API Std 608-2020 pdf download.Metal Ball Valves—Flanged, Threaded, and Welding Ends.
1 Scope 1.1 This standard specifes the requirements for metal ball valves suitable for petroleum, petrochemical, and industrial applications— corresponding to the nominal pipe sizes in ASME B36.10M—that have: — fanged ends in sizes DN 15 through DN 600 (NPS 1 / 2 through NPS 24); — butt-welding ends in sizes DN 15 through DN 600 (NPS 1 / 2 through NPS 24); — socket-welding ends in sizes DN 8 through DN 50 (NPS 1 / 4 through NPS 2); and — threaded ends in sizes DN 8 through DN 50 (NPS 1 / 4 through NPS 2) 1.2 This standard applies to metal ball valves with pressure classes as follows: — fanged ends in Classes 150, 300, and 600; — butt-welding ends in Classes 150, 300, 600, and 800; — socket-welding ends in Classes 150, 300, 600, and 800; — threaded ends in Classes 150, 300, 600, and 800. 1.3 This standard establishes requirements for bore sizes described as: — full bore; — single reduced bore; — double reduced bore. 1.4 This standard applies to foating (seat-supported) ball (Figure C.1) and trunnion ball valve designs (Figure C.2). These fgures are to be used only for the purpose of establishing standard nomenclature for valve components—other foating and trunnion designs also exist. 1.5 This standard establishes additional requirements for ball valves that are otherwise in full conformance to the requirements of ASME B16.34, Standard Class. 1.6 If product is supplied bearing the API Monogram and is manufactured at a facility licensed by API, the requirements of Annex A shall apply. 1.7 Trunnion ball valves equipped with double piston efect seats are outside of the scope of this standard. 2 Normative References The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda) applies. API Standard 598, Valve Inspection and Testing API Standard 602, Gate, Globe,
API Standard 607, Fire Test for Quarter-turn Valves and Valves Equipped with Nonmetallic Seats API Standard 641, Type Testing of Quarter-turn Valves for Fugitive Emissions ASME B1.1, Unifed Inch Screw Threads (UN and UNR Thread Form) ASME B1.20.1, Pipe Threads, General Purpose (Inch) ASME B16.5, Pipe Flanges and Flanged Fittings: NPS 1 / 2 Through 24 Metric/Inch Standard ASME B16.10, Face-to-Face and End-to-End Dimensions of Valves ASME B16.11, Forged Fittings, Socket-welding and Threaded ASME B16.20, Metallic Gaskets for Pipe Flanges ASME B16.25, Buttwelding Ends ASME B16.34, Valves—Flanged, Threaded, and Welding End ASME B18.2.2, Nuts for General Applications: Machine Screw Nuts, Hex, Square, Hex Flange, and Coupling Nuts (Inch Series) ASME B36.10M, Welded and Seamless Wrought Steel Pipe NACE MR 0103, Petroleum, petrochemical and natural gas industries—Metallic materials resistant to sulfde stress cracking in corrosive petroleum refning environments 3? Terms? and? Defnitions For the purposes of this document, the following defnitions apply. 3.1 Class An alphanumeric designation that is used for reference purposes relating to valve pressure-temperature capability, taking into account valve material mechanical properties and valve dimensional characteristics. It comprises the word “Class” followed by a dimensionless whole number. The number following the word “Class” does not represent a measurable value and is not used for calculation purposes except where specifed in this standard. The allowable pressure for a valve having a class number depends on the valve material and its application temperature is found in tables of pressure-temperature ratings. 3.2 DN An alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters “DN” followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate.
3.5 trim Internal metal parts of the valve, including ball, stem, trunnion (if it is not part of the pressure boundary), metal seats, and seat retainers (see Annex C). 3.6 UN The various constant-pitch series (UN/UNR) with 4, 6, 8, 12, 16, 20, 28, and 32 threads per inch that ofer a comprehensive range of diameter-pitch combinations for those purposes where the threads in the coarse-, fne-, and extra-fne-thread series do not meet the particular requirements of the design. 3.7 UNC The coarse-thread series (UNC/UNRC) generally used for the bulk production of screws, bolts, and nuts. 3.8 valve-bidirectional Type of valve having shutof capability in both directions. 3.9 valve-unidirectional Type of valve designed for sealing only in one direction. 4 Pressure-temperature Ratings 4.1 Valve Rating The valve pressure-temperature rating shall be the lesser of the shell rating or the seat and seal rating. 4.2 Shell Rating The valve shell pressure-temperature rating shall be the rating for the shell material as listed for Standard Class in ASME B16.34. The valve shell pressure/temperature ratings for intermediate Class 800 valves shall be as shown in Table 2a, Table 2b, Table 2c, Table 2d, Table 2e, and Table 2f of API 602 (2016). 4.3 Seat and Seal Rating 4.3.1 Seat Ratings for PTFE and R-PTFE Valves employing polytetrafuoroethylene (PTFE) or modifed PTFE seats and valves employing reinforced polytetrafuoroethylene (R-PTFE) or modifed R-PTFE seats shall have pressure-temperature ratings equal or higher than the values shown in Table 1 and Table 2.