• Mount the valve in a vertical position so that the valve body is self-draining.  If a body drain port is provided, make sure it is open when required by the ASME Code.  Do not plug any bonnet vent openings.  The inlet piping should be as short as possible, with no elbows, and equal to or greater than the size of the pressure relief valve inlet connection.  This will help to limit the inlet pressure drop to 3% or less when the valve is relieving.


  • When discharge piping is connected to the valve outlet, make sure it is self-draining when a body drain port is not used.  The valve should not be connected to any discharge pipe that contains pressure before the valve opens or to any pipe where the pressure build-up is greater than 10% of the set pressure when the valve is open and relieving.


  • Discharge piping, other than a short tailpipe, must be supported by something other than the valve.  For steam service, a drip pan elbow or flexible connection between the valve and the pipe should be used to prevent excessive pipe stress, due to thermal expansion, from being imposed on the valve body.


  • For threaded valves, apply a small amount of pipe thread sealing compound to external threads only.  DO NOT put any sealing compound on the first thread or any internal threads.  To do so may cause the sealing compound to enter the valve and cause seat leakage.  Use wrench flats provided to tighten the valve to the connecting pipe.  Do not use the valve body or bonnet and do not over-tighten.  To do so may cause valve leakage.  


  • For flanged valves, use new gaskets and tighten the mounting studs evenly.

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