PE Pipe Technical Catalogue (PDF) - Pipelife Norge AS

Pipelife Norge ASPE CATALOGUE-SUBMARINE APPLICATIONS, PIPELIFE NORGE AS, December 2002.The sinking speed, v, should be regulated and should not be greater than thecalculated v max (ref. A.5.3).In the outmost end there must be a valve arrangement for air release and pressure control and acompressor for air filling.The pulling force, F1, and the internal air pressure should be applied according to the calculations inchapter A.5.1 and A.5.2.The sinking speed shall be checked and recorded during sinking. If the speed is too high the internalpressure must be adjusted. The pulling force can be constant or adjusted to the water depth.Before sinking, ensure that :- all bolts are re-tightened to their final torque. This applies to bolts for the concrete weights andthe bolts for flange connections.- all concrete weights are at their correct locations/positions ; verify by measurement- all ancillary devices needed are on hand, including :- air pressure gauge, increments of 0.01 bar- water valves of suitable diameter- blind flanges fitted with air valves, 1" to 2" (in/out)- water valve (in/out)- air compressor of sufficient capacity and pressure- eventually water pump of sufficient capacity and pressureA tug boat or other vessel should be available to supply the necessary pulling force.Its engine power at full speed must be known accurately, to within 10 %.Small tug boats or other vessels may be used to provide transverse control of the floating pipeas it is positioned along the route.Experience shows that sinking of a PE pipeline is normally "a piece of cake" if the planning is good,the resources sufficient and weather conditions taken into consideration.Side 83 av 84