Strainer - Conical, Gas4. Shutoff Valve5. Flow Indicator6. Relief Valve7. Pressure Control Valve8. Needle Valve - Flow Control9. Prelube Pump10. Integral Oil Pump- Female Rotor Drive

11. Coalescing Filter12. Differential Pressure Gauge/Indicator13. Oil Filter14. Orifice15. Temp Control Valve16. Back-Pressure Con-trol Valve17. Unload Valve - Oil In18. Loading Valve - Oil Out19. Oil Strainer-60 Mesh20. Trim Valve - Temp Control Valve

High Lo

Piping By Ariel

Piping By Pkgr.

Vent to Safe Atmo-sphere

Process Gas Dis-charge

Gas/Oil Separator

To Rotor Injection

Oil Cooler

To Mech anical Seal w/ Orifice

Lube Oil

Ariel Twin Screw Rotary Compressor

Slide Valve Hydrau-lic Cylinder

To Scav-engerFrom Separator

Load

Process GasSuction

3/02 PAGE 4 - 3

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

TAB

GA

A1. A2.

e

l

-

shra-

FIGURE 4-2: TYPICAL LUBE OIL SYSTEM - HAND WHEEL SLIDE VALVE CONTROL

LE 4-2: ILLUSTRATION LEGENDS FOR FIGURE 4-2

S CONNECTIONS OIL CONNECTIONS PUMP CONNECTIONS INSTRUMENTATION SYSTEM COMPONENTS

Suction FlangeDischarge Flange

B1. Main Oil SupplyB2. Rotor Oil Injec-tion - FemaleB3. Rotor Oil Injec-tion - MaleB4. Scavenge OilB5. Mechanical Seal/Thrust Bearing Oil

P1. Oil Pump SuctionP2. Oil Pump Discharge

PI. Pressure IndicatorPDSLL. Pressure Dif-ferential Switch LoLo - Oil SupplyTE. Temperature Ele-mentTSHH. Temperature Switch - HiHi (Oil Sup-ply/Discharge)

1. Inlet Scrubber2. Check Valve3. Strainer - Conical, Gas4. Shutoff Valve5. Flow Indicator6. Relief Valve7. Not Used8. Needle Valve - Flow Control9. Prelube Pump10. Integral Oil Pump - Female Rotor Drive11. Coalescing Filter

12. Differential PressurGauge/Indicator13. Oil Filter14. Orifice15. Temperature ControValve16. Back-Pressure Control Valve17. Not Used18. Loading Valve - Oil Out19. Oil Strainer - 60 Me20. Trim Valve - Tempeture Control Valve

Oil Cooler

To Rotor Injection

To Slide Valve Cylinder - Bal-ance Line - Bi-Directional Oil Flow

Slide Valve Hand Wheel Cylinder

Ariel Twin Screw Rotary Compressor

ToScavenge

FromSeparator

Process Gas Suction

Piping By Ariel

Piping By Pkgr.

Vent to Safe Atmo-sphereProcess Gas Dis-charge

Gas/Oil Separator

To Mechanical Seal w/ Orifice

Lube Oil

PAGE 4 - 4 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

Petroleum Based Oils - also referred to as mineral oils: Paraffinic - higher wax content, better resistance to thinning at higher operating tempera-tures than napthenic.

Napthenic - (as compared to paraffinic) lower wax content, better flowability at low tempera-tures for cold start-ups, lower resistance to thinning at higher operating temperatures, better solvency, lower life/oxidation stability.

Animal fat and vegetable oil additives are not be used in rotary screw compressors.

Synthetic Lubricants Synthetic lubricants are man-made materials with more consistent, controlled chemical structures than petroleum lubricants. This improves predictability of viscosity and thermal stability. Synthetic lubricants can be designed with better dilution resistance, better oxidation resistance, better lubricity, better film strength, natural detergency, lower volatility, and results in decreased operating temperatures. These attributes can help to decrease rotor injection feed rate requirements. Justification for the use of synthetic lubricants is based on energy savings, reduced lubricant usage, increased component life, decreased equipment downtime, and reduced maintenance/labor. Some synthetic lubricants can be used in the compressor lubrication. Consult with the lubricant supplier before using these lubricants in the compressor.

• Synthesized Hydrocarbons - polyalphaolefins (PAO) can be used as compressor lubricants: 1. Compatible with mineral oils. 2. Compatible with viton.3. Generally not water soluble.4. Diluted by heavy hydrocarbon gases.5. Requires additives to improve detergent action and improve seal compatibility. 6. Soluble in some gases. Verify application with lubricant supplier. 7. Compatible with Viton and HNBR - Buna N (high end acrylonitrile-butadiene).

• Organic Esters - diesters and polyolesters: 1. Compatible with mineral oils 2. Incompatible with some rubbers (O-rings), plastics, and paints. Compatible with

Viton. 3. Primarily used in air compressors.

• Polyglycols - polyalkylene glycols (PAG), polyethers, polygylcolethers, and polyalky-lene glycol ethers: 1. Not compatible with mineral oils, some plastics and paints. Requires com-

plete system flush when changing to or from polyglycols. Contact oil sup-plier for flushing details.

2. Can be water soluble - must verify application with lubricant supplier. 3. Resistant to hydrocarbon gas dilution. Excellent wetability. 4. Poor inherent oxidation stability and corrosion protection - requires additives.

3/02 PAGE 4 - 5

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

5. Compatible with Viton and HNBR - Buna N (high end acrylonitrile-butadiene). 6. Not recommended for air compressors.

Auxiliary Equipment

Lube Oil StrainerThe strainer is located between the pump suction and the oil cooler. The strainer basket should be taken out and washed in an appropriate solvent whenever the lubricating oil is changed.

Oil CoolerAll compressors must have an oil cooler. Maximum allowable oil temperature into the com-pressor is determined by the process gas dew point, operating conditions and the type of oil. Oil temperature into the compressor is recommended to be 150°F (65°C). The packager is responsible for sizing a proper oil cooler. Operating conditions which must be taken into account are; the cooling medium, cooling medium temperature, cooling medium flow rate, lube oil temperature, lube oil flow rate, gas temperatures and gas compression capacities. Oil heat rejection data for each application is determined from the Ariel Rotary Com-pressor Performance Program (contact your Packager or Ariel when you need this infor-mation). The cooler should be mounted as close to the compressor as possible, with piping of adequate size to minimize pressure drop of both the oil and the cooling medium.

Temperature Control ValveFor proper operation of the oil system a temperature control valve is required. The maximum differential pressure between the hot oil supply line (point B) and the cooled oil return line (point C) is to be 10 psi (0.7 bar). Refer to Figure 4-1: Ariel recommends installation of the temperature control valve in the mixing mode.

The recommended oil injection temperature is 150°F (65°C) at the compressor oil inlet ports. An oil temperature of 150°F (65°C) is the minimum temperature required to drive off water vapor. Normally select a temperature control valve with a 150°F (65°C) nominal temperature setting. If operating conditions dictate otherwise, contact Ariel Application Engineering (refer to “Ariel Contact Information” on page7-10 for contact information.

Cold Ambient TemperaturesIf a compressor is exposed to cold ambient temperatures, the oil system must be designed so the unit may be safely started with adequate oil flow to the compressor bearings and mechanical seal. Temperature controlled cooler by-pass valves, oil heaters, cooler louvers and even buildings may be needed to assure successful operation.

Oil filter differential pressure increases significantly with oil viscosity greater than 2275 SUS (500cSt). The maximum viscosity of the lube oil for cold ambient temperature starting with-

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

out pump cavitation is 7,275 SUS (1600 cSt) provided that all external piping is heat traced and insulated. Minimum start up temperatures for full or semi-synthetic lubricants can be reduced based on viscosity index. Start up oil viscosity must be sufficiently low to prevent pump, filter, bearing or mechanical seal damage.

When electric oil immersion heaters are used with mineral oils, the watt density of the heater element should not exceed 5 watts per square inch (0.8 W/cm2) for systems without circulat-ing pumps. Oil coking will occur at the element with higher wattage heaters if a circulating pump is not used. When high wattage heaters are required, the heaters must be interlocked with an oil circulation pump to assure that coking of the oil will not occur. Coked oil will form deposits which can “insulate” the system and decrease heat removal. The deposits can also break loose and act as abrasives in the lubricating system. Synthetic oils may have higher coking temperature limits, contact your lubrication supplier for details.

Prelube PumpRotary compressors must have a prelube pump, to ensure bearing and mechanical seal oil flow, to refill oil filters after maintenance and to position the slide valve to 0% load prior to start-up, when hydraulic control cylinder equipped.

NOTE: THE MECHANICAL SEAL IS DESIGNED TO OPERATE WITH AN OIL FILM AND MUST BE PRE-LUBED PRIOR TO STARTING. THE SEAL MUST BE CONTI-NOUSLY SUPPLIED WITH OIL WHILE COMPRESSOR IS OPERATING. ANY DRY RUNNING OF SEAL, WITHOUT LUBRICATING OIL, WILL RESULT IN SCORING OF THE SEAL FACES AND REDUCED SEAL LIFE.

Oil Pressure Regulating ValvesThe oil pump is generally capable of supplying oil pressure and volume in excess of that required for a specific application. The pressure regulating bypass valve across the oil pump is used to supply an adequate oil volume to bearings, mechanical seal and hydraulically controlled slide valve cylinder, if so equipped, while bypassing the excess oil volume. A hydraulically controlled slide valve requires a minimum oil pressure approximately 45 psi (3.1 barg) above discharge pressure to unload the slide valve.

The second oil pressure regulating valve, used only with hydraulically controlled slide valve cylinders, reduces oil pressure for the bearings and seal while providing a back pressure for the hydraulic oil supply. Adjustments to the oil pressure regulating valve settings allow Ariel rotary compressors to be applied for a wide variety of operating conditions. Refer to “Com-pressor Oil Supply Pressure Calculations” on page 4-9 to determine proper settings.

Oil FiltersAriel recommends replacing filter elements before differential pressure reaches collapse pressure across the filter at normal operating temperatures or at six month intervals.

3/02 PAGE 4 - 7

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

Bearing, mechanical seal and control cylinder full flow filtration shall equal or exceed a 7 µm (micron) rating with a 75 Beta ratio (B7 = 75, 98.7% efficiency rating at removing 7 µm and larger particle size.

Rotor injection full flow filtration shall equal or exceed a 15 µm (micron) rating with a 75 Beta ratio (B15 = 75, 98.7% efficiency rating at removing 15 µm and larger particle size.

NOTE: FAILURE TO FILL FILTER VESSELS WITH OIL PRIOR TO STARTING, AFTER CHANGING FILTERS, CAN CAUSE SEVERE DAMAGE TO THE COMPRES-SOR.

Liquids and Contaminants in GasThe use of higher viscosity lubricants or specially compounded lubricants can compensate somewhat for the presence of liquids in the gas stream.

NOTE: WHEN THERE ARE FREE LIQUIDS AND CONTAMINANTS PRESENT IN THE GAS, THE MOST EFFECTIVE LUBRICATION OF ROTARY COMPRESSORS REQUIRES REMOVAL OF THE LIQUIDS AND CONTAMINANTS BY USING SCRUBBERS BEFORE THE GAS ENTERS THE COMPRESSOR.

To minimize compressor oil dilution, the gas/oil separator operating temperatures should be maintained about 20F° (11C°) above the process gas dew point temperature at discharge pressure, but not less than 150°F (65°C). A separator temperature of 150° (66°C) is the min-imum temperature required to drive water vapor into the process gas stream.

Compressor Oil Pump

For compressor oil pump sizing and flow verification, refer to the Ariel Performance Pro-gram.

The compressor integral oil pump is sized for the driver-compressor package speed range and gas application pressures, to provide adequate oil flow and pressure for the compressor within the driver’s normal speed range. Generally, minimum driver speed is based upon a speed versus horsepower or torque lug curve that determines compressor and oil pump minimum speeds.

The compressor oil pump is selected to provide adequate lubricating oil and slide valve posi-tioning hydraulic pressure at minimum driver speed and maximum compressor differential pressure. The integral compressor oil pump is direct driven by the female rotor, which has a lower rotating speed than the male rotor. Oil pump flow and pressure are determined by female rotor speed and oil pressure regulating valve adjustment.

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Male and female rotor speed limitations are as follows, in Table 4-3:, below. Minimum opera-tion drive speed to the compressor must not be less than the minimum male rotor speed limit.

Minimum bearing oil supply pressure and shutdown setting are based upon the differential pressure connection to the scavenged oil gallery. Refer to “Lube Oil Shutdowns” on page 4-10 for additional lube oil shutdown information.

Compressor Oil Supply Pressure Calculations

The compressor oil flows are based upon fixed internal clearances, except for mechanical seal supply which uses a fixed external orifice, supplied by Ariel. Adequate compressor oil flow is based upon measured oil pressure at the compressor connections.

Listed below are the minimum compressor oil pressure requirements: If control cylinder or bearing oil pressures cannot be met, contact your Packager or Ariel.

Where: Ps = Suction Pressure, absolute

Pd = Discharge Pressure, absolute

k = Ratio of Specific Heats for Process Gas in Service

1 psia = 1 psig + atmospheric pressure at elevation

1 (bara) = 14.5 psi

1. Slide Valve Control Cylinder Hydraulic Pressure (SVCP), minimum = Pd + 43.5 psia (or + 3 bara)

Example: If, Pd = 75 psia (5.2 bara),

SVCP = 75 + 43.5 = 118.5 psia

SVCP = 5.2 + 3 = (8.2 bara)

2. Bearing Oil Pressure (BOP), minimum = 1.5 Ps + 72.5 psi (or + 5 bara)

Example: If, Pd = 75 psia (5.2 bara), Ps = 25 psia (1.7 bara)

BOP = (1.5 x 25) + 72.5 = 110 psia

BOP = (1.5 x 1.7) + 5 = (7.6 bara)

TABLE 4-3: ROTOR SPEED LIMITS

COMPRESSOR MODEL

ROTOR GEAR RATIO, MALE

LOBES/FEMALE FLUTES

MINIMUM ROTOR SPEED, RPM

MALE/FEMALE

MAXIMUM ROTOR SPEED, RPM

MALE/FEMALE

AR166 5/7 1148/820 5739/4099

AR208 5/7 918/656 4591/3279

AR260K, AR260 5/7 735/525 3550/2366

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 4 - OIL SYSTEM, LUBRICATION & VENTING

3. Rotor Injection Pressure, approx. (RIP) = Ps x (1.9)k

Actual flow/pressure fluctuates with changes in bearing oil pressure.

Example: If, Ps = 25 psia (1.7 bara), k = 1.2

RIP = 25 x (1.9)1.2 = 25 x 2.16 = 54 psia

RIP = 1.7 x (1.9)1.2 = 1.7 x 2.16 = (3.7 bara)

Gas Balance Line Pressure (GBLP) Calculation

Ariel rotary compressors use regulated discharge gas pressure to provide a counter thrust force that reduces bearing load on the male rotor active thrust bearing. A minimum gas bal-ance pressure is determined by the Ariel Rotary Compressor Performance Program for an operating condition. Properly monitored and adjusted gas balance pressure is required to maximize thrust bearing life.

Example: If, Ps = 25 psia (1.7 bara), Pd = 75 psia (5.2 bara) at 1700 RPM

GBLP = 54 psig minimum

GBLP = (3.5 barg)

Compressor Re-Application

NOTE: IF ANY OF THE CONDITIONS LISTED BELOW CHANGE, CONSULT YOUR PACKAGER AND/OR ARIEL FOR ANY HARDWARE AND/OR DOCUMENTA-TION CHANGES THAT ARE REQUIRED. PERFORMANCE AND OPERATING PRESSURES MUST BE RE-CALCULATED:

1. Gas pressures, temperatures or flow requirements.2. Gas properties.3. Driver Type, speed or torque.4. Re-location or compressor to a different site.

Warranty

Warranty of component failures which occur while using lubricants which do not meet these specifications will be subject to review on a case by case basis.

Lube Oil Shutdowns

NOTE: THE COMPRESSOR MUST HAVE WORKING LOW OIL PRESSURE AND HIGH INLET OIL TEMPERATURE SHUTDOWNS.

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Pressure:Inadequate oil pressure and flow can cause catastrophic compressor damage.

Minimum bearing oil supply pressure alarm and shutdown settings are based upon the dif-ferential pressure connection to the scavenge oil gallery. The low differential oil pressure shutdown switch (low, low - PDSLL) is normally supplied and installed by the packager with a low side sensing connection into the scavenge oil gallery.

The normal bearing oil pressure is a value greater than 1.5Ps + 72.5 psi (+ 5 bara), see pre-vious examples at Bearing Oil Pressure (BOP) in “Compressor Oil Supply Pressure Calcula-tions” on page 4-9.

The bearings require a minimum oil supply pressure approximately 75 psig (5 barg) higher than the downstream (scavenge oil gallery) pressure to maintain adequate oil flow for lubri-cation and cooling. To maintain adequate flow during upset conditions, a shutdown setting of approximately 60 psig (4+ barg) falling pressure is recommended. See Figure 4-3: for an illustration of the connection points using a differential pressure shutdown (low, low - PDSLL).

FIGURE 4-3: DIFFERENTIAL PRESSURE SWITCH, LOW-LOW (PDSLL)

Bearing Oil Supply

PDSLL, High Side

Scavenge Oil Gallery PDSLL, Low Side

1/4” Tubing

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Ariel recommends the oil pressure switch be set to actuate when oil pressure falls below the following pressures:

Normal oil pressure > 1.5 x Ps + 72.5 psi (= 1.5 x Ps + 5 bara)

Alarm, psid = (1.5 x Ps + 65 psi), falling

[Alarm, bard = (1.5 x Ps + 4.5 bara), falling]

Shutdown, psid = (1.5 x Ps + 58 psi), falling

[Shutdown, bard = (1.5 x Ps + 4 bara), falling]

Temperature:The high oil temperature shutdown is to be located at the filter inlet connection. It is to be set 10% above normal oil inlet temperature.

Rotor Injection Flow

Rotor injection oil pressure and flow are a function of operation conditions, specifically suc-tion and discharge pressures and temperatures. See the Ariel Performance Program - gen-erated summary sheet for required rotor injection oil flow and gas discharge temperature for given operating conditions. Adjust rotor injection flow throttling valve to maintain the required minimum discharge gas temperature.

Reducing rotor injection flow will raise discharge gas and oil/gas separator temperature. Consult Ariel Application Engineering before reducing oil flow volume.

Flushing Requirements

Some synthetic and mineral based oils are not compatible. Use extreme care and refer to oil suppliers recommendations for draining and flushing the oil system when changing to or from a synthetic oil.

The compressor is tested at the factory using a synthetic - mineral based oil and prior to shipment protected with a vapor phase inhibitor in a mineral oil. These oils may not be com-patible with the oil selected for field use. Consult the oil supplier to determine if clean-out flushing is required.

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260

SECTION 5 - MAINTENANCE

General Introduction

The major components of the compressor are the rotor housing, discharge housing, rotors, bearings, mechanical seal, slide valve, thrust balance piston, oil pump and hydraulic slide valve control cylinder with slide valve position indicator (or slide valve control cylinder with hand wheel). The mechanical seal, slide valve, slide valve spacers, slide valve position indi-cator, and oil pump and coupling may be replaced in the field.

NOTE: DO NOT OTHERWISE DISASSEMBLE THE INTERNALS OF THE COMPRES-SOR. IF OTHER INTERNAL COMPONENTS NEED REPAIR, RETURN COM-PRESSOR TO ARIEL FOR OVERHAUL OR EXCHANGE.

Absolute cleanliness, including the use of lint-free wiping cloths, is a necessity during any maintenance on the compressor. When access covers have been removed, keep the com-pressor covered to protect the internal surfaces from debris except when actually working within it. Any components that have been removed should be protected from falling objects that might mar or chip machined surfaces.

Whenever the compressor is dismantled, o-rings at non-pressure positions are to be care-fully inspected before reuse, if damaged they should be replaced. O-rings at pressure loca-tions should be replaced. O-ring lubricants must be compatible with o-ring materials, lube oil and process gas.

CAUTIONTO PREVENT PERSONAL INJURY, ASSURE THAT COM-PRESSOR ROTOR CANNOT BE TURNED BY THE DRIVER ORGAS PRESSURE DURING MAINTENANCE: -- ON ENGINE-DRIVEN COMPRESSORS, REMOVE THE CENTER COUPLINGOR LOCK THE FLYWHEEL. -- ON ELECTRIC MOTOR-DRIVENCOMPRESSORS, IF IT IS INCONVENIENT TO DETACH THEDRIVER FROM THE COMPRESSOR, THE DRIVER SWITCHGEAR MUST BE LOCKED OUT DURING MAINTENANCE.

BEFORE STARTING ANY MAINTENANCE OR REMOVINGANY COMPONENTS, RELIEVE ALL PRESSURE FROM THECOMPRESSOR GAS AND OIL SYSTEMS. (SEE PACKAGER’SINSTRUCTIONS FOR COMPLETELY VENTING THE SYSTEM.

!

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Mechanical Seal

The mechanical seal prevents loss of internal process gas pressure, at the male rotor drive, around the shaft to the compressor exterior. The seal consists of a rotating inner ring which turns with the rotor and a spring loaded carbon seal assembly which is held stationary in the seal housing cover. Sealing is generated by the spring force and the hydraulic force of the lubricating oil pressure acting on the seal faces.

On compressor Models AR260 and AR260K, the mechanical seal’s stationary cartridge has no anti-rotation pin.

CAUTIONAFTER PERFORMING ANY MAINTENANCE, THE ENTIRESYSTEM MUST BE PURGED WITH GAS PRIOR TO OPERA-TION, TO AVOID A POTENTIALLY EXPLOSIVE AIR/GAS MIX-TURE.

FIGURE 5-1: MECHANICAL SEAL TOP VIEW - TYPICAL

!

O-Ring

Clamping Spacer

Seal Housing

Capscrew

Male Rotor Drive End

Stationary Carbon Seal - Spring Loaded Assembly

Rotating Seal - Inner Ring

O-Ring

O-Ring

Discharge Cover

Shaft Seal Lock Nut

Seal Housing Spacer Ring

Silicon Caulk - Thread Protection

Anti-Rotation Pin (AR166 & 208 Only)

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

On compressor Models AR166 and AR208, the mechanical seal’s stationary cartridge has an anti-rotation pin and can only be installed one way.

To install the rotating ring, pull it up against the shaft stop with clamping spacer. To install stationary cartridge into housing, use special tool. To install the mechanical seal housing, use a torque pattern to pull up square.

Thoroughly clean silicon thread caulk from the shaft. During reassembly, any caulk residue will be sheared by the clamping spacer and gunk may be forced into the seal’s contact face.

Do not use the shaft seal locknut as a holding (reaction) point when removing the coupling hub’s collared retaining bolt. Excessive tightening will buckle the thin-walled clamping spacer.

The mechanical seal must be kept free of oil and oily fingers. Oil attracts debris which can score the surfaces resulting in leaks and reduced service life.

NOTE: MECHANICAL SEAL CRITICAL SURFACES SUCH AS SEAL FACES, O-RING SEATS AND FITS MUST BE HANDLED WITH EXTREME CARE. REPLACE-MENT SEAL COMPOMENTS MUST BE TRANSPORTED AND STORED IN THE ORIGINAL UNOPENED PACKAGING. REPLACEMENT SEALS WHICH HAVE BEEN SUBJECT TO IMPACT, SUCH AS BEING DROPPED, ARE NOT TO BE USED. STORAGE MUST BE DRY, DUST FREE AND AT REASONABLE CON-STANT TEMPERATURE. SEALS STORED IN EXCESS OF THREE YEARS SHOULD BE RE-INSPECTED BEFORE BEING USED. DO NOT DISSASSEM-BLE THE SEAL - SPRING LOADED ASSEMBLY.

Replacing the Mechanical SealRemove thread protection caulking compound, located between the shaft seal lock nut and coupling hub, being careful not to damage threads. Hold rotor from turning, with drive train assembled coupling in place, and loosen the shaft seal locknut, using the special spanner wrench provided in the tool box (see Table 7-1: on page 7-2). Heating lock nut to 200°F max-imum (93°C) may be required to break Loctite seal. Disassemble the coupling center section and remove the coupling hub half and retaining bolt from the male rotor. Remove the shaft seal lock nut. Remove the 12 point cap screws that secure the seal housing cover to the dis-charge cover. Using the two jack bolts (M12 x 1.75 x 40mm or M16 x 2 x 55mm, class 12.9) provided in the tool box, jack seal housing cover loose. Slide the seal housing cover and clamping spacer off the rotor.

NOTE: BE CAREFUL TO PROTECT THE ROTOR THREADS FROM DAMAGE WHEN REMOVING AND INSTALLING MECHANICAL SEAL.

TABLE 5-1: SEAL AND SEAL HOUSING COVER APPROXIMATE WEIGHTS

MODELSEAL COVER

LB (kg) LB (kg)

AR166 5 (2) 15 (7)

AR208 9 (4) 25 (12)

AR260K, AR260 11 (5) 44 (20)

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Remove the inner seal ring and o-ring from the rotor.

Disassemble the seal housing cover internal parts, removing the spacer ring, seal - spring loaded assembly, both o-rings and jack bolts. Discard both mechanical seal elements, all three o-rings and lock nut. Clean parts, being careful to remove Loctite residue from rotor threads, external and internal, and coupling retaining bolt threads.

Reassemble using a new mechanical seal, three new o-rings and new lock nut. Lubricate o-rings with a high viscosity silicone fluid such as Parker Super-O-Lube or equal. Put o-ring and inner seal ring in position on rotor. On the AR166 and AR208 compressors, the seal - spring loaded assembly utilizes a dowel to help hold it stationary in the seal housing. This dowel normally does not need to be replaced. Replace both o-rings on the seal housing. Press seal - spring loaded assembly into seal housing. A cylindrical ring fixture to push against the seal housing provided in the Ariel tool box is required. Do not push against seal face or tap into place. Reassemble spacer ring and clamping spacer into seal housing.

Slide seal housing on to rotor, being careful to position leakage weep hole downward while aligning bolting holes. Install cap screws and tighten to torque values in Table 1-3 on Page 5-10.

Apply Loctite grade 222 (purple) to the first two external rotor shaft threads and assemble nut on to rotor, hand tight. Quickly, temporarily reassemble drive coupling hub and key, hand tight. Hold coupling hub to keep rotor from turning and tighten the shaft seal locknut, using the special wrench provided in the tool box to the proper torque value in Table 1-4 on Page 5-10. Working time for Loctite 222 is 10 minutes. Reassemble complete coupling to manu-facture’s instructions. Apply a bead of silicone caulking compound at the shaft to seal lock nut face covering all of the exposed shaft threads to help protect from impact damage and thread corrosion.

NOTE: THE COUPLING RETAINING BOLT TORQUE IS BASED UPON COUPLING DESIGN AND THE POWER TO BE TRANSMITTED. CONSULT PACKAGER’S INFORMATION FOR PROPER TORQUE VALUE.

Optional Collared Retaining BoltsAriel offers an optional Collared Retaining Bolt (CRB) for reduced torque compressor appli-cations. The CRB replaces the standard bolt and washer retaining bolt design that was orig-inally developed for high horsepower applications that require the use of a special coupling hub design.

The CRB is a low profile design for use on AR Series rotary compressor drive coupling hubs. It minimizes the coupling hub counterbore depth for selected coupling designs and allows the use of the standard, semi-finished coupling hubs that are typical for reduced torque, nat-ural gas applications.

Refer to Ariel’s Engineering Reference ER-41 “Rotary Compressor - Coupling Hub Installa-tion & Retention” for details and application limitations for the use of CRBs.

Installation and removal of the CRB requires the use of an Ariel supplied torquing adapter tool. This tool adapts to standard 1/2” and 3/4” drive torque wrenches and applies torque

PAGE 5 - 4 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

using dowel pins. (Refer to Figure 5-2: Collared Retaining Bolt Assembly and Figure 5-3:

Collared Retaining Bolt and assembly Tool.)

FIGURE 5-2: COLLARED RETAINING BOLT ASSEMBLY

FIGURE 5-3: COLLARED RETAINING BOLT AND ASSEMBLY TOOL

Mechanical Seal Lock Nut

Shaft Key

Male Rotor Shaft

Coupling Hub

Collared Retaining Bolt

2°51’45”

Collared Retaining Bolt

Assembly

Tool

Opening Sized for 3/4” Drive Ratchet

3/02 PAGE 5 - 5

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Slide Valve Replacement - Internally Changeable Vi

The slide valve may be changed, to provide a different volume ratio (Vi) that is appropriate for current operating conditions.

To replace the slide valve, move the slide valve to the full load (100%) position. The male rotor must be rotated so that the shaft keyway is at the top (12 o’clock position), which posi-tions rotor mesh for ease of slide valve cylinder assembly removal and reinstallation. Be sure that the compressor is properly vented and that the equipment is locked out so rotors can not turn. Remove oil lines from slide valve cylinder, and rotor housing drain plug to drain residual oil. Replace drain plug when oil stops running. Unbolt slide valve indicator or remove electrical connection, as required, to allow for slide valve cylinder removal.

FIGURE 5-4: HYDRAULIC INTERNALLY CHANGEABLE SLIDE VALVE 25% AXIAL POSITION - TYPICAL “N” VERSION

Axial Position Indicator

Axial Position Indicator

Oil Pump

Slide Valve

PAGE 5 - 6 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Compressors with Individual Cover PlatesIf your compressor design does not have a single suction-end cover do not pull the dowel pin, prior to disassembly. The slide valve cylinder with slide valve is removed using the jack bolting provided. Slinging parts to an overhead crane may be useful to assist removal. Remove control cylinder o-ring and discard.

ReplacementWith the slide valve at the 80% axial position, hold positioner piston rod with a strap wrench to prevent shearing the positioning dowel and remove the slide valve nut and lockwasher. Remove slide valve from the piston rod. Clean parts, being careful to remove Loctite residue from piston rod and nut threads.

Select a new slide valve with the proper volume ratio (Vi) required. Reassemble slide valve to piston rod with locating dowel properly aligned with the slide valve groove. Apply Loctite 222 (purple) to the first two piston rod threads and install lockwasher and nut. Hold the pis-ton rod with a strap wrench and tighten nut to the proper torque value in Table 1-4 on Page 5-10. Install a new o-ring lubricated with a high viscosity silicone fluid such as Parker Super-O-Lube or equal. Remove jack bolts.

Slide Valve Cylinder Reassembly Into CompressorInsert slide valve cylinder with attached slide valve into the compressor being careful to level the assembly and lift to put the slide valve on slide guide. On compressors with individual cover plate (“N”), reinstall the cylinder onto the dowel. Tighten capscrews to the proper torque in Table 1-3 on page 1-10. Remove lifting tool as required and replace thread protec-tion plugs or grease.

Reattach oil lines, thrust balance line and slide valve axial position indicator as required.

Stamp or vibra-etch the new volume ratio (Vi) and date on the volume ratio change plate. See Figure 1-7: on page 1-8, top view for plate location.

TABLE 5-2: HYDRAULICALLY CONTROLLED SLIDE VALVE - APPROXIMATE WEIGHTS

MODEL

SLIDE VALVE ONLY (INTERNALLY

CHANGEABLE)

SLIDE VALVE & CONTROL POSITIONER

CYLINDER

SUCTION COVER WITH CYLINDER & SLIDE

VALVE

LB (kg) LB (kg) LB (kg)

AR166 24 (11) 105 (48) 195 (89)

AR208 46 (21) 175 (80) 310 (141)

AR260K 75 (34) 230 (105) 420 (191)

AR260 85 (39) 260 (118) 525 (239)

3/02 PAGE 5 - 7

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Using the pre-lube pump, move the slide valve to the 0% position. Check the yellow visual position pointer for 0% indication. Calibrate if necessary.

NOTE: THE YELLOW POSITION POINTER IS A SLIDING FRICTION FIT ON THE INDI-CATOR SHAFT, TO ALLOW FOR CALIBRATION.

Slide Valve Axial Position Indicator Transducer

The slide valve axial position indicator transducer provides a visual indication dial (0 to 100%), 5 limit switches with adjustable cams and a precision potentiometer for monitoring the axial position of the slide valve. Switches 1 and 2 (pins 10 and 9) are single cam and cal-ibrated by Ariel to represent the 0 and 100% positions. Switches 3 thru 5 are provided so that up to five additional slide valve positions can be calibrated and monitored electronically. The position indicator transducer is also equipped with a precision wire wound potentiome-ter to monitor slide valve position. To calibrate the limit switch cams, use the adjustment wrench provided inside the position transducer indicator case and held in place with a thumb screw.

The visual position indicator (yellow pointer) is calibrated by rotating it about a shaft. Its posi-tion is held by friction from tightening a set screw and is pre-positioned by Ariel during assembly. If the pointer indicates more than 100% at full load or less than minimum at star-tup, then it must be readjusted.

FIGURE 5-5: SLIDE VALVE AXIAL POSITION INDICATOR TRANSDUCER

Cross Section - Cover in Place

M16 or 3/8 “ NPT

Front View - Case Cover RemovedDouble Cam

Mounting BoltYellow Position Pointer

Cover Bolt

Do Not Use a Mounting Gasket between Case and Cylinder Cover

Single Cam

Precision Potentiometer

PAGE 5 - 8 3/02

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

If the potentiometer or cams are used to electronically stop slide valve travel, calibration is very important at minimum and maximum travel. The last few percent of travel to the full load position have a dramatic affect upon compressor flow and horsepower.

FIGURE 5-6: SLIDE VALVE AXIAL POSITION INDICATOR TRANSDUCER - WIRING DIAGRAM

FIGURE 5-7: POSITION INDICATOR - PRECISION WIRE-WOUND POTENTIOMETER

CWR

3

21

21345678910

5432111111

2 2 2 2 2

100%0%

Cams

------ Factory Set ------

Cams

------------ Adjustable by User ---------------

Electrical Connections

Precision Potentiometer

1 kS

3/02 PAGE 5 - 9

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Externally Changeable Slide Valve

Slide Valve Volume Ratio (Vi) Change - Externally Changeable Vi

The slide valve external spacer may be changed or eliminated to adjust for a different vol-ume ratio (Vi) that is appropriate for current operating conditions. Refer to Table 5-4 on Page 5-11 for spacer thickness values.

FIGURE 5-8: POSITION INDICATOR TRANSDUCER - CAM ADJUSTMENT

TABLE 5-3: POSITION INDICATOR - PRECISION WIRE-WOUND SINGLE TURN POTENTIOMETER

TECHNICAL DATA

Nominal Resistance 1 kS (0° TO 330°)

Resistance Tolerance + 5%

Resolution 0.079%

Power Rating 5 W / 40°C

Maximum Wiper Current in Malfunction 100 mA

Protection IP 50

Full Load Position (Maximum Position) 100% = 330° = 1 kS

Starting Position (Minimum Position - Externally Changeable) 20% = 114° = 344S

Starting Position (Minimum Position - Internally Changeable) 0% = 60° = 180 S

Single Cam

Hole for Thumbscrew to Secure Wrench Inside of Case

Cam Adjustment Wrench - Ariel Part Number 000550

Double Cam

Reverse Wrench to Adjust Opposite Side

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

TABLE 5-4: SPACER THICKNESS - EXTERNALLY CHANGEABLE Vi Slide Valve

COMPRESSORMODEL

SPACER THICKNESS FOR ADJUSTING VOLUME RATIO (Vi)

4.8 Vi 3.5 Vi 2.6 Vi 2.2 Vi

INCHES (cm) INCHES (cm) INCHES (cm) INCHES (cm)

AR166

No Spacer Required for 4.8 Vi

0.802 (2.04) 1.812 (4.60) 2.544 (6.46)

AR208 1.000 (2.54) 2.270 (5.77) 3.190 (8.10)

AR260K 0.972 (2.47) 2.150 (5.46) 3.000 (7.62)

AR260 1.260 (3.20) 2.840 (7.21) 3.907 (9.92)

FIGURE 5-9: HAND WHEEL EXTERNALLY CHANGEABLE SLIDE VALVE 100% POSITION - TYPICAL

FIGURE 5-10: HYDRAULIC EXTERNALLY CHANGEABLE SLIDE VALVE 100% POSITION - TYPICAL

Balance Oil Connection

Balance Piston

Balance Cylinder

Locating Dowel

Lockwasher & Nut

Oil Drain Plug

Cylinder Mounting Bolts

Vi Spacer

Oil Drain Plug

Slide Valve

20% Position Stop

Crank Handle

Hand Wheel

Axial Positioner Indicator

Hydraulic Oil Connection

Positioner Piston

Hydraulic Cylinder

Locating Dowel

Lockwasher & Nut

Oil Drain Plug

Cylinder Mounting Bolts

Vi Spacer

Oil Drain Plug

Slide Valve

20% Position Stop

3/02 PAGE 5 - 11

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Vi Spacer Adjustments - Externally Changeable Vi

The slide valve volume ratio (Vi) can be varied, by changing or eliminating the spacer, bolts and dowel pin, with the compressor stopped and depressurized. Determine the Vi required and secure the appropriate items from the toolbox or rebuild kit components, including spacer, mounting bolts, dowel pin, o-ring, along with required hand tools.

To replace the Vi spacer, be sure the compressor is properly vented and that the equipment is locked out so rotors can not turn. On hand wheel controlled units, remove oil balance tub-ing and drain plug to bleed cylinder oil that restricts axial piston movement. On hydraulically controlled units, open oil control valves and drain plug to bleed cylinder oil, if oil lines and electrical conduit lines are not flexible they will have to be removed. Remove locating dowel pin from cylinder mounting flange using threaded 10mm slide hammer adapter. Insert Ariel supplied jackbolts, which supports Vi spacer, then loosen and remove cylinder mounting bolts. Remove Vi spacer by moving cylinder axially with jackbolts, and backing them off.

Clean cylinder and compressor mating flanges and coat with Never Seez. Install or omit the proper spacer to achieve the required Vi; support spacer and adjust opening space with jack bolts. Install correct length mounting bolts and locate cylinder to compressor by installing appropriate length dowel pin. Tighten capscrews to the proper torque value as shown in Table 1-4 on page 1-10. Remove jacking bolts and lifting tools as required and replace thread protection plugs or grease.

Reattach or re-tube oil lines and/or conduit, and re-install drain plugs as required.

Stamp or vibra-etch the new volume ratio (Vi) and date on the volume ratio change plate. See Figure 1-7: on page 1-8 for plate location.

Move the slide valve through its entire range of travel. See Table 1-2 on page 1-7 for hand wheel controlled slide valve travel distance details.

Slide Valve Inspection/Replacement - Externally Change-able Vi

The slide valve may be removed for inspection, but its removal is not required to change the volume ratio (Vi). If the slide valve volume ratio (Vi) is also to be adjusted by changing or eliminating the spacer, see “Vi Spacer Adjustments - Externally Changeable V i” above for details.

RemovalTo remove the slide valve, position the slide valve to the 100% axial position. The male rotor must be rotated so that the shaft keyway is at the top (12 o’clock position), which positions rotor mesh for ease of slide valve cylinder removal and installation. Be sure the compressor is properly vented and that the equipment is locked out so rotors can not turn. Remove the oil line(s) and/or drain plug from the slide valve cylinder, and remove rotor housing drain plug to drain residual oil. Replace drain plugs when oil stops running. For hydraulically con-

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

trolled units, also unbolt slide valve indicator or remove electrical connection, as required, to allow for slide valve cylinder removal.

The slide valve cylinder is precision located to the compressor housing using a dowel pin. Without removing the dowel pin, insert jack screws to support the Vi spacer, if there is one and remove cylinder mounting bolts (capscrews). The control cylinder with the slide valve is removed using the jack bolts provided. Slinging parts to an overhead crane may be useful to assist removal. See Table 5-5 and Table 5-6 for approximate weights of components. Remove control cylinder o-ring and discard.

Inspect slide valve and replace as required.

ReplacementWith the slide valve at an 80% axial position, hold piston rod with a strap wrench to prevent shearing the positioning dowel and remove slide valve nut and lockwasher. Remove slide valve from the piston rod. Clean parts, being careful to remove Loctite residue from piston rod and nut threads.

Reassemble slide valve to piston rod with locating dowel properly aligned with the slide valve groove. Apply Loctite 222 (purple) to the first two piston rod threads and install lock-washer and nut. Hold the piston rod with a strap wrench and tighten nut to the proper torque value in Table 1-4 on page 1-10. Install new o-ring lubricated with a high viscosity silicone fluid such as Parker Super-O-Lube or equal.

Slide Valve Cylinder Assembly Into CompressorInsert slide valve cylinder with attached slide valve into the compressor, being careful to level the assembly while lifting piston rod/slide valve to put the slide valve on slide guide. With the Vi spacer supported on the jack bolts when applicable, reinstall the cylinder flange onto the dowel. Insert and tighten capscrews to the proper torque in Table 1-4 on page 1-10. Remove jack bolts and lifting tools as required; replace thread protection plugs or grease.

Reattach oil line(s), drain plug(s) and position indicator as required.

Move the slide valve through its entire range of travel. See Table 1-2 on page 1-7 for hand wheel controlled slide valve travel distance details.

TABLE 5-5: HAND WHEEL CYLINDER CONTROLLED SLIDE VALVE - APPROXIMATE WEIGHTS

MODEL

SLIDE VALVE ONLY (EXTERNALLY CHANGEABLE)

SLIDE VALVE, HAND WHEEL & CYLINDER

LB (kg) LB (kg)

AR166 19 (8.6) 80 (36)

AR208 40 (18) 160 (73)

AR260K 72 (33) 220 (100)

AR260 82 (37) 250 (114)

3/02 PAGE 5 - 13

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Oil Pump and Geared Tooth Coupling

Oil Pump ReplacementTo replace the oil pump, first mark the pump suction and discharge end connections, then remove oil piping from the pump as required. To remove pump from compressor, remove capscrews (or stud-nuts) and slide pump out, separating the coupling halves at the sleeve. The coupling driven-half will come out attached to the pump shaft, while the coupling sleeve is retained by the drive half of the coupling which is bolted and dowelled to the female rotor. Remove o-ring and discard.

NOTE: ON THE AR166, WHERE THE ADAPTER COVER PLATE DOES NOT HAVE ITS OWN BOLTING (i.e. HELD IN PLACE BY THE PUMP BOLTING), REMOVE THE ADAPTER AND DISCARD O-RING.

Adapter cover plates which have separate bolting need not be removed. Loosen the key set screw and remove gear coupling-half from the pump shaft with a two or three jaw gear puller. Inspect the coupling’s geared teeth, if there is excessive wear, replace the entire cou-pling with a new assembly.

Replace the pump with a new part, correct for the compressor application. Install the cou-pling driven-half to the new pump shaft with key installed and firmly seated. There should be a slight clearance of 0.005 in. (0.13mm) between the top of the key and the mating coupling. Position the coupling-half on the pump shaft end so the axial spacing between the coupling halves is 3/32 in. (2.5mm), then tighten set screw, see Figure 5-11: on Page 5-15.

NOTE: FOR THE AR166 & AR260 THE COUPLING DRIVEN-HALF SHOULD BE APPROXIMATELY FLUSH WITH THE PUMP SHAFT END. FOR THE AR208, THE COUPLING DRIVEN HALF EXTENDS BEYOND THE SHAFT END BY ABOUT 13/32 IN. (10mm).

Replace o-ring(s) with new parts. Lubricate adapter cover plate bore and coupling sleeve teeth with clean oil. Slide the pump into place, with shaft position rotated to properly engage gear teeth. Be sure pump flow is in the correct direction. Replace fasteners and tighten to the proper torque shown in Table 1-4 on page 1-10. Pour a small quantity of oil into pump intake and re-attach oil piping as required.

TABLE 5-6: HYDRAULICALLY CONTROLLED SLIDE VALVE - APPROXIMATE WEIGHTS

MODEL

SLIDE VALVE ONLY(EXTERNALLY CHANGEABLE)

SLIDE VALVE & CONTROL POSITIONER CYLINDER

LB (kg) LB (kg)

AR166 19 (8.6) 75 (34)

AR208 40 (18) 155 (70)

AR260K 72 (33) 215 (98)

AR260 82 (37) 245 (111)

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Coupling ReplacementTo replace the entire pump coupling, begin as described in first paragraph under Oil Pump Replacement above. Remove the fasteners as required, adapter cover plate and o-ring. Dis-card the o-ring. Remove the drive coupling-half socket head cap screw. Remove the drive coupling-half and sleeve assembly, being careful not to cock the coupling half and break the hardened dowel pins. Replace coupling drive half and sleeve with new parts. Position cou-pling drive-half, with sleeve installed, over dowel pins and draw up by tightening the cap screw to the proper torque shown in Table 1-3 on page 1-10. Verify the sleeve is free to pivot on the drive coupling-half gear teeth. Lubricate rotor housing bore with clean oil and install adapter cover plate, with a new o-ring. Replace fasteners and tighten to proper torque shown in Table 1-4 on page 1-10. Position new coupling driven-half on the end of the pump shaft and proceed with oil pump re-installation in “Oil Pump Replacement” above.

FIGURE 5-11: OIL PUMP AND COUPLING - TYPICAL

Oil

Pump

O-Ring

Cover Plate - Adapter

Dowel

Socket Head Capscrew

Set Screw & Key

Coupling Sleeve

Coupling Driven Half

Fasteners

Female Rotor

Male Rotor

Coupling Drive Half

B

A

“A” - “B” = 3/32 in. (2.5mm)

Approximately

13/32” (10mm)

AR208 Only

3/02 PAGE 5 - 15

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FOR MODELS: AR-166, AR-208, AR-260K & AR-260 SECTION 5 - MAINTENANCE

Ethylene Glycol Contamination

Ethylene glycol contamination of a compressor can result from a water-cooled oil cooler leak.

Ethylene glycol anti-freeze coolant mixture leaking into the oil can cause bearing damage and rotor seizure due to lack of adequate lubrication. The oil should be changed as recom-mended in Section 6, while being routinely sampled and analyzed by a qualified laboratory to verify suitability for continued use, including checking for ethylene glycol contamination.

If contamination is found, find and fix coolant leak. Even small quantities of ethylene glycol in the oil can be detrimental. If contamination is less than 5%, drain oil, replace filters and flush oil system, including all piping, with a 50-50 mixture of butoxyethanol (Dow Chemical Co. Dowanol EB or equal) and 10W oil using a motor driven pump. Flushing should be done on a warm compressor. Bearings should be continuously flushed for 1/2 hour while barring over compressor. All surfaces that come in contact with the oil are to be flushed which includes spraying all interior surfaces in the compressor and gas/oil separator/coalescing filter. Com-pletely drain cleaning mixture, being sure to drain all components of the oil system. Repeat flushing operating using a 60/40 mixture of 10W oil and kerosene or fuel oil. Completely drain oil system, install new filters and fill with proper oil.

If sampling indicates that glycol contamination is greater than 5% or compressor has seized due to contamination, the unit is to be returned to Ariel, torn down, cleaned with 100% butox-yethanol, flushed with kerosene or fuel oil and repaired as required. All surfaces that come in contact with oil must be cleaned with butoxyethanol, including all passages and piping, and then flushed with kerosene or fuel oil. Oil and filters must be changed. Coolant leak is to be found and repaired.

Butoxyethanol presents health and safety hazards. Use proper eye and skin protection and adequate ventilation. Do not use near open flame or sparks. See manufacturer's Material Safety Data Sheet for complete details.

Ethylene glycol, butoxyethanol, contaminated oils and solvents must be properly disposed. A chemical disposal service should be used.

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Mineral deposit build-up can occur when liquids have not been completely removed from the gas stream, particularly in low pressure natural gas applications. These minerals (such as salt and calcium dissolved in water saturated process gas) plate out when water flashes off due to pressure drop or heat. The minerals can build up on the suction strainer screen and in the compressor. If mineral build-up is observed during maintenance, additional steps should be taken for liquid removal from the gas stream prior to entering the compressor.

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SECTION 6 - TECHNICAL ASSISTANCE

Recommended Maintenance Intervals

Like all equipment, Ariel compressors do require maintenance. The frequency of mainte-nance is dictated by the environment in which the compressor is placed, the loads the user imposes on the compressor and the cleanliness of the gas.

First and foremost on the preventative maintenance list is the completion and compliance with the Ariel Corporation Packagers Standard and Compressor Start Up Check List. All items must be adhered to, both before and after start up.

The following is a guide only and, as stated above, may vary due to operating conditions. The time intervals start with the start up date of the unit. If your oil supplier's recommend oil service changes are more frequent than the Ariel recommendations, the supplier’s intervals should be followed. Regular oil analysis is recommended. If problems develop the oil should be changed immediately and the cause of the problem determined and corrected.

A log book should be kept with each unit. Every maintenance item can be entered with exacting detail in order that records will be available for tracking maintenance costs per unit and for trouble-shooting.

Operator logs should be reviewed by qualified personnel to determine trends in compressor performance and/or maintenance.

Daily1. Check oil pressures and temperature. Recommended compressor inlet oil tem-

perature is 150°F (65°C).2. Check gas/oil separator oil level when compressor is in operation. It should be in

mid-sight glass and, if not, determine and correct cause. Do not overfill.3. Check seal vent for blowing or excessive leakage. If blowing or leaking, deter-

mine cause and, if necessary, replace mechanical seal parts.4. Check and correct any gas leaks.5. Check and correct any oil leaks.6. Check operating pressure and temperatures. If not normal, determine cause of

abnormality. It is recommended that a daily log of operating temperatures and pressure be kept for reference. See typical log sheet on page 3-6.

7. Check shutdown set points. High-low pressure shutdowns set as close as prac-tical to current operating conditions.

8. Check for unusual noises or vibrations.9. Check gas/oil separator scavenged oil flow indicator for oil and entrained gas

flow. Adjust as required.

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10. Check oil filters differential pressures.11. Check slide valve position. Adjust as required.12. Check counter thrust gas balance pressure. Adjust as required.13. Check gas suction strainer differential pressure.

Monthly (in addition to Daily Requirements)1. Check and confirm safety shutdown functions.2. Adjust counter-thrust gas balance pressure for current operating conditions.3. Review oil analysis to determine if good for continued use.4. Inspect anchor bolts and shims for looseness. Tighten as required.

Every 6 Months or 4,000 Hours (plus Daily/Monthly)1. Check oil viscosity requirements for current gas analysis and operating condi-

tions.2. Change oil filters or before differential pressure exceeds collapse pressure, or

as specified by the manufacturer or oil consultant.3. Verify that oil is suitable for continued use. A more frequent oil change interval

may be required if operating in an extremely dirty environment or if the oil sup-plier recommends it or if an oil analysis dictates it. A less frequent oil change interval may be required If the oil is replenished on a regular basis due to usage.

4. Clean strainers - oil and gas.5. Re-tighten hold down stud-nuts to proper torque values and perform a soft foot

check. More than 0.002 inch (0.05 mm) pull down requires re-shimming.6. Inspect coupling discs for cracking and/or axial distortion. Realign if necessary

to hold coupling alignment within 0.002 inches (0.05 mm) TIR.

Yearly or every 8,000 Hours (plus Daily/Monthly/6 Months)1. Inspect compressor mounting for twist or bending by checking shimming of com-

pressor feet.2. Check and re-calibrate all temperature and pressure gauges.3. Change gas/oil separator filter element or before differential pressure exceeds

collapse pressure, or as specified by the manufacturer or oil consultant.

Trouble Shooting

Minor problems can be expected during the routine operation of an Ariel compressor. These troubles are most often traced to liquid, dirt, improper alignment adjustment or to operating personnel being unfamiliar with Ariel compressors. Difficulties of this type can usually be corrected by cleaning, proper alignment adjustment, elimination of an adverse condition, replacement of a relatively minor part or proper training of the operating personnel.

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Major problems can usually be traced to long periods of operation with unsuitable lubrica-tion, improper counter-thrust gas balance pressure, careless operation, lack of routine main-tenance or the use of the compressor for purposes for which it was not intended.

Recording of the pressures and temperatures is valuable because any variation, when oper-ating at a given load point, indicates trouble.

While it would be impossible to compile a complete list of every possible problem, listed below are some of the more common ones with their possible causes.

Problem Possible Causes

ow Oil Pressure Driven coupling-half loose on pump shaft (coupling disengaged).Defective pressure gauge.Oil regulating valves improperly adjusted for conditions.Dirty or plugged oil strainer.Dirty oil filter.Improper low oil pressure switch setting.Low oil viscosity.Excessive leakage at seals or bearings.Leaking oil pump check valve.Oil pump wear.Improper end clearance in oil pump.

igh Oil Pressure Cold oil.Oil regulating valves improperly adjusted for conditions.High oil viscosity.Oil temperature too low.

ow Oil Temperature Thermostatic valve element defective.Oil heater or thermostat defective.

igh Oil Temperature Thermostatic valve element defective.Cooler fan not working.Oil cooler dirty.Low oil viscosity.

igh Gas Discharge emperature

Inadequate rotor injection oil rate.Plugged oil strainer.High oil temperatureHigh suction temperature.High suction or discharge pressure.

xcessive Vibration and/or oise in Compressor

Loose compressor hold down bolting.Coupling not properly aligned.Improper lube oil and/or insufficient lube rate.Lubrication failure.Liquids in gas.Excessive rotor end play.Loose or worn bearings.

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igh Oil Consumption Oil system over filled.Separator-scavenged oil line plugged or throttling valve closed.Excessive oil dilution from process gas.Collapsed coalescing filter element.Oil/ gas separator coalescing filter gaskets not sealed or defective.Improper coalescing filter element installed.

il Leakage at Slide Valve xial Position Indicator Case ounting

Position indicator drive rod seal damaged. Contact Ariel for replacement.

xcessive Leakage at echanical Seal Weep Tube

Mechanical seal is not effective and should be replaced.

xial Position Indicator Off at % (unloaded) and 100% (full ad) positions

Yellow pointer friction loose; adjust pointer and tighten set screw.Indicator case shaft improperly re-installed on the slide valve indicator rod or shaft coupling setscrews inside of case are loose; remove case, position the slide valve and yellow pointer to the minimum unloaded position (0% internally changeable or 20% externally changeable cylinders) and re-install. If coupling is loose, contact your packager or Ariel.

ompressor Flow Does Not atch Performance Predic-

on at Full Load

Verify that the Vi used in calculations matches the Vi installed in compres-sor.The axial position indicator may be improperly adjusted.Slide valve not at 100% position; adjust or calibrate yellow pointer, cams or potentiometer as required.Performance calculation input data incorrect; verify accurate gas analysis, rotating speed, suction pressure or temperature readings used. Perfor-mance prediction is based upon compressor suction and discharge flange conditions.Verify any compressor bypass valve(s) fully closed and not leaking.Verify suction gas strainer clean and intact.

Problem Possible Causes

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SECTION 7 - APPENDICESAriel Tools

Ariel Furnished ToolsAriel provides one tool box with each unit with customized tools included in the box as listed below (see Figure 7-1: and Figure 7-2: and Figure 7-3:).

Ariel provides these tools at no additional charge. Please contact your Distributor if you do not have these tools.

These tools are specifically designed for use on Ariel units. Clean all tools before use. Ensure that the tool and the part being removed or installed are fully engaged during the process. If a tool is missing, worn or broken, please call your distributor for a replacement. Do not use substitute, worn or broken tools.

BLE 7-1: ARIEL FURNISHED TOOLS

TOOL DESCRIPTIONPART NUMBER OR SIZE

QTY AR166 AR208 AR260K, AR260

Toolbox 1 A-0798

panner Wrench - Mechanical Seal Locknut 1 000531 000512 000012

Jack Bolt (12 Point Capscrew) - Removing Mechanical Seal Housing, class 12.9

2 M12x1.75x40mmM16x2x50mm

M16x2x50mm

Mechanical Seal Installation Tool 1 000608 000652 000653

am Adjusting Wrench - (Hydraulic Only) Slide Valve Axial Position Indicator Transducer

1000550

Allen Wrench - Axial Position Indicator Bolts 1 4mm

orged Steel Eye Bolt - Lifting Compressora

a. See Table 1-1 on page 1-5 for compressor weights; and Figure 1-7: on page 1-8 for lifting location connections.

23/4”-10x

23/4”-10x

23/4”-10x

2

Jack Bolt (12 Point Capscrew) - Removing Slide Valve Control Cylinder, class 12.9

2 M12x1.75x60mm M12x1.75x60mmM16x2x80mm

ocket Head Capscrew - Replacement Bolt for Axial Position Indicator, class 12.9

1M5 x 0.8 x 35mm

Bolting - Tightening Torque Charts 1 D-2159

pacers for Externally Changeable Slide Valve nly (with cylinder mounting bolts, dowel pin, label and label screws for each Vi setting)

1 each

3.5 Vi, 2.6 Vi & 2.2 Vib

See Figure 7-2:

b. One spacer may be installed in compressor as ordered. The Vi ratio is stamped on each shim-spacer. For 4.8 Vi, the

spacer is omitted. See Table 5-4 on page 5-11 for spacer thicknesses vs. compressor model and Vi.

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FIGURE 7-1: SPANNER WRENCH FOR MECHANICAL SEAL LOCKNUT - TYPICAL

FIGURE 7-2: Vi SPACER FOR EXTERNALLY CHANGEABLE SLIDE VALVE ONLY - TYPICAL

FIGURE 7-3: MECHANICAL SEAL CARTRIDGE INSTALLATION TOOL

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Minimum Hand Tools Required

The following hand tools are normally all that is required to work on Ariel compressors. These are in addition to the Ariel furnished tools listed in Table 7-1. Please contact Ariel if you have questions about tools on Ariel units.

• 1/2" Square Drive Ratchet Wrench• 2" and 6" Extensions for above Ratchet• 1/2" Square Drive Breaker Bar• 1/2" Drive Speed Wrench• 1/2" Female x 3/4" Male Adaptors• 1/2" Square Drive Universal Joint• 3/8" Square Drive Torque Wrenches (10 LB-IN to 250 LB-IN)• 1/2" Square Drive Torque Wrenches (15 LB-FT to 250 LB-FT)• 3/4" Square Drive Torque Wrench (to 1590 LB-FT)• 7/16", 1/2", 9/16", 3/4", and 15/16" Sockets for a 1/2" Square Drive Ratchet Wrench• 1/2" Hex Key and 1/4" Hex Key (Allen) Sockets for a Square Drive Ratchet Wrench• 5/16" - 12 Point Box Wrench• 1/2" x 9/16" Open End Wrench• 3/8" x 7/16" Open End Wrench• 7/8" x 15/16" Open End Wrench• 2 - Medium Size Screw Drivers• Slugging Hammer• Set of 3/8" Drive, 12 Point Sockets• Set of Inch 1/2" Drive, 12 Point Sockets• Set of Metric 1/2" Drive, 12 Point Sockets• 3/8" Square Drive Ratchet Wrench• 7/8", 1", 1-1/8", 1-3/8", M20, M24 and M27, 3/4" Drive, 12 Point Sockets• 1-5/16" and 1-1/2", 3/4" Drive, Sockets• 3/4" Square Drive Ratchet Wrench• 3/4" Female to 1" Male Adaptor• Strap Wrench• Slide Hammer (to remove dowel pins)

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Terms, Abbreviations1 and Conversion to SI Metric2

Area

in2 or square inch x 0.00064516 = meter2, or m2

in2 or square inch x 6.4516 = centimeter2, or cm2

Flow - Gas3

MMSCFD or million standard cubic feet per day x 0.310 = normal meter3/second, or m3/sn

SCFM or standard cubic feet per minute x 1.607 = normal meter3/hour, or m3/hn

Flow - Liquid

GPM or US gallons per minute x 0.0630902 = liter/second, or L/s = dm3/s

GPM or US gallons per minute x 0.227125 = meter3/hour, or m3/h

Forcelbf or pound (force) x 4.44822 = Newton, or N

HeatBTU or British Thermal Units x 1.05506 = kilojoule, or kJ

Lengthin. or " or inches x 25.4000 = millimeters, or mm

ft. or feet x 0.304800 = meter, or m

Masslb. or pound (mass) x 0.453592 = kilogram, or kg

1. US units of measure can appear abbreviated in upper or lower case.2. Maintain upper and lower case letters in SI Metric as shown.3. US standard is based on 14.696 psia & 60°F; Metric normal is based on 1.01325 bar & 0°C.

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Moment or Torque

LB x FT or pound-foot (force) x 1.35583 = Newton-meter, or N. m

LB x IN or pound-inch (force) x 0.112985 = Newton-meter, or N. m

Power1

HP or Horsepower x 0.745700 = kilowatt, or kW

Pressure2 or StressPSI or Pounds per Square Inch x 6.89476 = kiloPascal, or kPa

PSI or Pounds per Square Inch x 6894.76 = Pascal, or Pa

PSI or Pounds per Square Inch x 0.0689476 = bar

bar x 100 000 = Pascal, or Pa

bar x 100 = kiloPascal, or kPa

bar x 14.50377 = PSI, or Pounds per Square Inch

SpeedFPM or feet per minute x 0.005080 = meter per second, or m/s

RPM or r/min or revolutions per minute ÷ 60 = revolutions per second, or rev/s

Temperature°F or degrees Fahrenheit. (°F - 32)/1.8 = degrees Celsius, or °C

Timesec = second, or s

min or minute x 60 = second, or s

hr. or h or hour x 3600 = second, or s

1. Horsepower based on 550 ft-lb/sec2. G suffix PSIG (barg) indicates gauge pressure, PSIA (bara) indicates absolute and PSID (bard) indicates dif-

ferential.

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Viscosity

SSU, SUS or Sailboat Universal seconds x 0.22 - (180/SSU) = mm2/s = scientist, or cSt

(for a range of 33 thru 200,000 SUS)

Volumegal or gallons (US liquid) x 3.78541 = liter, or L

Other AbbreviationsS = Ohm = V/A = Volt ÷ Ampere = Electrical Resistance

A = Ampere = Electrical Current

ANSI = American National Standards Institute

bara = Absolute Pressure

bard = Differential Pressure

barg = Gauge Pressure

CI = Cast Iron

CL. = Clearance

CU = Cubic

CW = Clockwise

CCW = Counter Clockwise

6 = Centering

DIN = German Standards Institute

INJ = Injection

k = Ratio of Specific Heats

k = kilo, see Table 7-3

L/D Ratio = Length of male rotor divided by its diameter

MAX. = Maximum

MIN. = Minimum

N/A = Not Applicable

NO. = Number

NPT = National Pipe Thread

Pd = Discharge Pressure

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Ps = Suction Pressure

% = Percent

QTY = Quantity

SG = Specific Gravity

SI = International System, as applied to the modern metric system

S. N. or S/N = Serial Number

THD = Thread

TIR = Total Indicator Reading

TPI = Threads per Inch

UNC = Unified (Inch) National Coarse Screw Threads

UNF = Unified (Inch) National Fine Screw Threads

Vi = Volume Ratio = Volume of gas, in actual volume, at point where compression begins,

divided by volume of gas, in actual volume, at end of compression ( )

V = Volts = Electrical Potential

W = Watt = Power

W/ = With

Vi

Vs

Vd------=

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Gas Analysis Common Abbreviations

TABLE 7-2: GAS ANALYSIS COMMON ABBREVIATIONS

COMMON ABBREVIATION COMPONENT NAME (SYNONYM)

CHEMICALFORMULA

C1 Methane CH4

C2 Ethane C2H6

C3 Propane C3H8

IC4 Iso-Butane (2-Methyl Propane) C4H10

NC4 N-Butane C4H10

IC5 Iso-Pentane (2-Methyl Butane) C5H12

NC5 N-Pentane C5H12

NEOC5 Neopentane C5H12

NC6 Hexane C6H14

NC7 Heptane C7H16

NC8 Octane C8H18

NC9 Nonane C9H20

NC10 N-Decane C10H22

NC11 N-Undecane (Hendecane) C11H24

NC12 N-Dodecane C12H26

C2- Ethylene (Ethene) C2H4

C3- Propene (Propylene) C3H6

BENZ Benzene C6H6

TOL Toluene C7H8

EBNZ Ethylbenzene C8H10

CO Carbon Monoxide CO

CO2 Carbon Dioxide CO2

H2S Hydrogen Sulfide H2S

H2 Hydrogen H2

O2 Oxygen O2

N2 Nitrogen N2

H20 Water H20

He Helium He

Ar Argon Ar

--- Air ---

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Metric Factors

Technical and Service Schools on Ariel Compressors

Ariel schedules several in plant schools each year, which include classroom and hands on training. Ariel can also arrange to send a representative to provide a customized training school at your location. Contact Ariel for details.

Ariel Customer Technical Bulletins (Formerly Ariel News-letters)

Ariel Customer Technical Bulletins provide important technical information including changes, corrections and/or additions to the Technical Manual for Packagers and End Users. Be sure to refer to this material before operating or servicing the equipment.

A complete listing of these Bulletins is available at the Ariel Website, and copies may be obtained from the Packager or from Ariel.

Vendor Literature

When available, vendor literature on purchased parts used in Ariel Compressors is provided on the Ariel Website (www.arielcorp.com), or copies may be obtained from the Packager or from Ariel.

TABLE 7-3: USEFUL SI METRIC MULTIPLE AND SUBMULTIPLE FACTORS

MULTIPLICATION FACTOR PREFIX SI SYMBOLa

a. Maintain upper and lower case letters as shown.

1 000 000= 106 mega M

1 000 = 103 kilo k

100 = 102 hectob

b. Not Recommended, but occasionally used.

h

10 = 101 dekab da

.1 = 10-1 decib d

.01 = 10-2 centib c

.001 = 10-3 milli m

.000 001 = 10-6 micro :

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Ariel Contact Information

• Ariel Response Center Technicians or Switchboard Operators will answer telephones during Ariel business hours, Eastern Time - USA or after hours by voice mail.

• The after Hours Telephone Emergency System works as follows:1. Follow automated instructions to Field Service Emergency Technical Assistance

or Spare Parts Emergency Service.2. Calls are answered by voice mail.3. Leave Message: caller’s name, telephone number, serial number of equipment

in question (frame, cylinder, unloader) and brief description of emergency.4. Your voice message is routed to an on-call representative, who will respond as

soon as possible.• Users must order all parts through Authorized Distributors.

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Ariel Response Center (ARC) 888-397-7766(toll free USA & Canada) or740-397-3602 (International)

740-397-1060 [email protected]

Spare Parts 740-393-5054 [email protected]

Order Entry 740-397-6450 ---

Ariel World Headquarters740-397-0311 740-397-3856

[email protected]

Technical Field Service [email protected]

Ariel Website: www. arielcorp.com

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