Api 521 Noise Calculation

Section 5.8.10.3 provides calculations for estimating noise from a discharge pipe.  The equation uses "L", sound pressure level, which is taken from Figure 18, and based on a pressure ratio = absolute pressure upstream of relief valve/absolute pressure downstream.  The figure only shows ratios up to 10.  What is the "L" value for conditions where the PR is > 10.  For instance, 750 psi line venting to atmosphere, 764.7/14.7 is > 10.  Is the calculation no longer valid?

Hi! Did you ever come up with an answer to this? I am wondering the same thing.

Hi,

Consider the doc attached , you may find pointers.

Good luck

Breizh

Edited by breizh, 22 July 2020 - 05:46 AM.