Pressure Relief Valves

[otter1]

Can a PRV be installed in the horizontal position off a boiler or piping? I have seen numerous pictures of installs on a boiler installed in this position. I am being told by the inspector that it must be installed in the vertical position.

 

[puigi]

What is the application? You stated boiler or piping and did not state whether it was a power boiler or heating boiler. For ASME Section I power boilers the PRV are required to be installed in the upright position (NBIC part 1 sect. 2). If this is the intended application your AI is correct.

 

[ports394]

otter1, it somewhat depends on the kind of PRV it is. If it's the typical spring-piston style for steam.. it does need to be vertical. You don't want any odd forces on it that could make the piston stick or drag inside the PRV. It could not open when it's supposed to, or potentially get stuck open.

 

[chicopee]

what type of boiler is it? water or steam?

 

[Duwe6]

To 'legally' install a PRV other than upright, it has to be rated by the mfr for that precise position. And it has to have been tested & set in that same position. If its been set in the vertical position, it can only be used in the vertical.