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Programs

Steam Safety or Hot Water Relief Valve Installation Requirements

Safety or relief valves shall be installed at the top of the boiler with the spindle of the valve in an upright vertical position. The inlet and discharge piping shall be as short and direct as possible. Safety and relief valve set pressure and capacity are determined by data from the manufacturer’s nameplate or stamping on the boiler.

Connective piping for a boiler displaying the correct installation. The valve is shown in an upright position, the inlet pipe is below the valve and a pipe below that goes out at a bend toward the left. The discharge pipe is below the valve and goes out to the right. At the bottom of the discharge pipe there is an air gap between the pipe and the floor.

Direction of Valve

Safety or relief valves shall be installed in an upright vertical position

Inlet Piping

Safety and relief valve inlet and inlet piping shall be equal in diameter

Safety and relieve valve inlet and inlet piping diameters shall be equal or smaller than the opening or port to which it is attached on the boiler

Discharge Piping

Discharge piping shall not restrict the flow from the safety or relief valve

Discharge piping diameter shall be the same size or larger than the discharge opening of the safety or relief valve

Distance from floor or air gap no greater than 6 inches

Incorrect Installation

Safety or relief valves shall not be piped in the horizontal position as shown below

Image of valve installed horizontally with a circle and cross through – indicated that it is incorrect

Safety Labeling

Steam safety and hot water relief valves that are installed on boilers shall be identified with the ASME “V”, “HV”, or National Board “VR” Symbol.

Three logos, the first is a clover shape logo with a v in the middle. The second is a clover shaped logo with hv in the middle. The last logo is a square with vr in the middle.

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