In no case shall the maximum working pressure of an old boiler be increased to a greater pressure than would be allowed for a new boiler of the same construction.
- (a) Cast iron headers and mud drums: The maximum allowable working pressure on a water tube boiler, the tubes of which are secured to cast iron or malleable iron headers, or which have cast iron mud drums, shall not exceed one hundred sixty psig.
- (b) Pressure on cast iron boilers. The maximum allowable working pressure for any cast iron boiler, except hot water boilers, shall be fifteen psig.
(Effective August 25, 1987)