API RP 1102 - 1993

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PIPELINE ENGINEERING

ASSIGNMENT IINadia Handayani 4210 100 053

Jurusan Teknik Sistem Perkapalan

FTK ITS

Surabaya - 2013

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Nadia Handayani 4210100053

Pipeline Engineering Assignment 3

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API RP.1102 - 1993

STEEL PIPELINES CROSSINGRAILROADS AND HIGHWAYS

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No. Key Issue Description Value/Formula Reference

1. SCOPEGeneral This code covers Design

Installasion Inspection Testing

Para. 1.1

Application This practice applies to welded steel pipelines The construction of pipelines crossing under

railroads and highways

Para. 1.2

2. SYSMBOLS, EQUATIONS, DESCRIPTIONSEquations All stresses below have units of psi or kPa

a. Earth Load Para. 2.2Eq. 1

b. Live Load

Para. 2.2Eq. 2 - 6

c. Internal Load ( ) a. Natural Gas

[() ] b. Liquids

[() ]

Para. 2.2

Eq. 7 8b

d. Limits of Calculated Stresses a. CircumferentialS1= SHe+ SH+ SHi

b. LongitudinalS2= SLEST (T2T1) + s(SHe+ SHi)

c. Radial S3=p =MAOP orMOP

Para. 2.2

Eq. 9 20

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( ) ( ) ( ) RFSLr NL SFG F SLh SFG F SH SFL F SHr NH SFL F SHh SFL F

3. PROVISIONS FOR SAFETYApplicable regulation Federal, state, municipal or other regulating bodies Shall be observed during the installation of a crossing Para. 3.1

The hazards involved Guards (watch persons) should do Should be posted and placed :Warning signs, Lights, and flares

Should be provided and maintained :Temporary walkways, fences, and barricades

Para. 3.2

Drainage ditches Should be maintained to avoid flooding or erosion Para. 3.64. UNCASED CROSSINGS

Type of Crossing Focuses specifically on the design of uncased carrier

pipelines

Para. 4.1

General The carrier pipe shall be welded In accordance with :

API Standard 1104 ASME B31.4 or B31.8

Para. 4.2

Location and Alignment The angle of intersection between a pipeline crossing andthe railroad or highway

Near to 90 degrees Not less than 30 degrees Para. 4.3.1

Vertical and horizontal clearances Must be sufficient to permit maintenance Para. 4.3.3

Cover Railroad Crossings Location :

a. Under track structure properb. Under all other surfaces within the right-of-way

or from the bottom of ditchesc. For pipelines transporting HVL, from the

bottom of ditches

Min. Cover :

a. 6 ft (1.8 m)b. 3 ft (0.9 m)c. 4 ft (1.2 m)

Para. 4.4.2

Highway Crossings Location :a. Under highway surface properb. Under all other surfaces within the right-of-way

Min. Cover :a. 4 ft (1.2 m)b. 3 ft (0.9 m)

Para.4.4.3

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c. For pipelines transporting HVL, from thebottom of ditches

c. 4 ft (1.2 m)Design Design procedure :

(shown schematically in Figure 2)

a. Determine the pipe, soil, construction, and operationalcharacteristics

b. Calculate SHi(Barlow)c. Calculate SHed. Calculate w and determineFie. Calculate SH and SHf. Calculate SHig. Check effective stress (Seff)

Calculate S1, S2, S3 Calculate Seff Check by comparing Seff < SMYS x F

h. Check welds for fatigue Grith weld : SLh SFL x F Longitudinal weld : SHh SFL x F

i. If any check fails, modify from step b through h

Para. 4.5

Loads A carrier pipe at an uncased crossing will be subjected to

: Internal load from pressurization External loads from earth forces (dead load) and Train or highway traffic (live load).

Para. 4.6.1

A result of temperature fluctuations caused by : Longitudinal tension due to end effects Fluctuations associated with pipeline operating conditions,

unusual surface loads associated with specialized equipment

Ground deformations arising from various sources

Para. 4.6.2

External Loads a. Earth LoadThe force resulting from the weight of the overlying soil that isconveyed to the top of pipe

b. Live Load Railroad Crossing : the load from a single train Highway Crossing : the loads from two trucks traveling in

adjacent lanes

Para. 4.6.2.2

Internal Load Produced by internal pressure,p(Psi or kPa) MAOP and MOP should be used Para. 4.6.2.3Stresses a. Stresses Due to External Loads

Where :

lb/ft3 k/m3) of 0.069 lb/in3 accounts for tw/D and E

Para. 827

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or equals to 1.0

b. Stresses Due to Live Load a. Surface Live Loads External rail load

Cooper E-80 loading of w = 13.9 psi (96 kPa)

External highway load (See. Figure 6)

Single axle loading Tandem axle loading

Para. 4.7.2.2.1

b. Impact Factor (See. Figure 7) For railroad : 1.75 For highway : 1.5

Para. 4.7.2.2.2

c. Railroad Cyclic Stresses The cyclic circumferential stress (See. Figure 8) The cyclic longitudinal stress (See. Figure 9)

Para 4.7.2.2.3

d. Highway Cyclic Stresses The cyclic circumferential stress (See. Figure 10 and 14) The cyclic longitudinal stress (See. Figure 11- 13 and 15)

Para 4.7.2.2.4

c. Stresses Due to Internal Load ( ) Para. 4.7.3Limits of Calculated Stresses See. Figure 16 and 17

See Table 2Para. 4.8

Check for Allowable Stresses

(Specified by 49 Code of Federal Regulations

Part 192 or Part 195)

a. Natural Gas[() ]

b. Liquids[() ]

Para. 4.8.1

The principal stresses a. CircumferentialS1= SHe+ SH+ SHi

b. LongitudinalS2= SLEST (T2T1) + s(SHe+ SHi)

Para. 4.8.1.2

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c. RadialS3=p =MAOP orMOP (Max. Radial Stress)

Table A-3, in Annex A gives typical values for Es, vs and T.

The total effective stress (Seff)

( ) ( ) ( ) Para. 4.8.1.3Check for Fatigue Fatigue endurance limit determined from :

S-N (fatigue strength versus number of load cycles) Min. ultimate tensile strengths as given in API 5L

Para. 4.8.2a. Grith Weld The fatigue endurance limit ()= 12,000 psi (82,740 kPa)

See. Table 3

Para. 4.8.2.1

a. Railroads Crossing (See. Figure 18A and 18B) For LG5 ft (1,5m) = For LG5 ft (1,5m) = RFSLr NL SFG F

b. Highways Crossing SLh SFG F

Para. 4.8.2.1

b. Longitudinal weldsSH SFL F

(See. Table 3 )

Para. 4.8.2.2

c. Railroads Crossing (See. Figure 18A and 18B) SHr NH SFL F NH= 1.00 for single track crossing

d. Highways Crossing SHh SFL F

Para. 4.8.2.2

Orientation of Longitudinal

Welds

The optimal location of all longitudinal welds is at the

45, 135, 225, or 315 degree position with the crown at

the zero degree position

Para. 4.9Location of Girth Welds at

Railroad Crossings

LG, at least10 ft (3 m) from the centerline of the track for

a single track crossing

Para. 4.10

5. CASED CROSSINGSCarrier Pipe Installed within The material and design requirements Latest edition of ASME B31.4 or B3.1.8 Para. 5.1

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a Casing Casings may be coated or bareCasings for Crossings Suitable materials for casings New or used line pipe

Mill reject pipe Other available steel tubular goods, including longitudinally

split casings.

Para. 5.2

Minimum Internal Diameter

of Casing

The casing pipe should be at least two nominal pipe sizes

larger than the carrier pipe

Para. 5.3

Wall Thickness Bored Crossings Shown in Annex C. Para. 5.4.1 Open Trenched Crossings The requirements of 5.7 Para. 5.4.2

General The casing pipe should be : Free of internal obstructions As straight as practicable Have a uniform bedding Installed with an overbore as small as possible Steel casing pipe should be joined completely

Para. 5.5

Location and Alignment It should extend : Min. of 2 ft (0.6 m) beyond the toe of slope or base grade 3 ft (0.9 m) beyond the bottom of the drainage ditch Para. 5.6.1

Additionally for railroad crossings, the casing pipe

should extend : When casing is sealed at both ends

Min. distance of 25 ft (7.6 m) each side from centerline of

outside track

when casing is open at both endsMin. distance of 45 ft (13.7 m) each side of the centerline of the

outside track

Para. 5.6.2

Cover Railroad Crossings :a. Under track structure proper, except secondary

and industry tracks.

b. Under track structure proper for secondary andindustry tracks.

c. Under all other surfaces within the right-of-wayor from bottom of ditches.

d. For pipelines transporting HVL, from thebottom of ditches.

Minimum Cover :

a. 5.5 ft (1.7 m)b. 4.5 ft (1.4 m)c. 3 ft (0.9 m)d. 4 ft (1.2 m)

Para. 5.7.1

Highway Crossings :a. Under highway surface proper.b. Under all other surfaces within the right-of-wayc. For pipelines transporting HVL, from the

bottom of ditches

Minimum Cover :a. ft (1.2 m)b. 3 ft (0.9 m)c. 4 ft (1.2 m)

Para. 5.7.2

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Mechanical Protection Mechanical protection shall be installed

Installation Carrier pipe installed in a casing should be : Properly designed supports, insulators, or other devices, No external load will be transmitted to the carrier pipe Accomplished by building up a ring of layers of coating and

outer wrap, or by a concrete jacket.

Manufactured insulators should be uniformly spaced andsecurely fastened to the carrier pipe

Para. 5.8

Casing Seals The casing should be : Fitted with end seals at both ends It formed with a flexible material Para. 5.9

Casing Vents Vents are not required on casings Para. 5.10

One or two vent pipes may be installed, if used : D 2 in. (51 mm) Should extend 4 ft (1.2 m) above the ground surface Fitted with suitable weather caps on the top

Para. 5.10

Insulators Insulators electrically isolate the carrier pipe from thecasing

By providing a circular enclosure Para. 5.11

Inspection and Testing The section of carrier pipe inspected visually fordefects

All girth welds should be inspected by radiographicor other nondestructive methods

Para. 5.12

6. INSTALLATIONTrenchless Installation Percussive molding D < 6 in. (150 mm) Para. 6.1.1

The bored hole, Bd Bd = D Para. 6.1.2

The following provisions apply to bored, jacked, or

tunneled crossings :Bd 2 in. (51 mm) the outside diameter of the carrier pipe

(including coating)

Para. 6.1.3

Open Cut or Trenched

Installation Backfill should be placed in : layers of 12 in. (305 mm) or less (uncompacted thickness) Para.6.2.2 Casing Requirements Under Railroads, Highways,

Roads, or Streets

shown in Table 841.114B Para. 6.2.3

General Welding (See. API Standard 1104) For uncased crossings :NDT be required for girth welds within a horizontal distance of50 ft (15 m) from either the outside or inside rail and from

either the outside or inside highway pavement line.

For cased crossings:The same applies for welds within 50 ft (15 m) of the end sealsof the casing

Para. 6.3.3

Pressure Testing Accordance with 49 CFR, Part 192 or Part 195 requirements Para. 6.3.4

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Pipeline Markers and Signs API Recommended Practice 1109 Para. 6.3.5

7. RAILROADS AND HIGHWAYS CROSSING EXISTING PIPELINESAdjustment of Pipelines at

Crossings

If adjustments are required the pipeline crossing shouldbe :

Lowered Repaired Reconditioned Replaced, or Relocated

Para. 7.1

Adjustment of In-service

Pipelines

Lowering Operations Accordance with API Recommended Practice 1117 Para. 7.2.1

Split Casings When stress due to external loads of the railroad or highwaynecessitates casing of a pipeline

Para. 7.2.2

Temporary Bypasses Suitable mechanical means to isolate the section to be adjusted Para. 7.2.3

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API RP 1102 - 1993

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