Pipeline Safety: High Consequence Area Identification Methods for Gas Transmission Pipelines
PHMSA is issuing this advisory bulletin to remind gas transmission pipeline operators of certain previously issued guidance and provide operators with additional guidance for the identification of High Consequence Areas (HCAs) along pipeline right-of-ways. This advisory bulletin provides suggestions for accurately mapping and integrating HCA data, documenting how mapping systems are used, periodically verifying and updating their mapping systems, utilizing buffer zones (tolerances) to provide additional protection around the calculated potential impact radius (PIR) along their pipelines, and ensuring the accuracy of class locations. The bulletin emphasizes that HCA identification relies on pipeline-specific information regarding the location, size, and operating characteristics of the line, as well as the identification of structures, specified sites, and their intended usage along the pipeline right-of-way.
Hazardous Materials: Use of DOT Specification 39 Cylinders for Liquefied Flammable Compressed Gas
PHMSA is issuing this safety advisory notice to inform offerors and users of DOT Specification 39 (DOT-39) cylinders that DOT- 39 cylinders with an internal volume exceeding 75 cubic inches (in\3\) (1.23 L) should not be filled with liquefied flammable compressed gas. PHMSA maintains filling or transporting DOT-39 cylinders with an internal volume exceeding 75 in\3\ (1.23 L) is not safe.