Hydrostatic Pressure Testing
About Hydrostatic Pressure Testing
PG&E has taken many steps to enhance the safety of our operations. As part of this effort, we are planning to conduct safety tests known as Hydrostatic Pressure Tests throughout our natural gas pipeline system. PG&E will begin performing these tests in May around various locations in the service area.
The testing involves pressurizing a section of pipe with water to a much higher level than the pipe will ever operate with natural gas, and the test will validate the safe operating pressure of the pipeline.
Hydrostatic Pressure Testing Overview
Performing a hydrostatic test involves the following steps:
- PG&E obtains all required work permits and coordinates activities with local agencies.
- Gas is temporarily provided to customers from an alternate source.
- The section of pipeline to be tested is temporarily removed from service and safely vented of all natural gas.
- The inside is mechanically cleaned prior to testing.
- The section is sealed on both ends and filled completely with water.
- The pipeline is pressurized to a specified pressure greater than normal operating pressure.
- The test pressure is held and monitored for a set period of time, typically 8 hours.
- Any pipe sections that do not meet acceptable standards during the test will be replaced with new pipe that has already passed a pressure test.
- Following a successful test, the section of pipe is emptied of water, dried thoroughly and placed back into service.
What to Expect if Hydrostatic Pressure Testing is Being Conducted in Your Area
Extensive planning takes place long before a hydrostatic pressure test is performed to minimize any inconvenience to customers and local neighborhoods. Depending on the location of staging areas at both ends of the pipe section to be tested, you may notice the following:
- Temporary traffic safety cones and/or detour signs
- PG&E and PG&E-contracted field personnel
- Testing equipment, such as above ground pipes and valves
- Machinery and support equipment, such as excavators and water tanks
In addition, depending on the location of gas venting and weather patterns, you may smell gas. This situation is safe. The pipeline is cleared of gas utilizing a safe and common technique. While gas odors are likely from the work being done nearby, safety is our top priority and we encourage any resident who has questions or concerns about the smell of gas to call us 24 hours a day at 1-800-743-5000.
PG&E has a comprehensive inspection and monitoring program to ensure the safety of its natural gas transmission pipeline system.
Hydrostatic Testing Reports
PG&E provides monthly status reports on the status of its hydrostatic testing efforts for the 152 miles of "Priority 1" pipeline.
Download the October 2011 Hydrostatic Testing Report.