# -4 Safety relief devices and pressure regulators.

- **operation:** document
- **citation:** 49 CFR 179.103-4
- **title:** -4 Safety relief devices and pressure regulators.
- **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) Safety relief devices and pressure regulators must be located on top of the tank near the center of the car on a nozzle, mounting plate or recess in the shell. Through or stud bolts, if used, must not enter the tank.

(b) Metal guard of approved design must be provided to protect safety relief d
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/49-cfr-179-103-4.json
- **markdown:** https://regulus.evalyn.ai/document/49-cfr-179-103-4.md
- **app url:** https://regulus.evalyn.ai/document/49-cfr-179-103-4
- **source url:** https://www.ecfr.gov/on/2026-08-18/title-49/section-179.103-4
**body:**

(a) Safety relief devices and pressure regulators must be located on top of the tank near the center of the car on a nozzle, mounting plate or recess in the shell. Through or stud bolts, if used, must not enter the tank.

(b) Metal guard of approved design must be provided to protect safety relief devices and pressure regulators from damage.

[Amdt. 179-10, 36 FR 21348, Nov. 6, 1971]
- **truncated:** false
- **body characters:** 386