D.C. Mun. Regs. tit. 12, r. 12-E1012
Insert a new Section 1012 in the Mechanical Code to read as follows:
Miniature boiler limitation.Miniature boiler is a power or high-temperature water boiler that does not exceed the size and pressure limits specified in its definition. Where any one of the limits specified in t he definition is exceeded, the rules for power boilers shall apply.
Clearance. Each boiler shall be located so that adequate space will be provided for the proper operation of the boiler and appurtenances, for the inspection of all surfaces and for their necessary maintenance and repair. Each miniature boiler shall have the following minimum clearances:
Feed pump. Each miniature boiler operating at a pressure in excess of 25 pounds per square inch (psi) (172 kPa) shall be provided with at least one feed pump or other approved feeding device except where the steam generator is operated with no extraction of steam (closed system).
Blow-off connection. Each miniature boiler shall be provided with a blow-off connection that shall not be reduced in size and shall be led to a safe point of discharge. Whenever, in the judgment of the boiler inspector a safe place of discharge cannot be provided, a blow-down tank shall be installed, and a 1- inch (25 mm) vent leading to a safe point of discharge shall be provided on the tank. The blow-off shall be fitted with a valve or cock in direct connection with the lowest water space practicable.
Mechanically fired boilers. Each mechanically fired miniature boiler shall be provided with an automatic low-water fuel cut-off so located as to automatically cut off the fuel supply in case the water level falls to the level of the bottom of the water glass.
Gas-fired boilers . Where miniature boilers are gas-fired, the burners used shall conform to the requirements of the Fuel Gas Code. The burner shall be equipped with an automatic fuel-regulating governor that shall be regulated by the steam pressure. This governor shall be so constructed that, in the event of its failure, there shall be no possibility of steam from the boiler entering the gas chamber or gas supply pipe. A manual stop or throttle valve shall be located in the inlet pipe ahead of the fuel-regulating governor. All applicable requirements of the Fuel Gas Code shall be satisfied.
Boiler vent installations. Each gas- fired miniature boiler shall be connected to a vent or flue, or to a chimney, extended to an approved location outside of the building. The venting arrangement shall be of approved design and in accordance with the boiler manufacturer's installation instructions.
D.C. Mun. Regs. tit. 12, r. 12-E1012