Safety valves hot water closed loop systems

[cjames17]

Hi

Does anyone know why we always install safety relief valves in the vertical position? By code I know I have too, but I would like to know why.


Thanks

 

[bimr]

Just about every manufacture other than Leser state that the installation shall be vertical.

Although valves can be physically mounted horizontally, they are designed to be mounted with the stems in the vertical position. Mounting the valve in other than the upright vertical position can lead to poor valve performance with excessive seat leakage.

http://farris.cwfc.com/AboutFarris/spokes/FAQs.htm

Per API 520 I & II, it is recommended to install the relief valves vertically to avoid the possibility of stagnant liquid or liquid due to condensed vapor/gas which will result in corrosion of the relief valve parts which will affect its performance. Also it recommended is to install sloped lines instead or horizontal lines which will allow free draining of liquid.