# Oklahoma — US boiler and pressure vessel inspection requirements by state

For Oklahoma, governing body is Department of Labor, Safety Standards Division; statute citation is Oklahoma State Statutes, Title 40. Labor, Oklahoma Boiler and Pressure Vessel Law, Sections 141.0 through 141.20 and Administrative Rules 380:25; power boiler inspection interval is Power boilers and high-temperature, high-pressure boilers: Internal 1 Year, External 1 Year (under pressure); low-pressure boiler inspection interval is Low-pressure steam and vapor heating boilers: Internal 2 Years, External 1 Year. Hot-water heating and hot-water supply boilers: Internal at the discretion of the inspector, External 1 Year; pressure vessel inspection interval is Pressure vessels subject to internal corrosion: Internal 3 Years, External 3 Years. Pressure vessels not subject to internal corrosion: Internal 10 Years, External 3 Years, recorded from its source on 2026-08-05.

- **State:** Oklahoma
- **Governing body:** Department of Labor, Safety Standards Division
- **Statute citation:** Oklahoma State Statutes, Title 40. Labor, Oklahoma Boiler and Pressure Vessel Law, Sections 141.0 through 141.20 and Administrative Rules 380:25.
- **Power boiler inspection interval:** Power boilers and high-temperature, high-pressure boilers: Internal 1 Year, External 1 Year (under pressure). _(verified: appears in the quote below)_
- **Low-pressure boiler inspection interval:** Low-pressure steam and vapor heating boilers: Internal 2 Years, External 1 Year. Hot-water heating and hot-water supply boilers: Internal at the discretion of the inspector, External 1 Year. _(verified: appears in the quote below)_
- **Pressure vessel inspection interval:** Pressure vessels subject to internal corrosion: Internal 3 Years, External 3 Years. Pressure vessels not subject to internal corrosion: Internal 10 Years, External 3 Years. _(verified: appears in the quote below)_
- **Accepted inspector types:** Inspections made by insurance company inspectors may be accepted in lieu of inspections made by a department inspector, provided a photostatic copy of the inspector's National Board Certificate is furnished to the department and the inspector is authorized by the commissioner of labor.
- **Exemptions:** Pressure vessels not exceeding 15 cubic feet in volume and 250 psig. Low-pressure steam boilers, hot-water heating boilers, hot-water supply boilers, hot-water supply heaters, or pressure vessels located in private residences or in apartment houses of fewer than six family units. Pressure vessels on remote sites limited to oil- and natural gas-gathering facilities, processing plants or gas-producing lease locations.

## What the source says

> Item | Internal | External | Power boilers and high-temperature, high-pressure boilers | 1 Year | 1 Year* | Low-pressure steam and vapor heating boilers | 2 Years | 1 Year | Hot-water heating and hot-water supply boilers | ** | 1 Year | Hot-water supply heaters | *** | 2 Years | Pressure vessels, excluding those within the scope of API Inspection Code, subject to internal corrosion, and waste heat team generators | 3 Years | 3 Years | Pressure vessels not subject to internal corrosion | 10 Years | 3 Years | *Under pressure. **At the discretion of the inspector. ***Only those located in public facilities. Vessels within the scope of the API Inspection Code shall be inspected as prescribed therein. Downstream welded steam piping exceeding 15 psi requires inspection.

## Source

- https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US boiler and pressure vessel inspection requirements by state](https://referencesource.org/boiler-inspection-requirements-by-state/).