PDVSA ENGINEERING DESIGN MANUAL VOLUME 13–I ENGINEERING SPECIFICATION SPECIFICATION
PDVSA N
°
TITLE
PIPELINE CROSSINGS
H–201–O
1
DEC. 98
GENERAL REVISION
4
0
MAY.89
FOR APPROVAL
6
REV.
DATE
APPD.BY Alexis Arévalo
E
PDVSA, 1983
DESCRIPTION DATE
DEC. 98 APPD.BY J. E. Rojas
PAG.
Y. K.
REV.
A.A.
J.E.R.
J.G.
E.S.
APPD.
APPD.
DATE
DEC. 98
SPECIALISTS
ENGINEERING SPECIFICATION
PDVSA
PIPELINE CROSSINGS
PDVSA H –201 –O REVISION
FECHA
1
DEC. 98
Página 1 .Menú Principal
Indice manual
Indice volumen
Indice norma
Index 1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2.1 2.2
PDVSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Petroleum Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 2
3 REGULATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
4 CASED ROAD CROSSINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
5 UNCASED ROAD CROSSINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
5.1 5.2
Boring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Open Cut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 RIVER, STREAM & SWAMP CROSSINGS . . . . . . . . . . . . . . . . . . . . . 6.1 6.2 6.3
Ditching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anchoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clean–Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 EXISTING PIPELINE CROSSINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2
Cathodic Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 3
3 3 3 4
4 4
ENGINEERING SPECIFICATION
PDVSA
PIPELINE CROSSINGS
PDVSA H –201 –O REVISION
FECHA
1
DEC. 98
Página 2 .Menú Principal
1
Indice manual
Indice volumen
Indice norma
SCOPE This specification covers the minimum requirements for road (cased and uncased), river, stream and swamp, and existing pipeline crossings.
2
REFERENCES The following are to be used in conjunction with this specification when applicable:
2.1
PDVSA AI – 211 AK – 211 HA – 201 O – 201 SD – 253 H – 202 – O
2.2
American Petroleum Institute 1102
3
Site Clearance & General Earthwork Earthwork – Excavation & Backfill Cathodic Protection (Onshore) Painting Material and Application Requirements Survey Data Pipeline Anchors
Recommended Practice for Steel Pipelines Crossing Railroads and Highways.
REGULATIONS Should there be any conflict between Venezuelan laws, standards and regulations, this specification and API standards, the order of prevalences shall be as follows: 1. Venezuelan laws, standards and regulations 2. This specification 3. API RP 1102
4
CASED ROAD CROSSINGS 4.1
Pipeline crossing highways and railroads shall be cased if combined stress on the pipeline caused by external compression and internal pressure is equal or higher than the maximum allowable stresses for operating conditions. Casing shall extend beyond the toe of the road ditch backslopes and shall be installed bare.
4.2
Vents shall be installed at each end of a cased crossing. Contractor shall cut vent holes in casing pipe prior to installing carrier pipe. Vent pipe above ground shall be painted in accordance with PDVSA Specification O – 201, “Painting Material and Application Requirements ”.
ENGINEERING SPECIFICATION
PDVSA
PIPELINE CROSSINGS
PDVSA H –201 –O REVISION
FECHA
1
DEC. 98
Página 3 .Menú Principal
Indice manual
Indice volumen
Indice norma
A vent cap fabricated from the vent pipe shall be installed on all casing vents and a pipeline marker sign shall be bolted to vent cap using drilled and tapper holes provided in vent cap. Contractor shall install a cathodic test station on one vent pipe for each casing as per General Specification HE – 201, “Cathodic Protection (Onshore) ”.
5
UNCASED ROAD CROSSINGS 5.1
Boring Where possible, the crossings of uncased roads shall be installed through the road bed by boring.
5.2
Open Cut Where boring by conventional methods is rendered impossible, pipeline shall be layed on an open crossing trench throughout the road. Immediately following the installation of crossing, the trench shall be backfilled as required by the Owner ’s Representative. Backfills of road crossings shall be tamped in 150 mm (6 inches) layers. The top 150 mm (6 inches) of backfill shall be material of the same type as the original road surface. The road shall be restored to the satisfaction of the Owner ’s Representative.
6
RIVER, STREAM & SWAMP CROSSINGS 6.1
Ditching Boring
6.1.1
The right – o f– way shall be extended to the minimum width required for construction and ditching operations. The ditch shall be excavated by dragline, dredge or other suitable and approved means. The pipe may be pulled or floated into the ditch. Equipment and methods as required shall be used to keep the ditch in conformity with the established survey line regardless of the depth of excavation and the type of soil or rock encountered. Unless specified otherwise, river crossings shall be installed with a minimum 1.200 mm (48 inches) of cover over the pipe in normal soil, and a minimum of 450 mm (18 inches) of cover over the pipe in solid rock. A minimum 600 mm (24 inches) of cover over concrete weights is required in normal soil.
6.1.2
Where rock is encountered, the top of the concrete weights may not be higher than the bottom of the river. Cover shall be measured from the top of the pipe and concrete weights to the original ground elevation.
6.2
Anchoring Unless continuous concrete – weight coating is specified, concrete bolt – on or set – on weights shall be furnished and installed by Contractor on marine
ENGINEERING SPECIFICATION
PDVSA
PIPELINE CROSSINGS
PDVSA H –201 –O REVISION
FECHA
1
DEC. 98
Página 4 .Menú Principal
Indice manual
Indice volumen
Indice norma
installations, rivers, swamps or poor drainage areas, in accordance with PDVSA specification H – 202, Pipeline Anchors. The pipe shall be wrapped with 6 mm (1/4 inch) thick rockshield before installing the weights. After protective coating and concrete river weights have been applied, wooden strips shall be installed between bolt – on weights and steel cable clamped to each weight to prevent damage to the coating while the pipe is being pulled across the river or stream.
6.3
Clean–Up The banks of all streams and rivers shall be restored to their original or better condition. When required, the banks shall also be properly rip – rapped with sacks filled with soil, sand, or other suitable material and properly seeded. The beds of all rivers shall be restored to their original elevations and grade, and spoil, debris, and other obstructions interfering with normal water flow shall be removed from the crossing. Spoil removed from the ditch shall be kept within the limits of the right – o f– way and other areas provided for construction. These areas shall be properly cleaned up by Contractor following the backfilling operation.
7
EXISTING PIPELINE CROSSINGS 7.1
7.2
The proposed pipeline(s) shall cross under all foreign pipelines and shall have at least 305 mm (12 inches) of clearance between the bottom of the foreign pipeline and the top pipeline. If the depth of the existing pipeline makes it impractical to cross under the pipeline, the proposed pipeline(s) shall cross over the top of the existing pipeline provided that Owner ’s Representative approval has been previously obtained.
Cathodic Protection Cathodic protection test stations shall be installed as show on drawings and in accordance with General Specification HA – 201 “Cathodic Protection (Onshore) ”. Before any test stations are installed on a existing pipeline, the owner of that pipeline will be contacted for approval of the installation. Also, the Contractor will notify the existing pipeline owner before attaching any leads to their pipeline.
