Pressure testing of pipelines

The purpose of pressure testing a pipeline system is to ensure that the system can be operated safely. The pressure test gives confidence that the system as constructed/installed is suitable for its operational requirements. A system pressure test also demonstrates the integrity of all the components, including pipes, joints and fittings. Pipes and fittings should have been manufactured such that they can withstand the system test pressures. However, they may be defective, have been damaged in transit or during installation, could be incorrectly installed, have inherent material defects or defects caused during manufacturing, and so on. Other components of the pipeline system (e.g. flanges, gaskets, welds, bedding and pipe support, thrust restraint) will have been constructed and installed on site and the pressure test provides assurance that the system as provided is safe and correctly constructed (Figure 29.1).