Installation of Safety relief valves on Vessels / Piping 1

[Isla]

Can any one provide me proper resoning why a Safety relief valve is mounted horizontal

CROSBY recommends to mount safety valve with spindle vertical for proper functionality.

 

[pennpiper]

My first response is, there is no reason or justification for mounting a safety valve, PSV or TSV with the stem in the horizontal. It is something that is simply not done by a properly trained and well experienced and responsible piping designer.

However, you might give us more information on this question.
Why do you ask this question?
What is the inlet/outlet size of the safety valve?
Is there other valving involved?
What is the commodity in the line?
Other?

 

[Isla]

Thanks for quick response Mr pennpiper
There is a Safety Relief valve mounted on one of the plunger pumps ( service wash water injection system). The safety relief is not functioning properly. I fully agree with you It is not good engg practiuce to mount a safety relief horizonatal
The inlet size is 1 1/2" and out let 2"

I don't understand why this particular safety relief is mounted horizontal??????

 

[abeltio]

these valves are mounted with a vertical stem because all the test benches used for calibration keep the valve in the vertical position...

i.e. the setting includes the weight of the trim, spring etc...

for big valves this would create a significant difference between the shop setting and the field effective setting.

also... when installed horizontall they really look awful P



saludos.
a.

 

[JJPellin]

There is another reason that I don't like to see relief valves mounted horizontally. We have a critical pump that has two relief valves on the lube oil system that are mounted horizontally. For these particular valves, the inlet and outlet are the same size. When pipe fitters removed these valves for routine maitenance, they were reinstalled vertically since that is what is most common. A relief valve hooked up backwards will not work. In our case, this was not very serious since it was just a lube oil system. In a more critical application, operating with no overpressure protection could have had very serious consequences.

 

[jte]

Could there be some confusion with the block valve to the safety valve rather than the safety valve itselt? We typically mount our block valves for safety valves with the stem horizontal. That way if the stem breaks we don't drop the gate and block the flow to the safety valve. But the safety valves are typically stem up...

jt

 

[proinwv2]

Consider that the loading is changed, by adding "side forces", although they are small as compared to fluid loads. Even so, don't ignore this.

What about drainage or freezing?

Question the manufacturer's engineering staff, not the rep., about your application.

Paul Ostand

http://www.ostand.com

 

[CHD01]

Normally, you will never and should never see a relief valve mounted horizontally. In this case, it sounds as if the relief valve you speak of was provided as an "internal" relief from the discharge to the suction side of the pump by the pump manufacturer. This is done for P.D. pumps (Viking is one) handling viscous materials (i.e. - polymers for one). Normally the plant would not accept such an internal valve for protection of pipe systems connecting to the pump; except for fractional HP non-flammable and non-hazardous services. The internal relief valve is not a certified device; and it is difficult to test and verify proper operation.

The more you learn, the less you are certain of.