API STD 594-2017 pdf download.Check Valves: Flanged, Lug, Wafer, and Butt-welding.
1 Scope If a product is supplied bearing the API Monogram and manufactured at a facility licensed by API, the requirements of Annex A apply. This standard covers the design, material, face-to-face dimensions, pressure-temperature ratings, and examination, inspection, and test requirements for two types of check valves. — Type “A” check valves are short face-to-face as defined in Table 2 and can be: wafer, lug, or double flanged; double flange as defined in Table 3; single plate or dual plate; gray iron, ductile iron, steel, nickel alloy, or other alloy designed for installation between Classes 125 and 250 gray iron flanges as specified in ASME B16.1, between Classes 150 and 300 ductile iron flanges as specified in ASME B16.42, between Classes 150 and 2500 flanges as specified in ASME B16.5, and between Classes 150 and 900 pipeline flanges as specified in MSS SP-44 or flanges as specified in ASME B16.47 Series A. — Type “B” bolted cover swing check valves are long face-to-face as defined in 5.1.2 and can be: flanged or butt-welding ends of steel, nickel alloy, or other alloy material. End flanges shall be as specified in ASME B16.5, or ends shall be butt-welding as specified in ASME B16.25. This standard covers the following ranges: — Type “A” valves: Classes 125 and 250, 50 ≤ DN ≤ 1200 (2 ≤ NPS ≤ 48) (excluding DN 90 [NPS 3 1 / 2 ]); a) Classes 150 and 300, 50 ≥ DN ≤ 1200 (2 ≤ NPS ≤ 48)*; b) Class 600, 50 ≤ DN ≤ 1050 (2 ≤ NPS ≤ 42)*; c) Classes 900 and 1500, 50 ≤ DN ≤ 600 (2 ≤ NPS ≤ 24)*; d) Class 2500, 50 ≤ DN ≤ 300 (2 ≤ NPS ≤ 12)*; — Type “B” valves: a) Classes 150 through 1500, 50 ≤ DN ≤ 600 (2 ≤ NPS ≤ 24)*; b) Class 2500, 50 ≤ DN ≤ 300 (2 ≤ NPS ≤ 12)*. NOTE *Valve sizes DN 90 and DN 125 (NPS 3 1 / 2 and 5) are non-preferred sizes whose usage is discouraged.
The standard nomenclature for valve parts is shown in Annex C. Figure C.1, Figure C.2, Figure C.3, and Figure C.4 illustrate typical Type “A” check valves, and Figure C.5 illustrates a typical Type “B” check valve. These figures show typical designs only and are not to be construed as precluding other available designs that comply with the requirements of this standard. The only purpose of these figures is to identify part names. The construction of a valve is acceptable only when it complies with this standard in all respects. 2 Normative References The following referenced documents are indispensable for the application of this document. Unless otherwise cited by specific revision or date, the latest edition of the referenced documents (including any amendments) applies. API Standard 598, Valve Inspection and Testing ASME B1.1 1 , Unified Inch Screw Threads (UN and UNR Thread Form) ASME B1.13M, Metric Screw Threads: M Profile ASME B16.1, Gray Iron Pipe Flanges and Flanged Fittings Classes 25, 125, and 250 ASME B16.5, Pipe Flanges and Flanged Fittings ASME B16.10, Face-to-Face and End-to-End Dimensions of Valves ASME B16.11, Forged Fittings, Socket-Welding and Threaded ASME B16.14, Ferrous Pipe Plugs, Bushings, and Locknuts with Pipe Threads ASME B16.25, Buttwelding Ends ASME B16.34, Valves—Flanged, Threaded, and Welding End ASME B16.42, Ductile Iron Pipe Flanges and Flanged Fittings: Classes 150 and 300 ASME B16.47, Large Diameter Steel Flanges; NPS 26 Through NPS 60 Metric/Inch Standard
5.1.2 The face-to-face dimensions shall be as follows: — Type “A” valves (including valves with ring-joint facings) shall conform to those shown in Table 2 and Table 3. — Type “B” valves shall conform to ASME B16.10 long pattern. — For Type A or Type B valves, special lengths are only permitted by agreement between purchaser and manufacturer. 5.1.3 The purchase order shall specify for Type “A” valves whether the body type shall be wafer, lug, or double-flanged, and for Type “B” valves whether the body type shall be flanged or butt-welding. Type “A” double-flanged valves will only be supplied where nut space between flanges is adequate. End and cover flanges of steel, nickel alloy, and other alloy valves shall be integrally cast or forged with the body. However, flanges may be attached by full penetration butt-welding if agreed to by the purchaser. Flanges shall conform to ASME B16.5 or ASME B16.47, and have butt-welding ends for use without backing rings. Flanges for iron valves shall only be the integral type.