All power boilers subject to these Orders shall be equipped with at least one means for feeding water to the boiler at the maximum allowable pressure. Boilers having more than 500 square feet of water heating surface shall have at least 2 means of feeding when required by paragraph PG-59(d)(2)(g) of the Code. A water supply system may be considered as a means of feeding water to the boiler where the water pressure in the system is not less than 6 percent above the pressure at which the safety valve is set to open. Feed piping, valves, and appurtenances shall be installed as required by the Code.
Cal. Code Regs. Tit. 8, § 765