1、Flanged Steel Pressure-relief ValvesAPI STANDARD 526SEVENTH EDITION, SEPTEMBER 2017Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.Neither API nor any of APIs e
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11、tandard, “should” denotes a recommendation or that which is advised but not required in order to conform to the standard.May: As used in a standard, “may” denotes a course of action permissible within the limits of a standard.Can: As used in a standard, “can” denotes a statement of possibility or ca
12、pability.This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions conc
13、erning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein shoul
14、d also be addressed to the director.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, teleph
15、one (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org.iiiContentsPage1 S
16、cope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . 13 Terms and Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Conflicting Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Orifice Areas and Designations . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.1 General . . . . . . . . . . . . . . . . . . . .
20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.2 Determination of Orifice Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.3 Valve Selectio
21、n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.4 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、. . . . . . . . . . 37.5 Lifting Levers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37.6 Special Construction Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 . . . . . . . . . . . . . . . . . . . . . . . . 37.7 Restricted Lift Pressure-Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.2 Spring-loaded Pressure-relief Valves . . .
25、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.3 Pilot-operated Pressure-relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Inspection and Shop Tests. . . . . .
26、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59.1 Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59.2 Set
27、 Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59.3 Seat Leakage Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、. . . . . . . . . . . . . 510 Identification and Preparation for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510.1 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . 510.2 Preparation for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611 Pressuretemperature Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611.2 Temperature Ranges. . . . . . . . . . . . . . . . . .
31、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611.3 Maximum Inlet Flange Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611.4 Outlet Pressure Limit . . . . . .
32、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Annex A (normative) Pressure-relief Valve Nameplate Nomenclature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Annex B (normative) Pressure-temperature
33、 Rating Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Annex C (normative) Bellows Pressure-temperature Requested Rating Factors . . . . . . . . . . . . . . . . . . . . . . . 39Annex D (informative) Valve Selection Examples . . . . . . . . . . . . . . . .
34、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Annex E (informative) Valve Selection Example: Restricted Lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Tables1 Standard Effective Orifice Areas and Letter Designations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Spring Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Spring-loaded Pressure-relief Valves “D” Orifice f(Effective Orifice Area = 0.110 in.2) . . . . . . . . . . . . . . . 7vContentsPage4 Spring-loaded Pressure-relief Valves “E” Orifice f(Effective Orifice Area
37、 = 0.196 in.2) . . . . . . . . . . . . . . . 85 Spring-loaded Pressure-relief Valves “F” Orifice f(Effective Orifice Area = 0.307 in.2) . . . . . . . . . . . . . . . 97 Spring-loaded Pressure-relief Valves “H” Orifice f(Effective Orifice Area = 0.785 in.2) . . . . . . . . . . . . . . 118 Spring-load
38、ed Pressure-relief Valves “J” Orifice f(Effective Area = 1.287 in.2). . . . . . . . . . . . . . . . . . . . . 129 Spring-loaded Pressure-relief Valves “K” Orifice f(Effective Area = 1.838 in.2) . . . . . . . . . . . . . . . . . . . . 1310 Spring-loaded Pressure-relief Valves “L” Orifice f(Effective
39、Area = 2.853 in.2) . . . . . . . . . . . . . . . . . . . . 1411 Spring-loaded Pressure-relief Valves “M” Orifice f(Effective Area = 3.60 in.2) . . . . . . . . . . . . . . . . . . . . . 1512 Spring-loaded Pressure-relief Valves “N” Orifice f(Effective Area = 4.34 in.2) . . . . . . . . . . . . . . . .
40、 . . . . . 1613 Spring-loaded Pressure-relief Valves “P” Orifice f(Effective Area = 6.38 in.2) . . . . . . . . . . . . . . . . . . . . . 1714 Spring-loaded Pressure-relief Valves “Q” Orifice f(Effective Area = 11.05 in.2) . . . . . . . . . . . . . . . . . . . . 1815 Spring-loaded Pressure-relief Val
41、ves “R” Orifice f(Effective Area = 16.00 in.2) . . . . . . . . . . . . . . . . . . . . 1916 Spring-loaded Pressure-relief Valves “T” Orifice f(Effective Area = 26.00 in.2) . . . . . . . . . . . . . . . . . . . . 2017 Pilot-operated Pressure-relief Valves “D” Orifice d(Effective Orifice Area = 0.110
42、in.2). . . . . . . . . . . . . . 2118 Pilot-operated Pressure-relief Valves “E” Orifice d(Effective Orifice Area = 0.196 in.2). . . . . . . . . . . . . . 2219 Pilot-operated Pressure-relief Valves “F” Orifice d(Effective Orifice Area = 0.307 in.2). . . . . . . . . . . . . . 2320 Pilot-operated Press
43、ure-relief Valves “G” Orifice d(Effective Orifice Area = 0.503 in.2) . . . . . . . . . . . . . 2421 Pilot-operated Pressure-relief Valves “H” Orifice d(Effective Orifice Area = 0.785 in.2). . . . . . . . . . . . . . 2522 Pilot-operated Pressure-relief Valves “J” Orifice d(Effective Orifice Area = 1.
44、287 in.2) . . . . . . . . . . . . . . 2623 Pilot-operated Pressure-relief Valves “K” Orifice d(Effective Orifice Area = 1.838 in.2). . . . . . . . . . . . . . 2724 Pilot-operated Pressure-relief Valves “L” Orifice d(Effective Orifice Area = 2.853 in.2). . . . . . . . . . . . . . 2825 Pilot-operated
45、Pressure-relief Valves “M” Orifice d(Effective Orifice Area = 3.60 in.2) . . . . . . . . . . . . . . 2926 Pilot-operated Pressure-relief Valves “N” Orifice d(Effective Orifice Area = 4.34 in.2). . . . . . . . . . . . . . . 3027 Pilot-operated Pressure-relief Valves “P” Orifice d(Effective Orifice Ar
46、ea = 6.38 in.2). . . . . . . . . . . . . . . 3128 Pilot-operated Pressure-relief Valves “Q” Orifice d(Effective Orifice Area = 11.05 in.2). . . . . . . . . . . . . . 3229 Pilot-operated Pressure-relief Valves “R” Orifice d(Effective Orifice Area = 16.00 in.2). . . . . . . . . . . . . . 3330 Pilot-op
47、erated Pressure-relief Valves “T” Orifice d(Effective Orifice Area = 26.00 in.2). . . . . . . . . . . . . . 34A.1 PRV Nameplate Nomenclature Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35FiguresB.1 Pressuretemperature Limits to
48、be Used with Table 3 to Table 30 of This Standard . . . . . . . . . . . . . . . . 36B.2 Pressuretemperature Limits to be Used with Table 3 to Table 30 of This Standard . . . . . . . . . . . . . . . . 36B.3 Pressuretemperature Limits to be Used with Table 3 to Table 30 of This Standard . . . . . . .
49、. . . . . . . . . 37B.4 Pressuretemperature Limits to be Used with Table 3 to Table 30 of This Standard . . . . . . . . . . . . . . . . 37B.5 Pressuretemperature Limits to be Used with Table 3 to Table 30 of This Standard . . . . . . . . . . . . . . . . 38C.1 Bellows Pressure-temperature Rating Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39D.1 Bellows Pressuretemperature Rating Factor for Example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41D.2 Pressuretemperature Limits 1 for Example 3 . . .
