Why PSV instead of PRV is used in lubrication oil cycle?
Why PSV instead of PRV is used in lubrication oil cycle?
(OP)
Though PSV is generally used for gaseous fluid and PRV for liquid fluid, why PSV is used in lube oil system?
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Why PSV instead of PRV is used in lubrication oil cycle?
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RE: Why PSV instead of PRV is used in lubrication oil cycle?
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RE: Why PSV instead of PRV is used in lubrication oil cycle?
RE: Why PSV instead of PRV is used in lubrication oil cycle?
The difference betweem PSV and PRV seems quite tricky. The sudden opening and proportional opening.
This is uncommon knowledge. Now, I can share it with my friends.
RE: Why PSV instead of PRV is used in lubrication oil cycle?
RE: Why PSV instead of PRV is used in lubrication oil cycle?
A standard PSV that pops fully open at set-point would tend to cause a sudden drop in oil pressure that could result in an immediate trip of the major machine that is being lubricated. So, full-flow relief valves are used instead. This allows the machine to continue running, in many cases even if an overpressure event occurs. In fact, it is standard practice to block in the running oil pump (usually a positive displacement screw pump) and force the flow to relieve through the full-flow relief valve before shutting the pump down. This allows oil pumps to be switched with little or no pressure change in the oil system and little or no risk of tripping off the big machine.
We only used PSV (“pop”) valves in oil systems where the seal oil pressure is too high to allow for the use of a full-flow relief valve.
Johnny Pellin
RE: Why PSV instead of PRV is used in lubrication oil cycle?
RE: Why PSV instead of PRV is used in lubrication oil cycle?
RE: Why PSV instead of PRV is used in lubrication oil cycle?
RE: Why PSV instead of PRV is used in lubrication oil cycle?
PSV, as implied by the "Safety" bit, are normally seen as valves which are not part of normal operation, but are there to protect or make safe an abnormal condition (overpressure, fire, maloperation) and are sized for full flow. They tend to be more of a snap on snap off design rather than modulating.
Pressure relief and pressure regulating are normally seen as valves which relieve pressure at some pre-defined set point <= Design pressure and are commonly more about controlling and regulating pressure as part of normal operation.
your lube oil system may have both - a PRV (relief or regulating) as part of the normal circuit, and a PSV in some section where overpressure or perhaps contagion from a higher pressure source could occur due to say failure of a compressor or pump seal.
Who knows? Without seeing the particular flow diagram and understanding it's purpose, all we're in danger of doing is talking about which set of initials to write on the flow diagram / P&ID....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way