Section 408.4286. Relief valve connections.  


Latest version.

All data is extracted from pdf, click here to view the pdf.

  • (1) Relief valves shall be connected to the top of boilers, with the spindle vertical either directly to a tapped or flanged opening in the boiler, to a fitting connected to the boiler by a close nipple, to a Y-base, to a valveless water pipe between adjacent boilers,  or  to  a valveless header connecting water outlets  on  the same boiler. When a Y-base is used the inlet area shall be not less than the combined    outlet areas.

    (2) When the size of the boiler requires a relief valve larger than 4 1/2 inches diameter, 2 or more valves having the required capacity shall be used. When 2 or more valves are used on a boiler, they may be single, directly attached, or mounted on a Y-base.

History: 1979 AC.