Iowa Code r. 875-91.7 - Plugging boiler tubes
This rule does not apply to tubes in headers of economizers, evaporators, superheaters, or reheaters.
(1)
General requirements.
a. Leaky tubes are replaced or
plugged.
b. Tube plugs are made of
a material that 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 are kept on site, and a copy is supplied to the
department 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.
Notes
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No prior version found.