Liquid service for Pilot Safety Valve

[Hansac]

Can share on experience with using Pilot SV for liquid service (boiler feed water, operating at 200 barg and 160 degC). Set pressure is 250 barg. During start-up, sometimes there are pressure spikes above 95% set pressure, due to operational issue.

I'd like to hear similar stories (successful or otherwise), in terms of maintenance, inspection, and operation.

 

[georgeverghese]

Can you describe this startup operational situation ?

 

[The Obturator]

What exactly is the valve experiencing? You say that the pressure spikes, but how is the valve responding?
Do you have a specification sheet for the valve?
Moreso, can you advise on the size, rating and model no/manufacturer?
What is the history of the application? When installed, service data - part changeouts, earlier reported issues?
Inlet piping configuration? Photographs.
What is the code of the application (ASME I, VIII? etc.).

 

[LittleInch]

Pilot valves usually get you closer to the set point before discharge.

But if the pressure is spiking above 95-98% of set pressure then you need to solve the problem (the spiking) not the valve.

Otherwise you are normalising failure.

In any well designed and operated plant the Safety Valves ( the key is in their name), should NEVER lift unless their is some sort of operational or mechanical failure ( or a fire). But if this is happening regularly on start-up then something is not right and you need to fix it. I realise this is probably not what you came here looking for, but that's how I look at it.

any lifting of a Safety Relief valve should be treated as a serious failure incident and suitable investigations and recommendations / precautions taken to prevent it happening again. Accepting it as "one of those things" leads you down dark and dangerous paths. IMHO.