13 NCAC 13 .0413 CLEARANCES

(a) All boilers and pressure vessels shall be located so that adequate space is provided for proper operation, including visibility of all gauges, for the inspection of all surfaces, tubes, waterwalls, economizers, piping, valves and other equipment, and for maintenance and repair, including replacement of tubes. Boiler clearances shall remain free of all items, including temporarily stored items, other than boiler piping and trim. Boiler piping and trim shall not impede access to the boiler.

(b) Adequate clearance for pressure vessels shall not be less than the following, or as recommended by the manufacturer for the top and sides, a minimum unobstructed clearance of 18 inches shall be provided. Clearance for the bottom shall conform to Paragraph (a) of this Rule.

(1) Boilers, except water heaters shall have a minimum unobstructed clearance of 36 inches from the top and sides of the boiler. Clearance for the bottom shall conform to Paragraph (a) of this Rule.

(2) Water heaters shall have a minimum unobstructed clearance of 18 inches from the top and sides of the boiler. Clearance for the bottom shall conform to Paragraph (a) of this Rule.

(3) Modular boilers and water heaters that require individual units to be set side by side, front to back, or by stacking, shall have minimum unobstructed clearances as recommended by the manufacturer.

(d) To facilitate entrance of a person during an inspection, boilers or pressure vessels with a manway shall have an unobstructed clearance of not less than 84 inches from the manway, unless otherwise recommended by manufacturer's installation instructions.

History Note: Authority G.S. 95‑69.11; 95‑69.14;

Eff. May 29, 1981;

Recodified from 13 NCAC 13 .0409 Eff. January 1, 1995;

Amended Eff. February 1, 2009; January 1, 1995;

Pursuant to G.S. 150B-21.3A, rule is necessary without substantive public interest Eff. July 22, 2018;

Amended Eff. November 1, 2024.