Field Leak Testing
Certain polyethylene pressure piping systems for gathering or transporting natural or other compressed gases cannot be tested with liquid because these systems cannot tolerate even traces of liquid. However, there is a significant safety issue that can arise with pressurized gas testing compared to hydrostatic testing with a liquid, compressed gas. Failure when testing using compressed gas will release the energy applied to stress the pipe and joints as well as the energy applied to compress the gas, which can be a massive release compared to hydrostatic testing. A new ASTM International standard provides a procedure for safely conducting leakage tests of polyethylene pressure piping systems with compressed gaseous testing media.
The new standard, F2786, Practice for Field Leak Testing of Polyethylene (PE) Pressure Piping Systems Using Gaseous Media Under Pressure (Pneumatic Leak Testing), was developed by Subcommittee F17.40 on Test Methods, part of ASTM International Committee F17 on Plastic Piping Systems.
“A practice for safely testing PE pressure systems with compressed gases is needed for contractors and small gas gathering companies that may not have safe procedures for conducting compressed gas leak tests,” says William Adams, technical director and senior engineer, WL Plastics, and chairman of the task group that developed F2786. “The scope restricts the use of practice F2786 to PE pressure piping systems that cannot be filled with a liquid or cannot tolerate traces of liquids and excludes use with certain gas piping where specific testing specifications exist in codes or regulations.”
Adams notes that the task group that developed F2786 comprised domestic and international regulators, manufacturers, consultants, gas line operators and representatives of utilities. F17 welcomes interested volunteers who want to participate in the ongoing development of its standards.
Committee F17 previously developed two practices for leak testing of thermoplastic piping systems in which the use of liquid is not an issue: F1417, Test Method for Installation Acceptance of Plastic Gravity Sewer Lines Using Low-Pressure Air, and F2164, Practice for Field Leak Testing of Polyethylene (PE) Pressure Piping Systems Using Hydrostatic Pressure.
Technical Information: William I. Adams, WL Plastics, Cedar City, Utah
ASTM Staff: Robert Morgan