scope:

This guide presents recommended practices applicable to pressure-relieving and vapor depressuring systems. The information provided herein is designed to aid in the selection and type of system most appropriate for the risks and circumstances involved in the various installations. It is intended to supplement the practices set forth in API RP 520 [1]¹ for establishing a basis of design.

This publication provides guidelines for examining the principal causes of overpressure, for the determining individual relieving rates, and for selecting and designing disposal systems, which include such component parts as vessels, flares, and vent stacks.

Piping information pertinent to pressure-relieving systems is presented in 5.4.1, but the actual piping is to be designed in accordance with ANSI/ASME B31.3 [2] or other applicable codes.

¹ Numbers in brackets refer to references in 1.3.