# Purging of pipelines.

- **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:** Not available
- **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.

(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