Why is pressure drop tailpipe important
Why is pressure drop tailpipe important
(OP)
The API code states that the pressure drop of the tailpipe should not exceed 10% of the set pressure.
Why is this? I want to understand what happens when the 10% is exceeded.
Is there a file of website where relieve valve are described how they work and why pressure drop is important?
Why is this? I want to understand what happens when the 10% is exceeded.
Is there a file of website where relieve valve are described how they work and why pressure drop is important?





RE: Why is pressure drop tailpipe important
RE: Why is pressure drop tailpipe important
why is chattering prevention important? IF the valve fails, wouldn't it fail open? At least the pressure is released; so overpressure is not possible.
RE: Why is pressure drop tailpipe important
Good luck,
Latexman
RE: Why is pressure drop tailpipe important
Excessive drop in inlet lines also means that the system is overpressured by the amount of the drop. Ie a relief valve set at 1000 psig and has a 40 psi drop on the inlet means the line is at 1000 when the valve is starting to open and 1140 when fully open. You can overcome this by setting the PSV at 950, but best to just get the inlet line larger or shorter.
RE: Why is pressure drop tailpipe important
Something to clarify first...
The built-up back pressure should not exceed 10% of the set pressure at 10% allowable overpressure for a conventional pressure relief valve (PSV) application.
It is not only the pressure drop of tail pipe. It include the superimposed back pressure, pressure drop on the discharge system including tail pipe.
It is not applicable to all type of PSV. The "10% rule" only applicable to conventional type PSV.
Overpressure of protected vessel, reduced capacity & instability lead to damage of PSV. Read more in "Several Impact of Backpressure on Conventional PRV"
Chattering refers to rapid and cyclic opening and closure of PSV disc in contact with seat. It damage the seat and lead to leakage and potential failure of PSV.