American Petroleum Institute balanced-bellows pressure relief

Figure 5-6. Back pressure sizing factor, K, for balanced-bellows pressure relief valves in vapor or gas service. (API Recommended Practice 520, Sizing, Selection and Installation of Pressure Relieving Devices in Refineries, Part 1, 5th ed., 1990. Reprinted courtesy of the American Petroleum Institute.)...

Figure 4.3 Balanced-bellows pressure relief valve. (Courtesy American Petroleum Institute, 1220 L Street, NW, Washington, D.C.)...

Figure 9-4 Backpressure correction Kb for 25% overpressure on balanced-bellows reliefs in liquid service. Source API RP 520, Recommended Practice for the Sizing, Selection, and Installation of Pressure Relieving Systems in Refineries, 6th ed. (1993), p. 35. Used by permission of the American Petroleum Institute, Washington, DC.

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