Mechanical Specification

HVAC CONSULTANT: Eng. ABDEL SALAM MAHROUS

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HEATING, VENTILATION AND AIR CONDITIONING

CHAPTER 1

GENERAL PROVISION

1. ORGANIZATION OF THE WORK:

1.1The work called for under this contract shall be carried on simultaneously with the work of

other trades in a manner such as not to delay the overall progress of the work. The HVAC

contractor, shall be prepared to furnish promptly to other trades involved at the project all

information and measurements relating to the work which they may require. He shall

cooperate with them in order to secure the harmony necessary in the interest of the project as

a whole.

1.2The HVAC contractor shall put his work in place as fast as possible to meet all

construction schedules.

1.3The HVAC contractor should keep at all times a competent superintendent in charge of the

work. Such superintendent shall be replaced if unsatisfactory to the owner.

1.4The HVAC contractor, should keep at all times a complete file of all contract and shop

drawings at the site and available for inspection by owner representatives. All installation and

equipment shop drawings shall be initialed and dated upon installation. This procedure will

serve to ensure proper scheduling and enable owner's representatives to check the work in

progress.

1.5Every facility shall be provided to permit inspection of the work by owner's representatives

during the course of construction.

1.6The HVAC contractor shall be responsible for his work until its completion and final

acceptance, and shall replace any of the same which may be damaged, lost or stolen, without

additional cost to the owner and party contracting for his services.

2. APPROVAL OF THE WORK:

2.1All workmanship, equipment and materials supplied under this contract shall be subject to

the acceptance of the owner and his representatives, who shall have the power to reject any

items which in their judgment are not in full compliance with the plans and specifications.

2.2Fifteen days following award of project drawings acceptance by the owner, the contractor

shall start submitting the required information pertaining to the equipment and materials he

will be furnishing, commencing with the list of manufacturers and following up in short order

with the shop drawings and other documents. The owner and his representatives reserve the

right to reject, as unacceptable; any items for which in their judgment they have not been

allowed adequate lead time in which to investigate suitability.

3. PERMITS, INSPECTIONS:

3.1All required permits and inspection certificates shall be obtained, paid for, and made

available at the completion of the work.


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3.2Any portion of the work, which is not subject to the approval of an authority having

jurisdiction, shall be governed by the applicable sections of the overall international codes and

specifications.

4 STANDARDS:

4.1Codes: All air conditioning work shall comply with current applicable local and

international codes and authorities having jurisdiction.

4.2 In addition to the requirements shown or specified, comply with the latest current

applicable standards, specifications or codes published by:

1. ASME American society of mechanical engineers.

2. ARI Air conditioning and refrigeration institute

3. ANSI American national standards institute.

4. ASHRAE American society of heating refrigerating and air

conditioning engineers.

5. ASTM American society for testing and materials

6. NFPA National fire protection association.

7 UL Underwriter's laboratories.

8 NEMA National electrical manufacturer's association.

9 SMACNA Sheet metal and HVAC contractor's national association.

10BS British standards

4.3Include all items of labor and material required to comply with such standards and codes in

accordance with Contract Documents. Where quantity sizes or other requirements indicated

on drawings or herein specified are in excess of the standard or code requirements, the

specifications and/or drawings shall govern.

4.4The HVAC drawings shall serve as working drawings for the general layout of the various

items of equipment. However, layout of equipment, accessories, specialties, ductwork, and

piping systems are diagrammatic unless specifically dimensioned, and do not necessarily

indicate every required valve, fitting, trap, duct, elbow, transition, turning vane ,or similar

items required for a complete installation .

5. QUALIFICATIONS:

5.1This specifications indicate the required standard of quality and characteristics of the

various products installation layouts based on these products as shown on the drawings.

5.2Equivalent products by other manufacturers may be substituted. If equivalents are

substituted, the contractor shall be responsible for all modifications that must be made to the

structural, architectural, electrical, mechanical and plumbing work to accommodate the

installation, and shall perform all work required to complete the installation at no additional

cost to the owner.

6 SUBMITTALS:

6.1 Shop drawings:

Submit to owner or his representative for review in accordance with the requirements of the

contract documents three copies detail dimensioned shop drawings as stipulated in the

sections of specification. These drawings shall be new drawings prepared by the contractor

and. In preparing shop drawings, establish lines and levels for the work specified and check

the drawings to avoid interference with structural features and other work. Immediately call to

the attention of owner or his representative any interference for clarification in writing. Shop


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drawings shall include floor layouts drawn to a minimum scale of 1:100 showing all

equipment, ductwork and piping ,and scale 1:50 and 1:25 for details .

6.2 Manufacturers' literature:

Manufacturers' literature and data sheet shall be submitted in three copies indicating the

necessary installation dimensions, weights, and materials and performance information. The

performance shall include capacities, rpm, HP, pressure drop, design and operating pressure,

temperatures, and similar data complete electrical data, including power conditions, electrical

diagrams shall be included.

7. GUARANTEE PERIOD:

7.1The contractor shall guarantee the material and workmanship for the required installations

and satisfactorily operation for twelve months from the date of final acceptance and taking

over without showing any defect due to any cause.

7.2 Repair work required because of failure of materials or workmanship within the guarantee

period will be completed without cost to the owner. All repair work required for defects

occurring beyond the guarantee period will be paid for by the owner.

8. SAMPLES:

Submit to owner or his representative two- (2) samples of each type of air outlet and any

material required by owner.

9. PROTECTION:

The contractor shall keep all pipe and duct openings closed by means of plugs or caps to

prevent the entrance of foreign matter, and cover all fixtures equipment and apparatus as

required to protect them against dirt, water, chemical or mechanical damage both before and

after installation. Any such fixtures, equipment or apparatus damaged prior to final

acceptance of the work shall be restored to its original condition or replaced by the contractor

and at his own cost.

10. PAINTING:

10.1Priming: All shop-fabricated and factory-built equipment not galvanized or protected by

plating, shall be cleaned and given one shop coat of paint primer, before delivery to the site.

Any portions of the shop coat damaged in delivery or during construction shall be located.

10.2Nameplates:Do not paint nameplates, labels, tags, stainless steel or chromium - plated

items such as valve stems, motor shafts, levers, handles, trim stripe, etc.

11. IDENTIFICATION:

After finish painting is completed, paint or stencil 1-1/2"(38 mm) high black-enamel block

type letters and/or numerals on all items of equipment for identification purposes.

Also paint or stencil a complete system of ductwork identification adjacent to each valve and

damper, branch take -off runs with flow arrows


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12. ELECTRICITY AND WATER:

The contractor shall be entitled to use such supplies of electricity and water as shall be

available on the site for the work and shall , at his own expense, provide any apparatus

necessary for such use .

13. PERIOD OF INSTALLATION:

Tenders shall state in their offers the time within which they shall install the required

equipment indicated in this tender, taking into consideration the installation program

provided by owner.

Renderers' are requested to give the shortest period possible for the installation. Length

of time shall be taken into consideration.

14. INSTRUCTION MANUALS:

Provide 3 copies in bound booklet form containing the following information

*Descriptive literature of equipment and components with manufacturer’s name, model

number, capacity rating and operating characteristics.

*Service manual prepared by manufacturer for every major piece of equipment giving

operating and maintenance instructions starting and shut - down instructions, lubrication

instructions and list of possible breakdown and repairs.

*Manufacturer’s list of general spare parts for every piece of equipment with unit prices.

*Manufacturer’s list of recommended spare parts for three year of operation of each piece of

equipment with unit prices.

*Detailed and simplified color coded as-installed wiring diagrams of motor controllers and

automatic controls with tag number, location and function of each instrument and electrical

device with description of sequence of operation and interlocks.

15. RECORD DRAWINGS:

Submit 3 sets of as-built drawings and electrical wiring diagrams

All as built diagrams shall be plasticized in a frame in machinery room.

16. Proposed HVAC system

1) Chilled water plant shall consist of :

*Two electrically driven air cooled screw chillers located on roof

the unit shall consist of two compressors, and two separate refrigerant circuits,

unit shall comprise microprocessor control center, flow switches and vibration isolators. Units

shall deliver chilled water to all building systems requiring this utility.

* Three chilled water pumps shall be provided including (one stand by). To deliver chilled

water to all air handling units and fan coil units

2) Fan coil units shall be properly located to direct flow of supply air to rooms. Units shall be

quiet-operating, and shall include three speed manually operated fan switch with on "off"

position, control system shall affect by on / off control valve, electric heaters shall be provided

for all F.C.U’s and air handling units, for heating purposes

.

3) Supply outlet for fan coil units and air handling units

4) Exhaust system shall be provided for toilets, also exhaust system shall be provided for

kitchen hoods with air quantities suitable to remove smoke and odors.


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5) Air handling units shall be installed to serve areas and shall supply conditioned air through

thermally insulated galvanized sheet metal ducts with air outlets to the required spaces

END OF CHAPTER

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CHAPTER 2

AIR COOLED CHILLER

1. GENERAL :

The contractor shall furnish and install microprocessor controlled air cooled liquid chillers

utilizing screw compressors and electronic expansion valves

.All units construction shall be designed to conform to ASHRAE 15 latest revision safety

standard , NEC (U.S.A.) and ASME applicable codes & ARI or equivalent European

standard and tolerances

All units shall be designed, manufactured and tested in facility with quality assurance system

certified ISO 9001,1994,

.Machine safety .electrical equipment in machines, general regulation to be in accordance to

EN 60204-1

Factory assembled , single piece , air cooled liquid chillers, contained within their unit

cabinets shall be all factory wiring , piping , controls ,refrigerant charge (R 134-a) , and

special features required prior to field start-up .

Capacities and characteristics shall be as per technical schedule .

2. EQUIPMENT :

Chases and Casing

Frame shall be made of U steal beam and protected by three layers of paint

The unit cabinet shall be galvanized steel , with polyester-powder paint finish, electro

statically applied and oven-baked before assembly and withstanding test accordance with

ASTM standard

•. Compressors

-Semi-hermetic twin-screw gear driven compressors with internal muffler and check valve.

Each compressor is equipped with a discharge shutoff valve.

Capacity control shall be provided by pilot- operated solenoid valve, capable of reducing unit

capacity to 20%

-Motor cooling shall be provided by direct liquid injection and protected by internal over load

thermistor

-Lube oil system shall include pre filter and internal filter

• Cooler

Shall be tested and stamped in accordance with European standard

Multi-tube evaporator with 2 independent refrigerant circuit, internally-enhanced, seamless

copper tubes ,expanded into tube sheets.

Evaporator shall have refrigerant level control, drain and vent valves

Thermal insulation of the shell and end covers using 19 mm closed-cell polyurethane.

Mechanically cleanable shell and tube type with removable heads


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• Condensers

-Pre coated aluminum fins mechanically bonded to copper tubes, with built in sub coolers.

-Condenser fan motor shall be 3 phase type with permanently lubricated and class F insulation

and protected by circuit breaker

-Ultra low-noise axial fans with blades and rotating shroud, made of recyclable composite

material

• Refrigerant Circuits

Each refrigerant circuit includes one compressor , oil separator ,replaceable core filter drier ,

combined moisture indicator and sight glass, discharge and liquid shutoff valves , expansion

valve and refrigerant economizer .

• Control Box ,Power and Control Wiring

Galvanized sheet steel, polyester paint finish , with hinged access doors, containing one

contactor and one set of fuses per compressor, control circuit transformer, 3-phase power

supply terminals. Inside of control box control circuit cables and electrical components

numbered .

• Oil Supply Solenoid Valve :

An oil supply solenoid valve is standard on the compressor to isolate the compressor from oil

flow when the compressor is not operating. The oil solenoid is field replaceable .

• Suction & Economizer Screens :

To increase the reliability of the compressor, a screen has been incorporated as a standard

feature into suction and economizer inlets of the compressor.

• Unloading System :

Screw compressor shall have an unloading system consisting of two steps of unloading that

decrease the compressor capacity by rerouting partially compressed gas back to suction .

•Head Pressure Control :

The unit shall be equipped with head pressure control system for controlling fans based on

saturated condensing temperature.

• Safeties & Control :

Unit shall be equipped with all necessary safeties and control system.

Unit control shall include as a minimum the microprocessor. the local/off/ remote/cnn

selector and 6 digit diagnostic display

Shall be capable of performing the following features:

-Automatic change-over, capacity control, limiting chilled water temperature,

-Control of leaving water temperature with return temperature compensation for control of

compressors and electronic expansion valves .

-Protection against abnormal operating conditions high or low refrigerant pressure,

- Protection against low suction temperature , insufficient chilled water flow ,compressor

reverse rotation ,low oil pressure ,voltage imbalance ,ground current thermal overload

,electrical overload ,loss of phase, etc


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-Control shall provide general alarm remote indication for each circuit

.Communication:

Unit controls include a 2-line ,24-character per line diagnostic display. Display module is

capable of displaying set points ,time ,system status ( including temperatures, pressures,

and percent loading ) ,and any alarms or alert conditions .Remote control: start/stop , dual

set point, adjustment ,demand limit control, general fault reporting by circuit .

Chillers have the following options and accessories

Pre coated for coil and fins

Protection grills

High and low pressure manometers

Compressor suction valve

Compressor and evaporator sound enclosure and condenser acoustic louver

Low nose fan

Compressor has electronic starter

Tropical zed control box

. Electrical characteristics

Unit with two compressors shall have a factory-installed, star delta starter to limit electrical

inrush current.

Control voltage shall be supplied by a factory installed transformer.

Unit shall be supplied with factory- installed, electrical disconnect switch/ circuit breaker.

END OF CHAPTER

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CHAPTER 3

CENTRIFUGAL WATER PUMPS

1. GENERAL

The contractor shall furnish and install as shown on the drawings as described in these

specifications single stage, split case centrifugal pumps each of the size and capacity shown in

the pump schedule.

2. DESCRIPTION AND MATERIAL

2.1 Impeller shall be bronze, cast in one piece, enclosed type statically and dynamically

balanced and keyed to the shaft and secured with a suitable locknut.

2.2 Shaft shall be of high- grade stainless steel.

2.3 mechanical seal: all pumps shall be provided with mechanical seals of flexible bellows

type it shall be suitable to with stand specified pump design pressure, springs shall be of

stainless steel and metal parts of seal head shall be non-rusting material

2.4 bearings shall be heavy duty ball bearings sealed For Life, sized to transmit highest loads

and pre-packed with high temperature grease.

2.5 pump working pressure shall be 150 PSI at the design water temperature

2.6 Impeller diameter shall be selected so that the design capacity of each pump shall not

exceed 80 % of the capacity obtainable with maximum impeller diameter at the design speed

for that model.

2.7 A replaceable shaft sleeve shall be furnished to cover the wetted area of the shaft under the

seal or packing.

2.8 The pump and motor shall be mounted on a common base plate of heavy structural

steel design with securely welded cross members and open grouting area.

2.9 A flexible coupler, capable of absorbing torsion vibration, shall be employed between the

pump and motor, and it shall be equipped with a suitable coupling guard as required.

2.10 motor sizes shall be selected completely non overloading over the entire performance

range of the particular pump.

Motor type shall be TEFC , with class F insulation

2.11 Pump casing shall be manufactured from close - grained cast iron machine to fine limits.

2.12 The pump shall be factory , thoroughly cleaned , and painted with one coat of

machinery enamel prior to shipment. A set of installation instructions shall be included with

the pump at the time of shipment.

END OF CHAPTER

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CHAPTER-4

FAN COIL UNITS

1-GENERAL

Provide fan coil units produced by a manufacturer listed as an acceptable manufacturer

Furnish and install factory assembled fan coil units of size, type, capacities and

arrangement indicated on drawing and specified herein.

Units shall be ARI certified ARI that capacities and size of each model is in compliance

with the industry standard 440-89. And sound in accordance with industry standard 443-

71 for sound rating of fan coil units

Any unit does not fulfill this requirement shall be replaced

2-COMPONANTS

2-1 UNIT CABINET

Basic unit shall include coil , sleeved coil end supports , main and auxiliary drain pan,

fan board , fan , fan housing, 3 speed motor

Units chassis and panels shall be made of heavy gauge galvanized steel. Lined on the

inside with 10mm thick closed cells fire retardant insulation

Filters shall be standard type .and shall be very easy to remove without tools and fixing

on sliding rails

2-2 COOLING COIL

Coils shall be seamless copper tubing mechanically expanded into high efficiency

corrugated aluminum fins, the coil shall has manual air vent. Coils shall be 3 rows

minimum.

Maximum working pressure 300 psig, factory burst test 450 psig

2-3 DRAIN PAN

Drain pans shall be made of galvanized steel. epoxy paint coated on both sides and

externally covered by closed cells insulation .the drain pan shall be sized to collect and

discharge condensate coming from coil ,headers and coil bends

2-4 FAN

Fan wheels centrifugal forward-curved, double width statically and dynamically balanced,

of aluminum alloy for quit operation Fan casing and inlet cones are made of galvanized

steel for long life operation .

2-5 MOTOR

Motor shall 3 speed , permanent split capacitor type of class F insulation All wiring is

made at 220V-50HZ ,three speed and have ,integral thermal overload protection. Motor

shall operate satisfactorily at 90 % of rated voltage on all speed settings and at 10 % over

voltage without undue magnetic noise.


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2-6 HEATER

Electric heater shall be finned armored type complete with contactor and with safety

thermostat and factory wired to the unit .

2-7 ROOM THERMOSTAT

Shall be calibrated and has cooler /warmer knob with degree readings and 3 speed /off fan

control switch

END OF CHAPTER

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CHAPTER 5

PIPE WORK AND FITTINGS

1. GENERAL:

Each part of the system of piping shall be complete in all details and provided with all

control valves and accessories necessary for satisfactory operation.

The tender drawings indicate generally the sizes and routing of all main piping

The contractor has to submit shop drawing showing details of all piping, locations ,anchors,

guides, expansion loops and hangers,

All piping shall be grouped wherever practical and shall be erected to present a neat

appearance. Pipes shall be parallel to each other and paralleled or at right angles to structural

members of the building and shall give maximum possible headroom.

All pipe drops shall be truly vertical, no joints shall be formed in thickness of walls, floors or

ceilings. The contractor is responsible for ascertaining from the owner the thickness of plaster

and other wall finishes, skirting heights, and floor finishes.

Pipe work shall generally be set around all columns and shall follow the contour of the

building whether so indicated on the drawings or not

Piping shall not pass in front of door - ways so that it is at least 15 cms. above finished floor

level and at least 2.5 cms from finished wall face. Sufficient space shall be allowed for

accessibility for servicing.

Piping shall be pitched for proper circulation and drainage.

Run outs shall be graded in such a manner as to prevent air traps being formed within them

when the mains expand or contract Automatic or open vents are to be provided at high points

and piped to suitable drains.

All drain piping shall be galvanized steel at roof and polypropylene inside building ,drain

pipes shall be pitch down in the direction of flow.

All low points of the system must be fitted with drain valves to permit the complete draining

of the system.

Bottoms of all risers must have dirt pockets the same size of the riser and at least 30 cms long

with a drain valve fitted.

Automatic and manual air vent valves are to be provided at high points and piped to suitable

drains.

All water piping to equipment and valves shall be connected with either flanges or unions for

dismantling and removal.

All piping shall be reamed after cutting to remove all burrs.

All piping installation shall be allowed the contraction and expansion of the pipes by means

of changing the pipe direction or using expansion joints

All reductions in sizes of piping in the direction of downward pitch shall be installed with

eccentric fittings to maintain a level bottom.

Approved pipe fittings shall be used and bending of pipes will not be allowed.

Bends showing kinks, wrinkles, or other malformations, will not be acceptable

Cutting of bends will not be permitted.


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Piping shall not be installed passing through ductwork or directly under electric light outlets

or extend beyond furring lines, as determined by the drawings.

In placing pipes through sleeves, near walls, partitions or in chases care must be taken to

provide sufficient space for pipe covering.

Where pipes are held by vises, as when screwing, care shall be taken to ensure that the pipe

surface is not damaged.

Any pipe work so damaged shall not be fitted.

All pipes stored on site shall be kept clear off the ground and where possible stored under

cover. Pipes corroded beyond normal " stock rust " condition shall not be used . Special care

should be taken to prevent dirt and foreign matter entering open ends of pipes during

erection.

All pipes shall have two coats of paint prior to installation and final coat after installation.

All pipe work, valves, fittings, etc., shall be as detailed for the various services in the

schedules forming part of this specification.

2. MATERIAL OF PIPING:

Service Material Type Specification standard

Chilled water Seamless steel Black Schedule 40

heavy

ASTM

A53,A120

Vent Seamless steel Black Schedule 40

heavy

ASTM

A53,A120

Drain Galvanized

/Polypropylene

heavy

3. MATERIAL OF PIPE FITTING:

Service Size Material Type Standard

chilled water 2" &below MI Screwed ANSI B16.11

chilled water 2.5"&above Steel Welding ANSI B16.9

Vent All MI Screwed ANSI B16.11

Drain All Screwed

4. PIPE SUPPORTS AND ANCHORS:

All supports for steel piping shall be ferrous. Brackets or supports shall be set out so that they

do not obstruct the access to valves, flanges or other fittings requiring maintenance.

0All pipe work shall be support by means of approved clips or hangers at centers as detailed .

In the event of two or more pipes being carried by a single support the spacing shall be for the

shorter interval.

All vertical drops shall be supported so as to prevent sagging or swinging . Unless otherwise

indicated, pipe hangers shall be spaced as follows :

Pipe size Max. hanger spacing Rod size

1” and smaller 6Ft 3/8”

1 1/4” to 4 9 Ft 1/2”

5” to 8” 12Ft 3/4”

10”and larger 20 Ft 1 1/2


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All hangers on pinning including clevis, hangers, inserts, clamps. Brackets shall be dipped in

zinc chromate primarily before installation. Rods shall be galvanized.

Hangers for pips up to 4 inch shall be adjustable wrought clevis, hangers for larger pipes shall

consists of two rods and cross rod with cust iron pipe rollers complete with adjustable sockets

and nuts.

Piping at all equipment valves shall be supported to prevent or distortions in the connected

equipment valves. Piping shall be supported to allow for removal of equipment valves and

accessories with a minimum of dismantling and without requiring additional supports after

these items are removed.

All channels, angles, plates, clamps, etc . necessary for the fastening hangers shall be

furnished by the contractor.

All hangers shall be properly sized for the pipe to be supported . Oversized hangers shall not

be permitted.

Details of hangers and supports to be used by the contractor shall be submitted to the

Engineer for approval before fitting.

All hangers shall be provided with lock nuts and have provisions for vertical adjustment of

pipes .

Paralle groups of pipes shall be supported by trapeze type hangers of steel construction.

Individual horizontal piping shall be supported by hangers consisting of malleable split rings

with malleable iron sockets , or steel clevis type hangers , or roller hangers where specified .

Vertical piping shall have heavy wrought iron or steel clamps securely bolted on the piping

with the end extensions bearing on the building construction.

Piping shall be anchored where required to localize expansion or to prevent undue strain on

piping and branches. Anchors shall be entirely separated from hangers and shall be heavy

forged or welded construction of approved design.

5. PIPE INSULATION PROTECTION SADDLES:

Insulation shields shall be used to protect the insulation on all pipes. Insulation protection

saddles shall be welded to insulated hot pipes at roller supports. Wherever fiberglass pipe

insulation is installed, alternative high density insulation of equal thickness shall be installed

in lieu thereof where hangers and insulation shields are installed. the insulation shields shall

bear only on an insulation material which is of such density that it will not compress , crush or

deform .

Saddles shall consist of 1.5 mm galvanized steel plate. Plate shall be curved to fit the contour

of the insulation and shall cover the lower surface.

Saddles shall be secured to insulation by means of steel bands.

6. PIPE SLEEVES:

All pipe opening through walls, partitions and slabs shall have sleeves having an internal

diameter at least 1" larger than the outside diameter of the pipe or of the insulation, for

insulated service.


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Pipes passing through masonry, concrete floors or concrete interior walls shall be provided

with sleeves of galvanized standard weight steel pipe flush with walls and ceilings and

extending 1" above finished floors .

Pipes passing through interior partitions shall be provided with sleeves of 22 gauge

galvanized sheet steel flush with finished wall surfaces .

7. FLASHING SLEEVES:

Flashing sleeves shall be provided where pipes pass through water- proof membranes

.Flashing sleeve details shall be submitted to the Engineer for approval but generally they

shall be provided with an integral flange set into the membrane. The associated pipe shall also

have a flange and shield which shall extend beyond the insert and be sealed with approved

mastic.

8. WELDING:

Where shown on drawings or specified or directed, welded joints, outlets and flanges shall be

used.

Care shall be taken to ensure that welding metal or flux does not project into the bore of the

pipe. All welds shall be of good clean metal free from slag and porosity, of even thickness

and contour, well fused with the parent metal, hammered on completion, and finished smooth.

The engineer reserves the right to have cut for examination 2 % of all welds made. The

contractor shall re-make the points at no extra charge.

All welded joints (except pipe welded end to end ) shall be made by use of forged one -

piece, welding flanges, caps, elbows , branch outlets and tees of approved make.

All such fittings, etc., shall be of a type which maintains full wall thickness at all points ,

ample radius fillets, and proper levels or shoulders at ends.

All job welding may be by electric welding or acetylene process.

Wherever welded piping connections to equipment, valves, or other units need maintenance,

servicing, or require possible removal, the connecting joint shall be by means of unions of

flanges. Pressure rating of flanges shall match the pressure rating of the flanges on the

equipment to which the pipe connects.

9. UNIONS:

Unions are required on pipe sizes 2" and under. Unions shall be ground taper joint type good

for 150 pi working pressure.

Unions shall have bronze conical seats ground in. Flat union shall not be used.

10. SCREWED JOINTS ON STEEL PIPING:

Screwed joints shall be clean threaded pulled up tightly and made with approved jointing

compound and long strand hemp.

After joints have been formed all surplus hemp shall be cut away and the joints wiped clean.

Where pipe galvanized care shall be taken to ensure that threads are carefully cut so that the

number of exposed threads is minimized.


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11. FLANGED JOINTS:

All flanged joints shall be flush and truly aligned and made with approved corrugated

rings, compressed asbestos on composition joints.

Flanges for connection to welded pipe shall be "slip on" or welding neck standard steel type

made as called for in the schedules.

Flanges or unions shall be provided on straight runs at not greater than 12m. Intervals.

12. PIPE EXPANSION JIONTS

Fabricate expansion loops as required

Expansion joints shall be installed where indicated and elsewhere required and approved by

engineer for adequate expansion of installed piping system .

Flexible joints shall be stainless steel corrugated below type with contour control rings , Fully

enclosed with Flanged connections . All joints shall have the traverse , The temperature and

pressure rating shown on drawing.

Guides shall be Furnished and installed on either side of each expansion joint , Additional

guides shall be installed at intervals as required .

13. PIPE TEST

Test each piping system at 150% of operating pressure indicated but not less than 150 psi test

pressure

Required test pressure is 2 hours.

The test has failed if leakage is observed or if pressure drop exceed 5% of test pressure.

END OF CHAPTER

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CHAPTER 6

VALVES

1. GENERAL:

All valves shall be designed for packing under pressure when fully open.

Shut-off valves shall be installed on both sides of all equipment , all branches from main

risers.

Balancing valves shall be installed on the outlets of air handling units & all branches from

main risers.

Check valves in horizontal position shall be l5 degree swing checks, valves in vertical

position be balanced - check valves of the low pressure drop type.

All valves shall be of 200 psi cold water non- shock pressure rating.

All gate and globe valves shall be of type that can be repacked under pressure .

Threaded valves shall be supplied with British Standard taper pipe thread.

The valves shall be labeled to comply with indications shown on the submittal circuit

diagrams.

2. GATE VALVES:

Gate valve size 2 " and smaller shall be screwed cast bronze body , bonnet and trim , solid

wedge disc , brass packing gland, Teflon impregnated packing non-rising stem , screwed

bonnet .

Gate valves size 2 1/2" and larger shall be flanged ends, cast iron body and bonnet bronze

trim, solid wedge disc ,rising stem , outside screw and yoke bronze packing gland, Teflon

impregnated packing

3. GLOBE VALVES:

Globe valves size 2 " and smaller shall be screwed, bronze body, bonnet and trim, renewable

bronze seat disc disk, , rising stem, bronze packing gland, Teflon impregnated packing

Globe valves size 2 1/2" and larger shall be flanged ends , cast iron body and bonnet bronze

trim renewable bronze seat and disc, , outside screw and yoke bronze packing gland, Teflon

impregnated packing

4. GLOBE VALVES WITH VARIABLE ORIFICE DOUBLE REGULATING

FEATURES:

Valves size 2" and smaller shall be screwed , gunmetal body and bonnet , valves 2½" and

larger shall be flanged , cast iron body and bonnet , brass stem .

5. BALL VALVES

Bronze body ,standard ports bronze ball replaceble TEF seats packing and gaskets adjustable

packing box, threaded ends, balancing stop plate, blow out proof brass stem and steel handle

with plastic cover


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5. CHECK VALVES:

Check valves size 2 and smaller shall be screwed , cast bronze body and

brass trim and spring , horizontal lift pattern , renewable disk , screwed cap .

Check valves size 2.5 and larger shall be flanged ends , cast iron body , bronze disc and seat

ring , swing type , renewable disc and seat ring, bolted cap

6. AUTOMATIC AIR VENTS:

Wherever possible, all water pipework system are to have open venting . At all high points in

the system where this is not possible ,

An automatic air vent ½" ,brass body, controlled by a ball float with renewable internal

stainless steel parts shall be fitted and connected to nearest drain .

Automatic air vents shall be fitted with a suitably sized manual gate type lock shield valve.

7. RELIEF VALVES

Relief valves shall be of the spring loaded , angle type , with screwed ends , male bottom inlet

, female side outlet ,bronze body and trim , suitable for a steam working pressure of 150 psi

they Relief valves shall be present at the factory and the pressure setting shall be clearly

stamped on the valve nameplate

8. BUTTERFLY VALVES:

Butterfly valves 5" and larger shall be flanged ,cast iron body , bronze disc , and stainless

shaft, valves 8" and above shall be supplied with reduction gear.

9. STRAINERS:

Approved "self - cleaning" strainers shall be provided in the suction line of each pump and

at the inlet connections to each feeder and make - up connections, and each automatic control

valve . The intention is to protect , by strainers , all apparatus of an automatic character ,

whose proper functioning would be interfered with by dirt on the seat, or by scoring of the

seat.

All strainers shall be suitable for pressures as stipulated for the system concerned and

shall be inspected and pressure at works .

All strainers shall be cast iron or bronze bodied of ample strength for the pressure to which

they shall be subjected and suitable flanges or tapping to connect with the piping they

serve .

Strainer basket screens shall be stainless steel and shall be of ample strength to prevent

collapsing the basket under shock loading.

Each water strainer shall be provided with an approved valve dirt blow - out connection

with suitable pipe connected to nearest floor drain .

10. FLEXIBLE CONNECTIONS:

Chillers, pumps and fan coil units, shall be connected to the chilled water pipes through

flexible connection.

END OF CHAPTER

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CHAPTER 7

EXPANSION TANKS

EXPANSION COMPRESSION TANK:

Construction: Furnish and installed expansion compression tank including supports for the

chilled water system. Tank shall be constructed of black steel ASME for 150 psi working

pressure with butyl rubber diaphragm. Reinforced tapings shall be provided for inlet and

drainage connections, gauge glasses with shut off valves and pressure gauges. Tank shall be

tested and proven tight after erection, under hydrostatic pressure of 150 psig.

Gauge glass set: brass compression stops , guard and 3/4” glass, maximum 24” long enough

to cover tank for 2” above bottom and 2” below top.

Provide manual air vent, tank drain and pressure relief valve

Automatic cooled water fill assembly: pressure reducing valve, backflow prevent, test cooks,

strainer, vacuum breaker, and bypass valve..

END OF CHAPTER

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CHAPTER 8

CHEMICAL TREATMENT

FOR CLOSED CHILLED WATER CIRCUIT:

1-Chemicals: Provide chemicals formulated from borate nitrate to provide protection against

corrosion for most commonly used pipe materials as steel, copper and brass. In addition to

polymeric discrepant to keep closed system clean, it should be suitable for use in systems

containing antifreeze additives and contain an alkaline buffer to maintain the recirculation

water and the optimum pH for maximum corrosion protection.

The following condition should be maintained in the closed system

--- PH 7--9

--Nitrate as NO2 1000-2000 PPM

2- Chemical Feed Equipment: Dosing pump shall be provided and connected to low pressure

chilled water header through 3/4" black steal pipe and valve . for feeding corrosion

inhibitor in the closed system.

General

Provide sufficient quantity of chemicals for one years use after the expiry of the period of

maintenance.

END OF CHAPTER

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CHAPTER 14

INSULATION

1. CHILLED WATER PIPING INSULATION

A- Concealed pipes

All pipe Carrying Chilled water and condense drainage shall be insulated with UL Label

preformed rigid sectional Fiber glass pipe insulation with Factory applied Flame retardant

aluminum Foil Vapor barrier laminated with Kraft paper.

The insulation shall have an average thermal conductivity not to exceed .25

BTU/HR/FT2/F

/in at mean temperature of 75 F

.

The insulation shall be fixed over clean dry pipe surface with approved adhesive with all

joints butted firmly together.

Insulation thickness shall be 1.5 inch for pipes up to 2" diameter and 2" for pipes 2 l/2"

diameter and above , insulation density shall not be less than 4 lb/ft³ .

Carry insulation at each hanger through enclosed 300 mm covering shield of 1.5 mm thick

galvanized steel sheet .

B- Exposed pipes :

* Insulation of pipe work installed in machine rooms and exposed to outside weather shall

be protected with aluminum casing 0.7 mm thick .

* Insulation of pipe work installed under ground shall be protected with 3 layers of roofing

felt finished with asphalt coating.

2. EQUIPMENT INSULATION :

Cold equipment : Fill voids between insulation and equipment with blanket insulation and

cover with removable aluminum sheet metal jacket lined with 1" inch thick rigid board

insulation .

3. ACOUSTIC DUCT LINING :

Acoustical lining l" thick shall be fixed to the internal duct surface of each air handling unit

and FCU supply and return duct fans for a length of at least 4 meters from the unit , or as

indicated on the drawings.

Such acoustic lining shall be mat - facing of black neoprene duct liner of 2.5 lb/ft³ density.

Dimensions of lined ducts shown on drawings are the inside dimensions of the duct after the

lining has been installed . Stapling method of attachment will not be permitted.

Mat-faced duct liner shall be adhered by a fire retardant approved. adhesive.

Mechanical fasteners which do not pierce the sheet metal shall be on l6 inch centers on top

section when width exceeds l2 inches , and on sides when height exceeds 24 inches.


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All abutting edges of acoustic lining shall be calked,and all exposed edges of acoustic lining

shall be installed with sheet metal housings.

END OF CHAPTER

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CHAPETER 10

FOUNDATION AND VIBRATION ISOLATION 1. GENERAL

All equipment, piping and ductwork shall be mounted on or suspended from approved

foundation and supports all as specified as shown and as required, all concrete foundations

including thickened structural slap, housekeeping pads and concrete for inertial pads shall be

provided. .all pipes installed up to 15m from equipment shall be supported on vibration

isolator.

Provided shop drawings and templates for all concrete foundations provide necessary integral

steel framings, concrete reinforcing rods welded to frame, required anchors bolts, spring

mountings and neoprene pads.

The foundations and vibration isolation mountings for the various equipment piping and

ductwork shall be in accordance with the requirements as detailed on the drawings and as

specified.

Where spring vibration isolators are called for they shall be horizontally stable bare springs

unless otherwise indicated. Static deflections shall be minimum 1.5” unless otherwise

indicated and selections shall include 50% additional reserve deflection.

Where a ribbed rubber assembly is called for shall be factory fabricated from two thickness

unless otherwise indicated, of 0.25 inch thick ribbed neoprene pads and shall be square in

shape. Pads shall be arranged so that ribs pun in opposite directions. Between each pad shall

be 1/16 inch thick galvanized steel shim plate integrally and permanently bounded to the

neoprene pad and base plate.

2. MOUNTING OF AIR HANDLING UNITS

Mount unit directly on an integral rigid steel base which shall in turn be supported by a

suitable number of spring vibration isolators. Each spring isolator shall be mounted on a

ribbed rubber assembly. Minimum static deflection of 0.75 inch and then mounted on 6 inch

thick. concrete base .

3. MOUNTING OF SUSPNDED FANS

Units shall be hung on resilient hangers. These hangers shall be combination rubber-in-share

and spring hangers. Each unit not having sufficient frame rigidity shall be provided with an

integral steel base for support of the suspended fan unit. Minimum static deflection 1.0 inch.

4. MOUNTING OF PUMPS

Mount all base mounted pumps directly on a concrete base which in turn shall be mounted on

a 2 inch thick heavy density cork., when pumps are located in basement where no floors or

services blew it can be mounted directly on concrete base of minimum thick 10inch.

5. MOUNTING OF CHILLERS

Chillers structural steel frame shall be mounted on spring vibration isolators which in turn

shall be mounted on neoprene ribbed rubber assemblies. The chillers shall be mounted on 8

inch thick concrete plinth base

END OF CHAPTER

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CHAPTER 11

METERS AND GAGES

1. TEMERATURE GAGES

A. Glass thermometers

1. General: provide glass thermometers of material and ranges as indicated.

2. Case: die cast aluminum finished in baked epoxy enamel, glass front, spring secured (9)

long.

3. Adjustable Joint: Die cast aluminum, finished to match case, 180 adjustment in vertical

plane, 360 adjustment in horizontal plane, with locking device.

4. Tube and Capillary: Mercury filled, magnifying lens 1% scale range accuracy,

5. Scale: stain faced, non-reflective aluminum, permanently etched markings.

6. Stem: copper-plated steel or brass, for separable socket, length to suit installation.

7. Range: Chilled water: 30-100F (0 -40)

B. Direct Mount Dial Thermometers

1. General: provide direct mount dial thermometer of materials , and ranges indicated.

2. Type: vapor tension, universal angle.

3. Case: Drawn steel or brass, glass lens (4 1/2) diameter.

4. Adjustable Joint: Die cast aluminum, 180 adjustment in vertical plane 360 adjustment in

horizontal plane with locking device.

5. Thermal Bulb: copper with phosphor bronze bourdon pressure tube, on scale division

accuracy.

6. Movement: Brass precision geared.

7. Scale : progressive , stain faced non reflective aluminum, permanently etched markings.

8. Stem : copper plated steel, or brass for separable socket , length to suit installation .

9. Range: :Chilled water : 30 -100F (0 -40c).

C. Thermometer wells:

Provide thermometer wells constructed to suit piping system design pressure. , provide

(2) extension for insulated piping

D. Locations:

Install in the following locations and elsewhere as indicated

1. At inlet and outlet of each coil. of AHU

2. At inlet and outlet of each chiller.


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2. PRESSURE GAGES AND FITTINGS

A- Pressure Gages

1. General: provide pressure gages of materials, and ranges as indicated,

2. Material :Drawn stainless steel case with push in lexan window, white .

Coated metal dial , lithographed with black graduation lines and numerals

3. Pointer : Slotted micro-adjustable

4. Bourdon tube & socket : bronze bourdon &brass socket

5.Accuracy : 1%

6.Movement: All brass construction, precision gear and pinion

7.Case size = 4:1/2 dia Stainless steel case gouge .

8. Range: conform to the following : water 0- 689 kpa ( 0-100 psi)

B. Pressure Gage Cocks

1. General: provide pressure gage cocks between pressure gage and gage tees on

piping systems. Construct gage cock of brass with 6mm (1/4) female

3. Snubber: 1/4 brass bushing with corrosion resistant porous metal disc, through

which pressure fluid is filtered . Select disc material for fluid served and pressure

rating .

C. Locations:

-Install at suction and discharge of each chiller.

- Install at suction and discharge of each pump .,read differential pressure between suction

and discharge with the same apparatus.

-- Install at suction and discharge of each AHU coil

3. FLOW MEASURING GAGES

A- Calibrated Balance Valves:

Provide as indicated, calibrated balance valve equipped with readout in valves to facilitate

connecting of differential pressure meter to balance valve and designed to minimize system

fluid loss during monitoring process.

Construct balancing valve with internal seals to prevent leakage around rotating element,

provide balance valves with preformed polyurethane insulation suitable for use on cooling

system, and to protect balance valves during shipment.

Maintain minimum length of straight unrestricted piping equivalent to 3 pipe diameters

upstream of the valve.

END OF CHAPTER

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CHAPTER 12

AUTOMATIC CONTROL SYSTEM

1. GENERAL:

The contractor shall furnish and install all required controls and appurtenances to provide

complete and satisfactory automatic control of the systems (DDC).

All control equipment shall operate with 24V± 8%, 50HZ and required accuracy ± 5% of the

setting.

Operation shall be guaranteed up to an ambient temperature of 50 ْC.

All HVAC control devices shall be electrical protected by means of a specific supply line

against voltage drop and city power failure ± 10 V.

The contractor shall furnish and install all necessary apparatuses such as controllers ,sensors,

switches, relays, transformers,...etc. and all control wiring and conduits to effect the

automatic operation of the control systems intended by the design. He shall make all

necessary connections to the control instruments and equipment as required for the control

systems.

The contractor shall submit for approval by the engineer complete control wiring diagram &

sequence of operation for the control systems intended, showing all control instruments,

auxiliaries and accessories.

All control instruments and appurtenances shall be the product of one reputable, specialized

and approved manufacturer.

All control instruments shall be of the latest design and shall be as recommended by the

manufacturer for the control systems intended.

All controls shall be specially supplied for the available electric current characteristics.

All controls shall be installed and connected in accordance with manufacturer's instructions.

All controls and instruments shall be installed in such a manner and at such locations as to

sense accurate representative value of the function that they control to be accessible for ease

of adjustment and calibration.

Wall mounted thermostats shall be installed at 1.5 m above floor level on an inside

wall and where the temperature at the thermostat is not affected except by room

temperature.

Control valves shall always be installed in the horizontal position with motor in the vertical

position.

Immersion type thermostats and thermometers shall have their bulbs inserted in special

brass separable socket wells that shall be installed in the vertical position or at an angle so as

to retain oil. Socket wells shall be installed through female threaded steel fittings welded to

the pipe and shall be of insertion depth to suit the pipe in which they are installed.

Surface mounted control devices shall be mounted on brackets of an approved design to clear

the final finished surface of insulation.

All control wiring and conduits shall be concealed in all areas except in mechanical

equipment room and in unfinished spaces.


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Unless otherwise specified temperatures shall be controlled to within plus or minus 1 F

and humidifies to within plus or minus 5% of the specified design conditions .

The contractor shall install mimic panel in the pump room indicating all control signals for all

chillers, pumps, air handling units, exhaust and supply fans ....etc.

2. DDC STAND ALONE CONTROLLER:

2.1 Introduction:

For automatic and cost-effective operation of all building services installations, a freely

programmable, digital management system is to be offered. The system must be capable of

performing all control and interlock functions, and energy optimization as well.

The measuring, control and interlock units are autonomous DDC system required to carry out

all functions independently of higher order management system.

The supplier has to prove that both the hardware and the software of the measuring ,

control and interlock system offered constitute and self - contained system development,

supplied by a manufacturer who assures long - term system maintenance.

2.2 Operational Reliability:

For high operational reliability and system accessibility the system offered needs strictly

distributed intelligence. It is therefore absolutely necessary that all building services

installations are equipped individually with a stand - alone DDC substation.

All data must be saved, even in the event of a power failure Power failures and spikes on the

power lines must not lead to a loss of data, The buffer has to be designed such that in the

event of power failures the data are saved.

A fault in a DDC substation must not impair operation of other interconnected substations.

Any fault detected in the system or the plant must be reported to higher order operator

terminals. Fast locating of faults must be assured.

2.3 Communication:

For future integration of autonomous DDC system into a higher order management system,

the individual components need communication capabilities without modifying the hardware

or the software.

In order to exchange common data (e.g. outside temperature, common

Operation, .etc. ) the individual devices are to be interconnected via an

industrial bus system.

For decentralized operation, the autonomous control and interlock modules have to be capable

of communicating up to a maximum bus length of 1200m, without requiring any additional

devices.


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2.4 Operation:

Depending on the requirements specified in the tender document each individual plant is

operated via an operator terminal for access to each individual device and, centrally, to all

connected building services installations via an RS-bus.

Step - down control circuit transformers or the two winding isolating type shall be provided.-

provide separate transformers for sensors and actuators

High rupturing capacity fuses or circuit breakers shall be used for protection of the control

circuit.

Auxiliary supply for controls other than from the main power circuit shall be effectively

isolated by auxiliary contacts on a main isolator.

All motor starters and controls shall be provided with an engraved nameplate identifying the

system or defining its function.

A detailed wiring diagram shall be securely fixed inside each enclosure cover to indicate

clearly all circuits.

All control and power wires shall be clearly numbered and marked for identification by

distinctive color of insulation.

3. FIELD EQUIPMENT:

3.1 Sensors (Room and Duct)

Temperature sensors shall be two wires screened connections to the associated controllers.

Humidity sensors shall sense changes in relative humidity by mechanical means, conversion

to an electrical output shall be by a friction free inductive coupling. Connections shall be by

screened wiring to the associated controllers.

temperature and humidity sensors shall require four wire connection to the associated

controllers and shall not be susceptible to interference. Output of temperature and humidity

sensors shall be compatible so that the controllers are interchangeable.

Duct mounted sensor shall have t\rigid stems or capillaries on sensing bulbs

The operation differential shall not exceed 3 C for full load conditions

Sensors shall consist of a base plate to which the electrical connections are made.

The sensors housing shall plug into the base so that it can be removed easily without

disturbing any wiring connections.

Combined temperature and humidity sensors shall plug into a common base plate.

3.2 Control Valves:

The valve shall be fully modulating 3 way mixing or straight through type, as required ,

complete with motor and linkage of the spring return type and has the ability to be

opened and closed manually.

Valve size 2 " or less supplied and screwed with union fittings .

Valves of size above 2 " shall be flanged.

Two way valves shall be used for liquids which have equal percentage characteristics, and

three way valves shall be used for liquids which have linear characteristics .Size valve

operators to close valves against pump shut off head . Size for maximum 3 psi drop.


29 | P a g e

3.3 Air Pressure Switch:

The pressure switch shall comprise two chambers connected to a diaphragm, the chambers of

the device shall be arranged so that device can be used for a static pressure or differential

pressure switch as specified

Connection to the device shall be by means of a plastic tube to the points to be measured on

the duct via a plastic serrated coupling .

The pressure switch shall be supplied complete with duct sampling connections and plastic

connecting pipe

Shall have differentials over 10% to 30%

Set point shall fall within 40% to 70% of the scale range

3.4 Pressure switch for pipework

Shall be bellow operated and to be suitable for the working temperatures and pressures. the

pressure switch shall be capable of withstanding a hydraulic test pressure 1.5 ties the working

pressure

Shall be suitable for pipe or wall mounting

Shall have differentials over 10% to 30%

Set point shall fall within 40% to 70% of the scale range

3.5 Water flow switch

Shall be selected for the correct water velocity and pipe

3.6 Damper Actuators:

Damper actuators shall be of the direct coupled type to either modulating or two or three

position control. Actuators shall stroke by a rotating motion of a reversible overload - proof

synchronous motor. Control voltages shall be either 24 VAC or 0 - 10 VDC as required by the

application. All actuators shall have a hand operating facility and position indication marked 0

– 10% indication 0-100 %.

On modulating types the direction of operation and stroke limitation shall be adjustable

without mechanical changes in the linkage.

Modulating and two position types shall be available with spring return, the spring return time

shall not be more than 3 seconds.

4. CONTROL WIRING:

Wires and cables for the control circuits shall be rated for 220 volts service.

Insulation shall be moisture resistant and flame retardant PVC compound.

Conductors shall be tinned annealed of a minimum 1.5 sq. mm area. Multi - core cables for

control and signaling shall be PVC insulated copper conductors PVC sheathed.

Where required special heat resistant insulation or corrosion resistant sheath shall be

provided.


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5. CONTROL PANEL SECTION FOR DDC - COMPONENTS:

Should be in robust steel construction, with mounting plate doors and hinges inside

Size and color of the control panel (as specified by the supplier) complies with the design of

the power distribution system.

The space required is to be assessed from the technical data of above devices.

For the interface between the control section and the power section, a terminal strip is

required The installation regulations of the DDC - system manufacture must be observed

and included also the terminals connected in series ,the necessary small accessories and

the fastening equipment mounted , wired and factory - proven

All control panels and operating panels which enable the operator to operate, stop, and read

the temperature degrees and the exhaust - supply fans are located in the pumps room.

It is essential to make sure that all the wires and the cables between the control panels in the

pumps room and the air handling units and the fans are low voltage wires which means, that

there are no power transferred between the control panels and the air handling units and the

only signals transferred between them is the control signals.

6. CONTROL SEQUENCE FOR CHILLERS AND PUMPS:

At full load, chilled water pump, are turned on and then chillers are turned on

When one chilled water pump fails to start from each circuit , the standby shall operate

automatically, duty and standby pumps shall be alternated automatically at each cycle.

Chillers shall not start unless chilled water pumps, are already on, this in turn activates the

flow switch of the chiller, then the chiller can be started.

Normal shut down: the chillers are first turned off , and water pumps are stopped after a

dedicated time delay together with the chiller isolating valves.

The D.D controller should be able to make a sequence control, time scheduling and time

delay for the chillers according to load requirement.

7. CONTROL SEQUENCE FOR TOTALLY OUTSIDE AIR AHU's

Supply temperature sensor will sense the temperature and controller will signal 3 - way

modulating valve to position according to load requirement. (Positioning time should not

exceed 10 seconds for optimum energy saving ).

Differential pressure switches to monitor filter, and fan belt status. Smoke detector to detect

smoke and shut the whole system in case of smoke detection.

ON / OFF damper actuator on the outside to shut the outside damper whenever AHU is shut

down .

8. CONTROL SEQUENCE FOR RETURN AIR A.H.U.'S

Room temperature sensor will sense the temperature and controller will signal 3 - way

modulating valve to position according to load requirement and control

required steps. Differential pressure switches to monitor filter and fan belt status

whole system in case of smoke detection.


31 | P a g e

Temperature monitoring of outside and common return air ducts. Humidity monitoring of

outside and common return air ducts. Differential pressure switches to monitor filter, supply

and return fan belt failure.

Duct smoke detector is mounted on return, in case of smoke detection , the detector will

stop the supply fan and shut off the damper in the mixing box, DDC will report smoke alarm

to EMS if available

9. FAN COIL UNITS CONTROL:

Fan coil units will be thermostatic controlled with a two/three way valve for cooling and one

stage electric heater for heating.

The room operating unit thermostat will have a 3-speed switch with a set point potentiometer

and a heat / cool / fan positioning switch with a temperature range of (5-30) C.

Two ways will be brass valve body and it will be closed in de-energized position. Seat and

disc material will be nickel chromium steel, Admissible water temperature 2 - 120 C.

10.Samples

Sample thermostat shall be provided by the contractor for approval by engineer

11.Accuracy

Control and measuring devices shall have the following limits of accuracy

Temperature 0.5 C

Pressure 5% of measured value

Humidity 5% rh

END OF CHAPTER

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32 | P a g e

CHAPTER 13

WATER BALANCING AND TESTING

1. GENERAL REQUIREMENTS:

The contractor shall perform all testing, and balancing and shall adjust systems as described

hereunder including but not necessarily limited to the following:

Pressure testing of all refrigerant piping systems to ensure their tightness under the prescribed

test pressure.

Balancing and adjusting air distribution systems to deliver the required air quantities

indicated on the drawings.

Testing of equipment performance to demonstrate conformity with design requirements and

proper functioning.

Testing of all controls to verify that they are operating satisfactorily as intended.

Testing of systems as a whole to demonstrate their adequacy to meet design requirement

All tests shall be conducted in the presence of the engineer and as directed by him.

All measured tesr date shall be recorded and submitted to the engineer in the report form for

his review and approval.

The contractor shall provide all labor, equipment, material, instruments, power and

connections required to execute testing, balancing and adjusting operations as directed.

All expenses incurred by testing operations shall be borne by the contractor including the cost

of repair or replacement of defective work, cost of restoring, repairing or replacing damaged

work resulting from the tests and the cost of replacing defective or inadequate equipment

and material all as directed by the engineer.

All expenses incurred by testing operations shall be borne by the contractor including the

cost of repair or replacement of defective work , cost of restoring, repairing or replacing

damaged work resulting from the tests and the cost of replacing defective or inadequate

equipment and material all as directed by the engineer.

2. WATER PRESSURE TEST:

All piping systems shall be hydrostatically tested for ensuring complete tightness under

the specified test pressure.

Systems can be tested as a whole or in part to facilitate the progress of the work.

No part of a piping system shall be painted, covered or enclosed until it has been tested,

inspected and approved.

No part of a piping system shall be tested to a pressure of less than 150 psig (10 kg / sq. cm)

measured at the highest point of the system.

No equipment device or accessory shall be subjected to a pressure exceeding its

prescribed test pressure as obtained from its nameplate data or from manufacturer's

published data. Pressure tests shall be applied before connecting piping to equipment. Relief

valves, instruments, automatic air vents, diaphragm valves and all devices that might be

damaged by the test pressure shall be removed, disconnected or blanked of .


33 | P a g e

No pressure shall be applied against the closed gate of gate valves. All valves shall be

in the open position but not completely back seated during testing. End valves shall

be capped.

In testing flanged piping, temporary blank flanges shall be installed and firmly anchored to

accommodate all developed end thrust.

All piping that can be damaged by end thrust developing from hydrostatic testing shall be

properly anchored during testing especially at changes of direction.

A piping system to be tested shall be closed by plugging and planking off all openings in

the system and filling slowly with water making sure to vent all entrapped air. Plugs

shall be released temporarily to ensure that has reached all parts of the system.

Pressure shall be applied to the system by means of a hand pump drawing from water

container. The pump discharge shall be connected to the system through a globe valve ,

check valve and recently calibrated pressure gauge of suitable range to have the test pressure

read in the middle of the range.

After the test pressure is reached, the pump shall be blocked off by closing the globe valve

and the variations of pressure in the system shall be monitored on the pressure gauge.

The test pressure shall be maintained on the system for 24 hours during which time

the system shall have no noticeable drop in pressure.

While the system is under pressure, careful inspection shall be made of all pipes and joints

and if any leaks in joints or evidence of defective pipe or fitting is disclosed the defective

work shall be corrected by replacing defective parts. No makeshift repairs or

application of any repair compound will be permitted.

After the correction is made the pressure test shall be repeated until completely tight system

is ensured.

The test pressure shall be released slowly so as not to produce shocks and sudden contractions

that might cause damage to the piping.

3. Testing & Balancing Procedure:

(A). Air Systems:

-Balancing of air systems:

-Test and adjust fan RPM to design requirements.

-Test and record motor full load amperes.

-Adjust CFM at main supply ducts and compare with design CFM

-Adjust CFM at main return ducts and compare with design CFM

-Adjust CFM at out side air louver and compare with design CFM

-Test and record entering air temperatures. (DB heating and cooling).

-Test and record entering air temperatures (WB cooling).

-Test and record leaving air temperatures. (DB heating and cooling).

-Test and record leaving air temperatures. (WB cooling).

-Adjust all zones to proper design CFM and compare with design.

-Test and adjust each diffuser, grille and register to within 5% of design requirements,

-Each grille, diffuser shall be identified as to location and area.

-All diffusers, grilles, and registers shall be adjusted to minimize drafts in all areas.


34 | P a g e

B. WATER SYSTEMS:

-Open all valves to full open position.

-Remove all strainers and clean it.

-Examine water in system and determine if water has been treated and

cleaned.

-Check pump rotation.

-Check all air vents at high points of water systems and determine that all -are installed

and operating freely. Bleed all air from manual vents.

-Set all temperature controls so all coils are calling for full cooling.

-Record actual running amperage of pump motor.

-Record water metering device readings.

-Record inlet & water temperature at each coil.

-Upon completion of flow readings and adjustments at coils, mark all settings and record

all data .

END OF CHAPTER

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35 | P a g e

CHAPTER 14

ELECTRICAL WORK

1. GENERAL:

The contractor shall execute all the electrical work connected with and necessary for the

operation and control of the HVAC systems.

The electrical work provided under this division shall include but not necessarily be limited to

the following:

*All motors for electrically operated equipment.

*All power and control panels including starters, motor protection, control and *isolation

equipment, devices, accessories, and interconnecting and interlock wiring.

*All power cables , wiring and conduits to equipment from the power supply points .

*All wiring and conduit for connecting control instruments to equipment’s.

*All automatic control instruments , accessories , sensing devices , sequencing relays etc. as

specified and as required for the control and operation of equipment .

*Earthing of all metal frames of boards , panels , enclosures , supports , tray and motors.

*Excluded from the work under this division of the specification and provided under

electrical installations Division are the following:

- Main feeders to switch boards.

- Power supply to convenient point close to HVAC equipment

- Distribution boards

2. STANDARD:

All electrical equipment and accessories supplied by the contractor shall be manufactured in

compliance with:

-The latest issue of IEC standards.

-B.S standard.

-NEMA standard.

3 . MOTORS:

Electric motors shall be supplied by the manufacturer of the driven equipment and shall be as

specified for the equipment concerned . Any electric motor not in accordance with the

specification shall be rejected All electric motors shall be specifically supplied for the

available supplied voltage and frequency as verified from the electrical drawings Motor speed

shall be as specified for the equipment concerned .

Unless otherwise specified electric motors below 0.5 horsepower shall be single phase and

above 0.5 horsepower shall be 3 phase squirrel cage of the totally enclosed fan- cooled type.

All electric motors shall have adequate power to operate the driven equipment without motor

overload under all conditions of operation and load and throughout the capacity range of the

equipment.

Any overloaded motor as evidenced by its drawing current exceeding its nameplate current

rating and/or overheating under the specified operating conditions shall be rejected.

All electric motors shall have starting and torque characteristics as required by the driven

equipment and shall be capable of delivering the full rated output when operating at voltages

deviating by 5% from the rated voltage at the rated frequency .Motors shall be rated for

continuous operation .


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Electric motors shall have class B insulation with 80 C continuous temperature rise above an

average ambient temperature of 40 C unless otherwise specified

Motors operating in ambient temperatures exceeding 40 C shall be tropicalized and derated

for satisfactory operation. Motors installed outdoors shall have class F insulation.

All motors shall be provided with conduit terminal box of approved model for the type of

motor enclosure. The motor windings shall be connected to terminals in the terminal box at the

factory. One additional earthing terminal shall be connected to the motor frame.

Motors directly connected to driven equipment shall be furnished with an adjustable base

unless otherwise specified . Motors connected to equipment through a V - belt drive shall be

furnished with an adjustable sliding base . Fractional horsepower motors shall be furnished

with slotted mounting holes in the base.

Where motors are not readily visible from the control panel positions, a lock stop push button

shall be provided adjacent to the motor .

4. CABLES:

LV power cables shall be 4 core steel wire or double steel tape armored cables with copper

conductors to BS 6346 or IEC equivalent. Alternatively multi-core PVC insulated and

PVC.sheathed cables shall be used where permitted on the drawings . This shall be 0.6 / 1KV

insulation .

Core shall be used for single phase circuits and 5 core for three phase circuits . Single phase

cable colors shall be in accordance with the clauses on conductor color codes , i.e. the earth

conductor shall be green or yellow /green .

All cable ends shall be terminated using bras cable glands complete with brass lock nuts ,

earth tags and shrouds .

Cables run above ground shall be adequately supported . Single runs of cable shall be

supported by purpose made nylon reinforced or die cast cable cleats with a secure fixing to the

building structure. additional steelworks supports shall be provided where necessary . Spacing

shall be in accordance with the IEE regulations. Multiple runs of cable shall be supported on

cable trays as specified .

When cables pass through walls and floor slabs , each cable sleeve or opening shall be filled

with foaming material to prevent fire propagation , after installation of the cable .

5. CONTROL WIRING:

Wires and cables for the control circuits shall be rated for 220 volts service Insulation shall be

moisture resistant and flame retardant PVC compound .

Conductors shall be tinned annealed of a minimum 1.5 sq. mm area.

Multi-core cables for control signaling shall be PVC insulated copper conductors , PVC

sheathed in accordance with B.S. 6346.

6. CONDUITS:

Unless otherwise specified gauge steel conduits shall be used throughout for all power and

control wiring .

However , rigid conduits shall not terminate in or be fasted to a motor frame or base .

Flexible conduits shall be used to avoid transmission of noise and vibrations .


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Flexible conduits shall be manufactured from welded and drawn heavy gauge steel to BS 31 ,

class “b” or approved equal .

Conduits shall be internally and externally galvanized and threaded at both ends .

The minimum size of conduit shall be 20 mm. internal diameter unless otherwise specified .

Conduit fittings such as couplings expansion couplings , clips saddles , elbows , glands ,

adopters , reducers and the like shall be specifically designed for the type and size of conduit

used .

7. STARTERS:

The starters shall be electromagnetic air break type suitable for 3 phase , 50 HZ , 380 V , to

BS 4941 or IEC 292 rated to suit equipment served .

All starters shall be equipped with thermal overcorrect relays for motor protection.

All starters shall be equipped with one normally open and normally closed auxiliary contact in

addition to those required to carry on the functions called for provide for remote start/stop ,

automatically starting ( starter initiated from another starter or device ) , manual start ( at

MCC or elsewhere ) , lockout , monitoring ( remote pilot ), interlocking , etc. , as required .

Star - Delta starters ( reduced voltage starter ) with change over setting as desired , starting

from 3 to 10 seconds , to be confirmed with manufacturer .

Where specified all automatic starters controlled by another starter shall have delay starting to

avoid inrush current , if the two motors start together.

All automatic starters shall have on their switchboards a selector switch for automatic / manual

( via push - button ) and off.

Unless otherwise shown on the drawings or required by the driven equipment all motor

starters shall be of the following types:

- Type A single phase motors below 0.5 HP the starter shall be of the manual two – pole

toggle type for non - reversing across the line starting and fitted with one overload element . It

shall be of the surface of flush mounted type.

- Type B for 3 phase motors up to and including 10 HP the starter shall be of the direct - on

line non reversing magnetic type with a manual reset, 3 pole overload relay and low voltage

protection .

- Type C for 3 phase motors above 10HP and up to and including 50 HP the starter shall be of

the automatic star-delta magnetic non- reversing type with a 3 pole overload relay and one

adjustable low voltage relay.

- Type D for 3 phase above 50 HP the starter shall be of the multiple- step auto-transformer

non-reversing magnetic type with a 3 pole overload relay , one adjustable low voltage relay ,

one earth leakage relay and unbalanced current protection .

Individually mounted starters shall be totally enclosed in a sheet steel enclosure with baked

enamel finish and of a design to suit the location and application . It shall not be possible to

open the enclosure door unless the isolator is in the open position .


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8. PUSH BUTTONS AND RELAYS:

Push buttons shall be a one unit momentary contact START / STOP with normally - open or

normally - closed contacts as required by the wiring diagram and with lookout attachments.

Push button head shall be color coded and the STOP push button shall be protected .

Relays shall be multi-pole with normally - open or normally - closed contacts , electrically

operated at 220 v maximum , 50 cycles and magnetically held .

Contacts shall be of the double - break , served type and interchangeable from normally -

open to normally - closed without additional parts .

9. CIRCUIT BREAKERS:

The circuit breakers shall be three phase , moulded case type , of air break type ,quick make

and quick break having Free toggle mechanism ensuring full contact pressure until time of

opening whether actuated automatically or manually operating voltage 380 V , 50 Hz , rated

current and suitable to motor name plate and complete with :-

a-Overload protection by delayed thermal over current releases adjusted between 0.8 and 1.25

times the rated current .

b-Short circuit protection by electro-magnetic releases instantaneously operated and

adjustable .

All outgoing circuit breakers shall have rupturing short circuit capacity 40 KA complying

with the design conditions mentioned herein .

All circuit breakers feeding motors , shall withstand the starting conditions of these motors .

Selection of the suitable circuit breaker and the backup fuses for all types of motors shall be

the full responsibility of the contractor

10. CONTACTORS:

All contactors shall be to BS 5424/1 , three phase , rated voltage 380V, with operating coil

220 VAC complete with thermal overload protection adjusted between 0.8 and 1.25 times the

rate current shown on the drawings . They shall have sufficient auxiliary contacts for

interlocking and automatic transfer .

11. CURRENT TRANSFORMERS :

Provide current transformers to be of the bar primary type , air cooled and suitably insulated

. They shall be of class 1 accuracy for measurement and of class 10P10 accuracy for

protection in accordance with IEC 185 , the secondary windings shall be rated at 5A and the

rated output shall be suitable for the burden.

13. MEASURING INSTRUMENTS :

Ammeters shall be AC , moving iron , flush mounting , with 20% overload scale , accuracy ,

to BS 89 .

Voltmeter shall be AC , moving iron , flush mounting to BS 90 scaled 0-500 volt , and

provided with 6 position selector switches allowing reading of line to line and line to neutral.

provide maximum demand indicators of the thermal type with a 20-minute time delay .


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14. CONTROL CIRCUITS:

The control circuits shall be arranged in a manner to satisfy the operating requirements

indicated on the drawings and specified for the various equipment driven by electricity and

any other requirements pertaining to the proper functioning and operation of the equipment.

The contractor shall thoroughly acquaint himself with all the requirements of the various

systems submit to the engineer for approval detailed control wiring diagrams and a list of

control equipment with descriptive literature.

KWH meters shall be provided ,counter shall be cyclometer type with no pointers

preferably with at least 6 figures .

The meters shall be substantially made and shall comply with the relevant BS

Current transformer operated meter shall have slide on ring or bus bar type transformer for

each phase and the counter shall read the primary power directly.

15. EARTHING :

Equipment shall be earthed by connecting all non-current carrying metal parts of the wiring

system to an source.

Non-current carrying metal part shall include such items as metal conduits, cable trays, outlet

boxes, cabinets etc. as well as enclosures, doors, grilles and barriers protecting or shielding

electrical equipment from direct access by unauthorized personnel.

Motors shall be earthed by connecting a green insulated conductor from an earthling bushing

in the starter to the motor frame.

16. MOTOR CONTROL PANEL:

The motor control center shall be of the totally enclosed free-standing section type with the

sections joined together to form one assembly.

Each section shall be so designed as to allow other sections to be easily added or removed as

required .The motor control center shall be constructed of steel sheet 2mm thick adequately

reinforced and braced for maximum rigidity. It shall be painted by spray gun with one prime

coat and two finish coats both inside and outside.

The motor control shall contain but not necessarily be limited to the following:

- Main incoming circuit breaker or isolating switch as shown on the drawings for

terminating the incoming supply cables and isolating the bus-bar system .

-Main bus-bar of copper rated as the main incoming circuit breaker.

Branch copper bus-bars of adequate capacity to distribute power to each circuit breaker

and starter served .

-Neutral copper bus-bar rated at half the capacity of the main bus--bar and distributed

throughout the whole motor control center .

-Earth copper bus-bar of minimum 25mm X 6mm dimensions extending along the full

length of the motor control center .

One voltmeter, range 0-415 volts .

One voltmeter,

-Ammeters on the main supply with the necessary current transformers .

-KW meter

All necessary starters , circuit breakers ,push buttons, indicating lights, switches, relays ,

contactors , and accessories as shown on the drawings and all necessary interlock wiring .


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-All bus-bars shall be adequately isolated and shall be braced to sustain the maximum

possible short circuit current .

-All compartment doors shall be so interlock that the isolator or breaker shall be in the OFF

position before the door can be opened .

Enough space positions shall be provided . A space position shall be a fully equipped cell

ready to receive a control unit in the future . Space positions shall have blank cover plates .

-All starters , switches and other components and electrical devices shall be clearly labeled as

to number and function in English with incised letters on black bakelite with white laminated

core . The labels shall be fixed in a permanent manner under each component .

-

Clear schematic and wiring diagrams shall be firmly fixed within the motor control center

showing each component and cross-referenced with the component labels .

Prior to fabrication or purchase of the motor control center the contractor shall submit for

approval the schematic diagram of the whole installation , the suggested layout of the motor

control center , interior wiring details and complete technical literature on all components

used .

END OF CHAPTER

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INDEX

CHAPTER TITLE

1 GENERAL PROVISION

2 AIR COOLED CHILLERS

3 CENTRIFUGAL WATER PUMPS

4 FAN COIL UNITS

5 PIPEWORK AND FITTING

6 VALVES

7 EXPANSION TANK

8 CHEMICAL TREATMENT

9 INSULATION

10 FOUNDATION AND VIBRATION

ISOLATION

11 METERS AND GAGES

12 AUTOMATIC CONTROL SYSTEM

13 WATER BALANCING AND TESTING

14 ELECTRICAL WORK

Mechanical Specification

Documents

Transcript of Mechanical Specification