Thursday, November 24, 2011

PHMSA Publishes Excess Flow Valve ANPRM

In response to a National Transportations Safety Board (NTSB) recommendation to expand the use of excess flow valves in gas service lines the Pipeline and Hazardous Material Safety Administration (PHMSA) is publishing Friday (available on line today) an advance notice of proposed rulemaking (ANPRM) (76 FR 72666-72671) seeking public comment on several issues relating to the expanded use of excess flow valves (EFVs) in gas distribution systems.


The NTSB recommendation was made on June 22, 2001 in their report on a natural gas explosion at a single family residence in South Riding, VA. Their recommendation SR P-01-2 proposed that “excess flow valves be installed in all new and renewed gas service lines, regardless of a customer's classification, when the operating conditions are compatible with readily available valves” (76 FR 72667).

With a lot of caveats PHMSA required the installation of EFVs on all new or replaced service lines serving single-family dwellings in a final rule published on December 4th, 2009 (76 FR 63934). The authority for that requirement was provided in the 2006 PIPES Act (PL 109-468), but that authority did not extend beyond single-family residences. In this ANPRM PHMSA notes that they have “broad authority under 49 U.S.C. 60102 to prescribe safety standards requiring that EFVs be installed on those lines in appropriate cases” (76 FR 72668).

An EFV is a safety device that is put into (in this case) a gas transmission line. It consists of a flow measuring device and an actuator for a valve. When the gas flow reaches a pre-set volume, the EFV shuts the valve on the line, stopping the flow of gas. The set point is calculated to be some percentage of the maximum possible flow rate through the line at some pre-determined pressure. The idea is that there is some flow rate through the line that can only be explained by a catastrophic leak and shutting off the flow of gas to the leak will limit the potential size of an accidental gas explosion.

Existing Standards

PHMSA notes that there are currently three existing technical standards for the specification, manufacturing and testing of EFVs. They also explain that the existing standards “may not be applicable to all sizes and pressure ratings of EFVs that would be needed if they were mandated for use in applications other than single family residences”. Those three standards are:

• “Manufacturers Standardization Society (MSS) SP-115-2006—Design, Performance & Test.”;

• “ASTM International (ASTM) F1802-04—Standard Test Method for Performance Testing of Excess Flow Valves.”; and

• “ASTM International (ASTM) F2138-01—Standard Specification for Excess Flow Valves for Natural Gas Service.”

If the current gaps in these standards were to be addressed by the two bodies involved PHMSA would consider incorporating these three standards by reference in the final rule if and when it is developed.

Public Comment

In order for PHMSA to complete their work on this regulation they are asking for public input on some specific areas related to the potential rule. These questions fall into four general categories:

• Technical challenges (76 FR 72670);

• Economic (Cost-Benefit) analysis (76 FR 72670);

• Technical standards (76 FR 72670); and

• Review of current industry standards (76 FR 72671).
Public comments need to be filed by February 18, 2012. They may be posted electronically to the Federal eRulemaking Portal (; Docket # PHMSA-2011-0009).

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