PE Pipe Technical Catalogue (PDF) - Pipelife Norge AS

Pipelife Norge ASPE CATALOGUE-SUBMARINE APPLICATIONS, PIPELIFE NORGE AS, December 2002.Next phase of work is to install the concrete weights. They are fixed to the pipeline at a certain centredistance. This distance can vary along the pipeline dependent of the calculated forces to act at aspecial depth. The weights can be installed on shore or off shore. Fig. 0.2.2.2 shows an installationwhere the concrete weights are fixed to the pipe on shore and floated out on the water using cranesor excavators. Usually the weights have rectangular shape and not round.Fig.0.2.2.2 Concrete weights are fixed to the pipelineWhen all sections are weighted they have to be fitted together by flanges or support sleeves.This work is usually done off shore supported by barges and cranes. Fig. 0.2.2.3 shows a typicalinstallation.Fig.0.2.2.3 Two pipe sections are flanged togetherWhen all pipe sections are fitted together, the pipeline is ready for the sinking process. The pipelineis equipped with blind flanges in each end. At the outmost end the blind flange is also equipped withpipes and valves for air evacuation and air filling.Before start of the sinking, the route has to be marked properly by buoys floating at the sea surface.It is also very important to listen to the local weather forecast. There should be very little wind andwaves during the sinking process.Side 9 av 84