49 CFR § 192.629 - Purging of pipelines.

---
identifier: "/us/cfr/t49/s192.629"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 192.629 - Purging of pipelines."
title_number: 49
title_name: "Transportation"
section_number: "192.629"
section_name: "Purging of pipelines."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "D"
subchapter_name: "PIPELINE SAFETY"
part_number: "192"
part_name: "TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 185(w)(3), 49 U.S.C. 5103, 60101  and 49 CFR 1.97."
regulatory_source: "35 FR 13257, Aug. 19, 1970, unless otherwise noted."
cfr_part: "192"
---


# 192.629 Purging of pipelines.

(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.

(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.