I've got a question about the formula for estimating noise from a relief valve that is in API 521.

Has anyone done empirical testing to verify the accuracy of the estimate? I haven't been able to find anything about verification.

I wanted to use the formula to get a quick estimate of the noise produced by a pipeline blowdown valve. I believe it should at least get me a reasonable result, a blowdown is similar enough to a full open relief valve in this function.

I have heard about a NASA report that was published in 2001 called "A Reduced-Noise Gas Flow Design Guide" on here, and if anyone has a copy of the report and spreadsheet I would love to get a copy of it.

Also, if anyone has suggestions for a better way to estimate noise from a blowdown valve (reduced port ball valve, full port, plug valve, etc..) I would appreciate it!

Thanks.