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

For Washington, governing body is Department of Labor and Industries, Field Services & Public Safety Division (FS & PS), Boiler Program; statute citation is Chapter 296-104 WAC and Chapter 70.79 RCW; power boiler inspection interval is 1 Year internal; 1 Year external; low-pressure boiler inspection interval is 2 Years internal; 2 Years external; pressure vessel inspection interval is 2 Years internal (when subject to corrosion); 2 Years external, recorded from its source on 2026-08-05.

- **State:** Washington _(verified: appears in the quote below)_
- **Governing body:** Department of Labor and Industries, Field Services & Public Safety Division (FS & PS), Boiler Program
- **Statute citation:** Chapter 296-104 WAC and Chapter 70.79 RCW. _(verified: appears in the quote below)_
- **Power boiler inspection interval:** 1 Year internal; 1 Year external
- **Low-pressure boiler inspection interval:** 2 Years internal; 2 Years external
- **Pressure vessel inspection interval:** 2 Years internal (when subject to corrosion); 2 Years external
- **Accepted inspector types:** Inspections made by inspectors employed by insurance companies and commissioned by the department are accepted in lieu of inspections by a department inspector.
- **Exemptions:** Boilers and pressure vessels under federal regulation or operated by any railroad; Boilers and pressure vessels located on farms and used solely for agricultural purposes; Steam boilers used exclusively for heating purposes carrying a pressure of not more than 15 psig and which are located in private residences or in apartment houses of fewer than six families; Hot-water heating boilers with a pressure of not more than 30 psi located in private residences or apartment houses of fewer than six families; Boilers and pressure vessels in cities having ordinances which are enforced and which have requirements equal to or higher than those provided for under this chapter

## What the source says

> Chapter 296-104 WAC and Chapter 70.79 RCW. RULES FOR CONSTRUCTION AND STAMPING Construction: ASME Code (Current). (Sections I, III, IV, VIII, Div. 1,2,3, X, XII, XIII). ASME CSD-1, Part CF (Current) and other jurisdictional accepted national and and international standards. Code case interpretations when accepted by the chief inspector. Standards of construction approved by the chief inspector and meeting the National Board criteria for registration of boilers, pressure vessels and other pressure-retaining items. ASME PVHO-1 (Current). Manufacturer’s Data Reports for new standard boilers and unfired pressure vessels shall be registered with the National Board. Inspection: National Board Inspection Code (Current), Part 1, Installation , Part 2, Inspection , Part 3, Repairs and Alterations , and Part 4, Pressure Relief Devices . The standard for inspection of nuclear items is ASME Section XI, current edition. National Board Certified Owner/User Organizations may choose to use API-510, current edition. Pulp and paper manufacturers may use TAPPI TIP 0402-16, 2011 edition, when requested and approved by the chief inspector. The following rule changes became effective in Washington State July 1, 2025.

## 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/).