This recommended practice is intended to apply to relieving devices and their discharge systems on refinery pressure vessels and equipment designed for maximum allowable working pressure of more than 15 pounds per square inch. Steady state of flow and Newtonian fluids are assumed in flow formulas. Storage vessels covered by API Standards 2000: Guide for Venting Atmospheric and Low-Pressure Storage Tanks and pressure vessels used for transportation of petroleum products in bulk or in shipping containers are not within the scope of this recommended practice. Inasmuch as pressure-relieving devices protect a vessel only against overpressure and not against a bursting failure when exposed to fire@ means are suggested for reducing the pressure to near atmospheric pressure and for restricting the heat input. Additional information supplementing the text discussion is presented in Appendixes A through C.
API RP 520 PT I-1976 history
0000 API STD 520 PT I:2008
2000API RP 520 PT I-2000 Sizing@ Selection@ and Installation of Pressure-Relieving Devices in Refineries; Part I - Sizing and Selection (Seventh Edition)
1993API RP 520 PT I-1993 Sizing@ Selection@ and Installation of Pressure-Relieving Devices in Refineries; Part I - Sizing and Selection (SIXTH EDITION)
1990API RP 520 PT I-1990 Sizing@ Selection@ and Installation of Pressure-Relieving Devices in Refineries Part 1 - Sizing and Selection (Fifth Edition)
1976API RP 520 PT I-1976 Recommended Practice for the Design and Installation of Pressure-Relieving Systems in Refineries Part I - Design (Fourth Edition)
1967API RP 520 PT I-1967 RECOMMENDED PRACTICE FOR THE DESIGN AND INSTALLATION OF PRESSURE-RELIEVING SYSTEMS IN REFINERIES PART I-DESIGN (THIRD EDITION)
1960API RP 520 PT I-1960 Recommended Practice for the Design and Installation of Pressure-Relieving Systems in Refineries Part I - Design (Second Edition)