§ 790. Permissible Tube Repair.

(a) All the tubes in a firetube boiler may be retipped, provided the tube wall thickness of the original tube is not less than ninety percent (90%) of the original thickness and the retipped ends are from new material. The new end shall be located in the tube sheet subject to the greatest heat. The circumferential welds in such tubes shall not exceed four (4) in number.

(b) Complete replacement of sections of tubes or pipe in water-tube boilers is permitted, providing the remaining tube is not less than the thickness required for the designed working pressure and the requirements of paragraph PW-41 of the Code are complied with.

(c) Bulges in tubes of water-tube boilers may be repaired when:

(1) The maximum dimension of the repaired area does not exceed the diameter of the tube or two inches (2 ”) whichever is the least.

(2) There are not more than three (3) such repairs in any one (1) tube.

(3) The tube wall adjacent to the bulge is not less than the thickness required for the designed working pressure.

(4) The requirements of paragraph PW-41 of the Code are complied with.

HISTORY

1. Amendment filed 11-2-66; effective thirtieth day thereafter (Register 66, No. 38). Approved by State Building Standards Commission.