D.C. Mun. Regs. tit. 12, r. 12-E1005
Strike Section 1005 of the International Mechanical Code in its entirety and insert a new Section 1005 in the Mechanical Code in its place to read as follows:
Steel platforms . To provide access to the top of every power boiler setting, a steel platform shall be provided, reached by means of a stationary steel stairway or ladder. The platform shall be provided with a 4 inch (102 mm) high toe guard, with a steel railing not less than 36 inches (914 mm) in height, and shall have a runway not less than 30 inches (762 mm) in width, made of steel grating or other approved material.
Platform access. The stairway or ladder shall not be less than 16 inches (406 mm) in width and shall provide easy access to and from the platform. Where more than one boiler is served by the same platform, or where otherwise deemed necessary, a second stairway or ladder, remote from the first one, shall be provided.
Means of egress. Two unobstructed and accessible means of egress remote from each other shall be provided in every room housing power boilers with an aggregate capacity of 75 horsepower (56 kW) or over, or heating boilers with an aggregate capacity of 2,400,000 btu/h (703 kW) or over. Blow off pits, ash pits, alleyways, steam pipe tunnels and other places where there would be danger of personnel being trapped shall have adequate ventilation, lighting and a number of means of egress deemed adequate by the code official.
Blow-off discharge. Blow-off piping from power boilers shall not discharge directly into a sewer. A blow-off tank or sump shall be used where conditions do not provide an adequate and safe open discharge.
Blow-off tanks. Blow-off tanks shall be designed for at least 50 percent of the working steam pressure of the boiler to which it is connected and shall be built in accordance with the ASME Code. The tanks shall have a discharge connection at least 6 inches (152 mm) above the maximum water level with a water seal, a vent from the top of the tank and a cold-water connection to the top of the tank. The vent shall be routed to a safe point of discharge above the roof of the building where it is located or the roof of any adjoining building, so as not to constitute a hazard or nuisance. The vent shall be substantially supported. The design of each tank and appurtenant piping shall be submitted to the Department for approval. Tank, outlet and vent sizes shall not be less than indicated in Table 1005.5.
TABLE 1005.5 REQUIREMENTS FOR POWER BOILERS BLOW-OFF TANKS
BOILER RATING | TANK SIZE | OUTLET (inches nom.) | VENT (inches nom.) |
2 to 25 horsepower | 24 in. diameter by 36 in. long | 2 | 2 |
26 to 75 horsepower | 30 in. diameter by 48 in. long | 3 | 3 |
76 to 150 horsepower | 36 in. diameter by 54 in. long | 5 | 4 |
151 to 250 horsepower | 36 in. diameter by 60 in. long | 5 | 5 |
251 to 600 horsepower | 42 in. diameter by 66 in. long | 5 | 6 |
601 to 1,000 horsepower | 48 in. diameter by 72 in. long | 6 | 6 |
For SI: 1 inch = 25 mm, 1 horsepower = 0.7457 kW.
D.C. Mun. Regs. tit. 12, r. 12-E1005