# Internal corrosion control: Monitoring.

- **operation:** document
- **citation:** 49 CFR 192.477
- **title:** Internal corrosion control: Monitoring.
- **source type:** regulation
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** current
- **official:** true
- **published on:** Not available
- **effective on:** 2026-08-18
- **summary:** If corrosive gas is being transported, coupons or other suitable means must be used to determine the effectiveness of the steps taken to minimize internal corrosion. Each coupon or other means of monitoring internal corrosion must be checked two times each calendar year, but with intervals not excee
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- **source url:** https://www.ecfr.gov/on/2026-08-18/title-49/section-192.477
**body:**

If corrosive gas is being transported, coupons or other suitable means must be used to determine the effectiveness of the steps taken to minimize internal corrosion. Each coupon or other means of monitoring internal corrosion must be checked two times each calendar year, but with intervals not exceeding 7 1/2 months.

[Amdt. 192-33, 43 FR 39390, Sept. 5, 1978]
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