Iowa Admin. Code r. 875-91.8

Current through Register Vol. 47, No. 5, September 4, 2024

Rule 875-91.8 - Plugging boiler tubes

This rule does not apply to tubes in headers of economizers, evaporators, superheaters, or reheaters.

(1)General requirements.

a. Leaky tubes shall be replaced or plugged.

b. Tube plugs shall be made of a material which is compatible with the material of the boiler tube being plugged and shall be welded into place or manufactured to be expanded into the tube sheet or drum.

c. The maximum number of tubes that may be plugged shall be the lesser number specified by the OEM or an engineer experienced in boiler design.

d. Documentation of the maximum number of tubes that may be plugged shall be kept on site, and a copy shall be supplied to the division of labor services by either mail or email.

(2)Fire tube boilers.

a. A tube that is adjacent to a plugged tube shall not be plugged.

b. All plugged boiler tubes shall be replaced prior to the next required certificate inspection.

(3)Water tube boilers, unfired boilers, or process steam generators. Water wall tubes that form a separation wall between products of combustion and the outside atmosphere or a separation of the gas passes in a multiple gas pass boiler shall not be plugged.

Iowa Admin. Code r. 875-91.8

Amended by IAB October 20, 2021/Volume XLIV, Number 8, effective 11/24/2021

Amended by IAB November 30, 2022/Volume XLV, Number 11, effective 1/4/2023