{"operation":"document","citation":"49 CFR 192.629","title":"Purging of pipelines.","source_type":"regulation","agency":"Pipeline and Hazardous Materials Safety Administration","status":"current","official":true,"published_on":null,"effective_on":"2026-08-18","summary":"(a) When a pipeline is being purged of air by use of gas, the gas must be released into one end of the line in a moderately rapid and continuous flow. If gas cannot be supplied in sufficient quantity to prevent the formation of a hazardous mixture of gas and air, a slug of inert gas must be released","machine_formats":{"json":"https://regulus.evalyn.ai/document/49-cfr-192-629.json","markdown":"https://regulus.evalyn.ai/document/49-cfr-192-629.md"},"app_url":"https://regulus.evalyn.ai/document/49-cfr-192-629","source_url":"https://www.ecfr.gov/on/2026-08-18/title-49/section-192.629","body":"(a) When a pipeline is being purged of air by use of gas, the gas must be released into one end of the line in a moderately rapid and continuous flow. If gas cannot be supplied in sufficient quantity to prevent the formation of a hazardous mixture of gas and air, a slug of inert gas must be released into the line before the gas.\n\n(b) When a pipeline is being purged of gas by use of air, the air must be released into one end of the line in a moderately rapid and continuous flow. If air cannot be supplied in sufficient quantity to prevent the formation of a hazardous mixture of gas and air, a slug of inert gas must be released into the line before the air.","truncated":false,"body_characters":662}