Steam Boiler International Regulations

Origins

• Local and state building authorities do not create their steam boiler regulations from scratch. Instead, they use the information from the International Mechanical Code. The International Code Council created these rules from competing national regulations when it was first established in 1997. The Council also manages other construction codes that can affect steam boilers, such as the International Building Code, the International Fire Code and The International Energy Conservation Code. Basing all rules on just one authority ensures consistent standards regardless of location and installer. Only some of the more than 12 pages of international regulations are summarized here.

Installation

• Steam boilers must be installed according to the manufacturer’s instructions, with all controls initially set, adjusted and tested by the installer. The manufacturer’s rating data, nameplate and operating instructions must be attached to the device. Unless the system consists of a single low-pressure steam boiler, it requires a shutoff valve in both the supply and return pipes. The boiler needs enough clearance on all sides to allow inspection, repair and replacement. Passageways around the utility must be at least 18 inches wide. The boiler-room floor must be noncombustible, unless the boiler is listed for combustible flooring.

Valves

• A safety valve must protect the steam boiler. It must be installed directly on the valve opening of the boiler or pressure vessel, with a relief valve that discharges using gravity. The valve must not attach to the side of a safety or relief valve connection. In addition, steam boilers also require a control that automatically stops combustion when the water level goes below the safest water level as mandated by the manufacturer. The appliance must also have a quick-opening blowoff valve that is installed in the designated opening. This valve must discharge into a safe disposal area, such as a drainage system.

Gauges

• Steam boilers need a water-gauge glass that shows the water level and a pressure gauge that shows the normal pressure for the appliance’s range of operation. The operator must also be able to see a test gauge that is connected directly to the boiler and that he can calibrate and certify. The gradations on this gauge must be between 1.5 and 4 times the maximum test pressure.