liquid trim

[LexVader]

Hi. I am trying to figure out what a "liquid trim" is. Can some1 please help and/or let me know about a site where I can see a picture of one.

Thanks...

 

[WWTraveler]

In a relief valve it allows the blow down to be controlled. The ASME code does not address blowdown for a liquid valve but due to customer's demands a "liquid trim" was developed. Basically the nozzle ring has a different angle and the huddle champer will be different from a vapor valve. Each manufacturer will attack the problem with their own design of these two areas.

 

[xcrosby]

Liquid trim in pressure relief valves was developed to meet the ASME Section VIII capacity certification requirements at 10% overpressure. Prior to liquid trim, the same valve was used for liquids and gas. Full lift on liquids service was achieved at pressures above 10% overpressure, usually around 25%. The liquid trim assured full lift by 10% overpressure. Blowdown can be adjusted in some models. Some liquid trim valves are also certified for gas service but the blowdown is usually longer. For services where either a gas or liquid must be relieved, or for some two-phase applications the liquid trim may provide better performance if a longer blowdown on gas is acceptable.