Change is in the air when it comes to requirements for valve and rupture identification and mitigation for pipelines.
To that end, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published a Notice of Proposed Rulemaking (NPRM) that would require installation of remote-control valves (RCV), automatic shutoff valves (ASV), or equivalent technology on newly constructed and entirely replaced gas transmission pipelines, hazardous liquid pipelines, and carbon dioxide pipelines. The new rules would also establish minimum standards for identifying ruptures, initiating pipeline shut-downs and improving emergency response effectiveness.
The proposed rule responds to a directive in the Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011 and recommendations of the National Transportation Safety Board and the Government Accountability Office. Comments are due April 6.
The NPRM will require that newly constructed or entirely replaced segments of onshore gas transmission lines and hazardous liquid and carbon dioxide lines 6 or more inches in diameter be installed with ASVs, RCVs or equivalent technology.
Manual valves may be installed only upon 90-day advance notification to PHMSA with a demonstration that installing ASVs, RCVs, or equivalent technology is economically, technically, or operationally infeasible. With respect to gas transmission pipelines, PHMSA proposes to implement this requirement by amending an existing design regulation specifying spacing requirements for sectionalizing block valves. For hazardous liquid pipelines, which are not subject to existing valve spacing requirements, PHMSA proposes a new valve spacing design regulation.
The NPRM said the term “entirely replaced” means two or more contiguous miles of pipe are replaced with new pipe. The installation of ASVs, RCVs or equivalent technology would be required to satisfy new proposed rupture mitigation standards and be able to isolate a pipeline segment within 40 minutes of a rupture. The NPRM also suggests valves directly associated with or are otherwise affected by “entirely replaced” pipelines also would need to be upgraded to ASV, RCV or equivalent valve technology even if these valves are not on the replaced segment.
The NPRM proposes new rupture identification and mitigation requirements that apply to onshore gas transmission pipelines 6 or more inches in diameter constructed or entirely replaced in high consequence areas (HCA) or Class 3 or Class 4 locations and (2) onshore segments of hazardous liquid pipelines 6 or more inches in diameter constructed or entirely replaced if they could affect an HCA.
Operators of affected pipelines would be required to install rupture mitigation valves that would completely isolate a designated “shut-off” segment from all product flow, including from lateral pipelines flowing into the designated shut-off segment, within 40 minutes of identifying a rupture. Rupture mitigation valves also would be required to be capable of actuating in one of several specified methods to mitigate a rupture within 40 minutes and have certain specified monitoring and operational capabilities.
Gas transmission pipe replaced after a class location change must comply with new requirements even if pipe does not extend for 2 contiguous miles. If an operator of a gas transmission pipeline replaces pipe in order to satisfy maximum allowable operating pressure requirements following a change in class location, the operator must install ASVs, RCVs, or equivalent technology and comply with valve spacing requirements and the new rupture identification and mitigation standards. This requirement appears to apply regardless of whether the replaced pipe extends for 2 contiguous miles.
Click here for more information on the new rules.