PSV Noise Attenuation Through Tailpipe
PSV Noise Attenuation Through Tailpipe
(OP)
Hi Guys. I have a PSV that will relieve 160,000 lbm/hr. Service is saturated steam of 70% quality. The PSV is located inside the plant limits. I can't move it outside the plant for a whole host of reasons.
The system design is robust and is fully designed against the need for the PSV. But, as they say, sh*t happens, and that's why the Code requires PSVs in real life. So I have to deal with the possibility of a high noise level during a relief event.
One solution is a silencer. Another soution is to pipe the PSV tailpipe/discharge pipe out of the plant to outside the plot limit and no silencer needed. My calcs show that I need to be 250' away from the plant, as the crow flies, to get the noise level down to the owner-mandated SPL (114 dBA at 3'). This of course assumes no attenuation caused by the long tailpipe. A diffuser will be installed at the end of the tailpipe to break up the velocity of the exit stream.
The question is, how much SPL attenuation will I get due to the 250' run of pipe? I have a hunch that I can get down to the required 114 dBA using less than 250' of pipe.
I searched the forum here but no luck yet. I haven't found anything in any vendor's literature yet either.
Thanks guys!!!! Pete
The system design is robust and is fully designed against the need for the PSV. But, as they say, sh*t happens, and that's why the Code requires PSVs in real life. So I have to deal with the possibility of a high noise level during a relief event.
One solution is a silencer. Another soution is to pipe the PSV tailpipe/discharge pipe out of the plant to outside the plot limit and no silencer needed. My calcs show that I need to be 250' away from the plant, as the crow flies, to get the noise level down to the owner-mandated SPL (114 dBA at 3'). This of course assumes no attenuation caused by the long tailpipe. A diffuser will be installed at the end of the tailpipe to break up the velocity of the exit stream.
The question is, how much SPL attenuation will I get due to the 250' run of pipe? I have a hunch that I can get down to the required 114 dBA using less than 250' of pipe.
I searched the forum here but no luck yet. I haven't found anything in any vendor's literature yet either.
Thanks guys!!!! Pete





RE: PSV Noise Attenuation Through Tailpipe
It is a little odd that you would worry about noise levels on a psv discharge. Should be a very infrequent event associated with some process upset.
I would use a silencer or different psv if it is truly necessary.
RE: PSV Noise Attenuation Through Tailpipe
Take a look at this link for RV info:
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Here are some links on noise:
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RE: PSV Noise Attenuation Through Tailpipe
RE: PSV Noise Attenuation Through Tailpipe
Silencers built for steam PSVs are a mature, developed technology.
Your total cost for a properly sized silencer would be less than the 250' of piping plus the systems difficulties that would occur.
Try discussing your problem with these guys..... I have had good luck.... they are practical and smart....
http://www.universal-silencer.com/pdfs/HV.pdf
Be responsible and complete this thread with details of your final decision
-MJC
RE: PSV Noise Attenuation Through Tailpipe
Me? Responsible? Just ask my wife! Pete
RE: PSV Noise Attenuation Through Tailpipe