# Purging of pipelines.

**Citation:** 49 CFR 192.629  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

(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

## Document text

(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.

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-192.629>
- Source ID: `ecfr`
- SHA-256: `6b438fd2a5fa06c5a62e6d394ca8d95190195032d1042482c3df1fb205e33418`
- Retrieved: 2026-08-20T05:54:34.435Z
- Exported: 2026-08-24T06:14:54.443Z
- Document slug: `49-cfr-192-629`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "192",
  "section": "192.629",
  "subpart": "Subpart L—Operations",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```