Vent Noise Calculator

The American Petroleum Institute (API) 521 Standard on “Pressure-relieving and Depressuring Systems” provides a method to estimate the sound pressure level (Lp) of a pressure safety valve venting to atmosphere.

This vent noise calculator is based on the API 521 noise estimation method, and allows the user to estimate the sound pressure level at 30 metres, as well as at any user specified distance (within the limitations of the method) by following these steps:

  1. Calculate pressure ratio and estimate sound intensity
  2. Estimate the sound pressure level at 30 metres from the vent based on the speed of sound in the fluid (c) and fluid mass flow rate (qm)
  3. Estimate the sound pressure level at a user specified distance from the vent (Lp30)

To use the calculator, follow the steps below, providing the necessary inputs.

For more information on the API 521 standard, see the API website. Leser engineering have also provided a breakdown of the API 521 method along with the ISO 4126-9 and VDI 2713 methods – download the Leser Handbook here. For more of our online tools, see our tools room homepage, or see links to our tools on the side bar.

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Please note that this or any other calculators on the tools room are for information only. WKC Group has endeavoured to ensure that the information presented here is accurate and that the calculations are correct, but will not accept responsibility for any consequential damages, faults or human errors that may arise from the use of formulas, inventories and values.