Objectives

The Pipeline and Hazardous Materials Safety Administration (PHMSA) is finalizing regulations to improve pipeline operator responses to large-volume, uncontrolled pipeline releases that may occur during the operation of certain large-diameter (6 inches or greater) onshore natural gas transmission, and hazardous liquid (including carbon dioxide) pipelines.

Although some individual operators have installed ASVs and RCVs in response to high-profile incidents, and existing regulations require operators to evaluate risks and take preventative and mitigating (P&M) measures accordingly, the potential for unmitigated consequences of major ruptures still remains high without an enforceable standard. Sections 195.452 and 192.935 of the Pipeline Safety Regulations (PSR) require operators to implement P&M at locations that "could affect high consequence areas." One of the P&M measures is for an operator to determine the need for emergency flow restricting devices (EFRD) to protect HCAs from pipeline releases. Some of the factors used to determine the need for these types of valves are the swiftness of leak detection, shutdown capabilities, terrain, and product type. The PG&E incident and the Enbridge accident had slow response times (95 minutes and 18 hours, respectively).

The final rule requires operators installing rupture-mitigation valves (RMVs) or alternative equivalent technologies pursuant to the final rule to identify ruptures and close valves to isolate the ruptured segment as soon as practicable, not to exceed 30 minutes from rupture identification.

An RMV might be infeasible if communications and security cannot be reliably established at the valve site. RMVs also might not be feasible in areas where the right-of-way is not available for installing equipment or a power source is not available because of space limitations. Alternative equivalent technologies may be needed to meet the standard in site-specific circumstances not amenable to employing ASVs and RCVs (such as remote areas where communications capabilities are limited). Also, for natural gas pipelines in some circumstances, PHMSA will allow the expansion of valve spacing by one class location (further distance apart) to resolve this issue. For example, if a Class 3 location cannot accommodate a valve at the location required by the Class 3 spacing requirement, then an exception can be allowed that increases the spacing requirement to the Class 2 requirement and to a location in which an ASV or RCV can be accommodated.

These requirements apply to newly-constructed and entirely replaced, large-diameter (6 inches or greater) onshore gas transmission, and onshore hazardous liquid pipelines. For gas pipelines, Class 1 or Class 2 locations that have a potential impact radius (PIR) less than or equal to 150 feet are excluded.

2022 Valve Final Rule Publication Date: 10/5/2022
Effective Date: October 5, 2022 and April 10, 2023

Summary of New Valve Requirements in Table format (see regulatory text for specific requirements):