On March 31, 2022, PHMSA published a final rule updating the pipeline safety regulations for both natural gas and hazardous liquid operators. This new rule modified existing regulations and introduced new regulations requiring operators to install and maintain rupture mitigation valves to help improve public safety and minimize environmental impacts of pipeline ruptures.
This new rule, which is applicable to onshore gas transmission Type A gathering lines and hazardous liquid lines with diameters of 6 inches or greater, finalized revised requirements for valve spacing, updates for maintenance and inspection, risk analysis, and emergency response.
Common to both the gas and hazardous liquid rules, PHMSA requires operators to install automatic shut-off valves (ASV) or remote-control valves (RCV) on most newly constructed or entirely replaced pipelines. PHMSA has provided a new definition for entirely replaced to mean two or more miles of new pipeline (in sum total, not continuous) in any five-mile contiguous stretch within 24 months.
PHMSA has also defined a rupture mitigation valve (RMV) as any automatic shut off or remote-controlled valve that an operator uses to minimize the volume of gas released to mitigate the consequences of a rupture. Requirements were updated for notifications of a rupture to emergency control centers or local organizations, for information sharing between operators and local officials to support a response, and to evaluate the rupture analysis and valve actions to determine their effectiveness to minimize gas releases.
Valve capabilities were also standardized by PHMSA for closure, including a 30-minute window to close from rupture identification as defined in both rule sets, flow modeling to evaluate varied operating conditions and valve operations, and maintenance requirements.
On the gas transmission side, PHMSA has updated §192.719(e) to include language codifying the requirements for operators to install RMVs in accordance with the existing spacing requirements in 192.179(a). They also specifically stated that the new RMV installation requirements are applicable to pipelines in Class 3 and 4 locations, as well as Class 2 locations that have a potential impact radius of over 150 feet.
Operators that have pipelines in locations which are constructed or entirely replaced after October 5, 2022 will need to ensure any valves installed meet the updated valve requirements in 192.634. PHMSA has also said that RMVs will need to be installed if the class location for the pipeline changes and a pipe replacement is required due to a change in class location. Operators must also evaluate shut-off segments when installing valves to minimize gas releases, and those shut-off segments must be contained between RMVs with the maximum spacing determined by the class location.
On the hazardous liquid side, PHMSA has nearly mirrored the requirements for gas pipeline regulations, with some differences. Valve installations are required on both the suction and discharge sides of a pump station to isolate the equipment and at the entrance and exit of a breakout tank storage area.
PHMSA also requires installation of RMVs along the pipeline system at different intervals than gas pipelines. Specifically, RMVs must not exceed 15 miles for segments that could affect HCAs and 20 miles for segments that could not affect HCAs. Valves must also be installed on lateral takeoffs, on each side of water crossings greater than 100’ wide from high-water mark to high water mark, water reservoirs, and on HVL pipelines at maximum distances of 7.5 miles between RMVs. Hazardous liquid operators must also evaluate shut-off segments between RMVs for inclusion of all crossovers and laterals.
Operators should start evaluating upcoming construction projects where these new rules may come into play, including any locations where it may interact with existing MAOP reconfirmation efforts, to determine what steps are necessary to ensure compliance with this rule at the earliest practicable time.
EN has a team of experts ready to support your ongoing compliance efforts. We are here to make your job easier. Contact us at 630-353-4000 or info@enengineering.com and let’s chat about how we can help you.