Subsea pipeline system after the completion of the laying should be pressure tested. Pressure test is the final check the pipe system, including strength test and leak test, the purpose is to demonstrate the piping system being tested is not leak tight and has structural strength required to withstand the design pressure of a predetermined safety requirements. Pressure testing shall be approved procedures. Pressure test piping system should range from pigging ball transmitter to the receiver section pipes, pressure test should be in the pipeline system fully installed and the pipeline protection (such as embedded or overlay) after completion.
For seal piping system should be blind or blind flange. When installing, first check the flange sealing surface is clean, smooth finish is appropriate, mechanical damage and corrosion damage. Check the gaskets and fasteners form, materials, dimensions and quality compliance requirements. When installing the gasket, should the two flange sealing face of potential, distance is not too large, the gasket in the correct position, tighten the bolts evenly and orderly, keeping only be used to compress the gasket bolt load it can not be used to draw flange. The application of a torque wrench to tighten the bolts have required preload. When the tube end sealing directly, should take the form of blind welding, blind is commonly used in a pressure pipe conduit elements, strength design safety factor of at least 2 blind.
Before pressure test work, to deal with the integrity of the pipeline system for inspections of all piping systems and attachments in accordance with the requirements of design drawings completed all pipeline welding work completed and qualified non-destructive testing. Piping system before pressure test, generally carried out qualified pigging, so before sealing of the pipeline system, the pipeline has been filled with water (sea, preservatives, fluorescent agents and marine growth inhibitors, etc.).
Post time: Sep-27-2021