AS 1978-1977

Applies to field pressure tests that use water, liquid petroleum products, or other suitable liquids in the hydrostatic testin of steel pipelines intended to carry gas or liquid petroleum that comply with AS 1958, AS 1697 and AS 2018. The code applies to hydrostatic testing of pipelines, including mains, both before and after they have been commissioned. It would not normally be used for testing pipelines classified as Division 2 systems in AS 1697. The testing of a telescoped pipeline requires additional investigations, particularly when a volume/strain-controlled test is proposed. The Code provides for tests in which the end-point is determined either from pressure observations alone or from pressure and volume observations. To establish that a pipeline is capable of withstanding the pressure for which it is designed and is free from leaks, every pressure test program in the Code has a strength test function and a leak test function. These functions may overlap. The Code assumes that agreement on the leak tightness for each section has been reached in the test program. The agreed leak tightness is used to determine the appropriate sensitivity of an instrument for leak testing. The Code does not recommend the reverse procedure, whereby it might be assumed that 5 times an available instrument sensitivity is an appropriate leak tightness for any case. Recommendations for end-points and hold times for the strength and leak tests are given in this Code