# -17 Closures for openings.

- **operation:** document
- **citation:** 49 CFR 179.100-17
- **title:** -17 Closures for openings.
- **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) Closures shall be of approved design and made of metal not subject to rapid deterioration by the lading. Plugs, if used, shall be solid, with NPT threads, and shall be of a length which will screw at least six threads inside the face of fitting or tank.

(b) [Reserved]
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/49-cfr-179-100-17.json
- **markdown:** https://regulus.evalyn.ai/document/49-cfr-179-100-17.md
- **app url:** https://regulus.evalyn.ai/document/49-cfr-179-100-17
- **source url:** https://www.ecfr.gov/on/2026-08-18/title-49/section-179.100-17
**body:**

(a) Closures shall be of approved design and made of metal not subject to rapid deterioration by the lading. Plugs, if used, shall be solid, with NPT threads, and shall be of a length which will screw at least six threads inside the face of fitting or tank.

(b) [Reserved]
- **truncated:** false
- **body characters:** 273