safety valve vent silencer 3

[morojlu]

Hello Dears,

I Have some questions about Vent Silencers for Saefty Valves:

1. What is the meaning of octave band spectrum?

2. What do PWL and DIL stand for?

3. It is requested to explain me that how I can determine the size of vent pipe (briefly guidance)

Your response would be highly appreciated.

Best wishes,

 

[AxG]

1. An Octave Band split the audible spectrum into smaller bands, identifying the frequency content of the noise.

2. DIL = Dynamic Insertion Loss
(difference of two Sound Power Levels)
e.g.
the unsilenced noise level of a valve is 150dB(A)
the silenced noise level (at the silencer) is 120dB(A)
DIL = 30 dB

3.
less velocity means less noise.
As a rule of thumb you should keep the velocity (down stream of valves)below 100 m/s

for further information you should download a copy of "Glaunach's Silencer Hand Book" at

http://www.ventsilencer.com

AxG

 

[Latexman]

Did anyone else's initial thoughts on this post go like this - if the safety valve goes off so frequently that a silencer comes to mind, the process, equipment, and controls need to be examined and modified to prevent the release?

Those were my initial thoughts. I swallowed the urge to respond as such when it first posted thinking I might learn something. I did, but not so that it convinced me that adding a silence to a PSV's discharge is the right choice.

Thoughts? Mine are, "an ounce of prevention is worth a pound of cure", and "treating the symptoms" is the last resort!

Good luck,
Latexman

 

[unclesyd]

Latexman,

My thoughts exactly.
I can see and understand a silencer on a process letdown or vent valve on say a batch process that vents steam.

I don't care about using a PSV to control the process pressure to the point of needing a silencer.