Pipelaying Tender-VOL II - WorleyParsons.com

EPMC SERVICES FOR REWARI – KANPUR PIPELINESPECIFICATION FOR MAJOR WATER CROSSING BY HDD5.6.3 Back reaming shall be done separately from the pipeline pulling operation. The size of the backreamedhole shall be adequate (approximately 1.5 times the pipeline diameter) to allow enoughclearance for smooth pull-back of the pipeline.5.6.4 CONTRACTOR shall be responsible for maintaining the drilled hole till such time the pipeline ispulled in.5.6.5 During pulling operation, the buoyancy of the pipeline shall be controlled by suitable approvedmethods so as to maintain the buoyancy as close as possible to zero during pull-back in order toreduce friction forces of the pipeline in the hole.Bentonite slurry of specified viscosity shall be pumped into the hole, preventing the wall from collapsingand protecting the pipeline coating.5.6.6 CONTRACTOR shall provide suitable facilities to OWNER/Consultant's personnel to witness allstages of construction.5.6.7 CONTRACTOR shall be responsible for the integrity of the corrosion coating and shall apply anynecessary approved protective coatings.Coating inspection of the pipeline after completion of pulling operation shall be made by:a) Pulling the pipe to the extent possible with normal rig set tip at the exit point;b) Excavating the adjacent portion tip to and including the first held joint.The pipeline and joint coating shall be examined visually and with holiday detectors for defect. Thelength to be inspected shall, as a minimum, be one pipe length and one joint coating. In casedamages/holidays are detected in the first pipe length/ joint, the subsequent pipe length / joint shall beexposed and coaling integrity checks shall be made be found acceptable by OWNER/CONSULTANT,the first pipe length/ joint shall be repaired and/or replaced as directed by OWNER/CONSULTANT. Ifthe coating of second pipe length/ joint is also found damaged, CONTRACTOR shall propose furthercourse of action and OWNER/Consultant's instructions shall be followed. All such works shall be doneat no extra cost to OWNER/CONSULTANT.5.6.8 Before final hydrostatic testing, CONTRACTOR shall prove the diameter of the pipeline bypassing a gauging (caliper) pig through the pipeline. The gauging pig shall have a diameter equal to95% of the nominal internal diameter or the pipe. CONTRACTOR shall supply and install all temporaryscraper launchers/ receivers and other equipment, piping and materials and consumables for thepurpose.5.6.9 CONTRACTOR shall obtain plans and full details of all existing and planned, undergroundservices from the relevant Local Authorities and be responsible for location and protection of the same.CONTRATOR shall execute the work at the crossings as per guidelines of the authorities havingjurisdiction and to the satisfaction of the OWNER/CONSULTANT.n:\513-mh-2145-rkpl\11 engineering\11.8 pipelines\06 spec\specification for major water crossing byhdd\mh2145-c000-pl-spc-0018.docMH2145-C000-PL-SPC-0018 RevA Page 11 of 15