API 594-2017 pdf free download

API 594-2017 pdf free download.Check Valves: Flanged, Lug, Wafer, and Butt-welding.
5 Design 5.1 Body and Cover 5.1.1 The minimum body wall thickness for various materials shall be as follows: — Type “A” valves only: a) gray iron: as shown in Table 1 for Class 1 25 and Class 250 only; b) ductile iron: as shown in Table 1 for Class 150 and Class 300 only. — Type “A” and Type “B” valves: a) steel and chrome-moly steels per ASME B16.34, as shown in Table 1, for Classes 150, 300, 600, 900, 1500, and 2500; b) corrosion-resistant steels per ASME B16.34, Table 1 , Group 2, and nickel-based alloys per ASME B16.34, Table 1 , Group 3, as shown in ASME B16.34, Table 3. Other wall thicknesses shall be as agreed be- tween purchaser and manufacturer. c) special materials: The minimum body wall thickness for materials not covered by ASME B16.34 shall be as agreed between the purchaser and manufacturer. 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.
5.1.3.1 Welding a flange to a valve body shall be by full penetration butt-welding. The welding procedure and the welder or welding operator shall be qualified in accordance with ASME-BPVC, Section IX. Valves having flanges attached by welding shall meet the requirements of paragraph 2.1 .6 of ASME B16.34. 5.1.3.2 Integral or other alignment rings (centering backing rings) used to facilitate welding shall be completely removed after the weld is completed. 5.1.4 Type “A” valves larger than DN 600 (NPS 24) in Classes 150, 300, and 600 shall have body-flange bolt patterns suitable for the lug or double-flanged type, outside diameters suitable for the wafer type, and gasket surface dimensions compatible with the flange standards specified in the purchase order. 5.1.5 Flange faces with ring-joint grooves shall conform to the dimensions shown in either ASME B1 6.5 or ASME B16.47 Series A, as applicable. 5.1.6 Flange-facing finishes shall be: — Type “A” valves only: Gray iron and ductile iron valves shall be finished as specified in MSS SP-6;
— Type “A” and Type “B” valves: Steel, nickel-alloy, and other alloy valves shall be finished as specified in ASME B16.5 and ASME B16.47 Series A. 5.1.7 Auxiliary connections are required only when specified by the purchaser: — Type “A” gray iron and ductile iron valves: The size, type, and location of auxiliary connections shall be the manufacturer’s standard unless otherwise agreed by the manufacturer and the purchaser. — Type “A” steel, nickel-alloy, and other alloy valves: Auxiliary connections shall comply with the requirements of ASME B16.34. The location and designation of auxiliary connections shall be the manufacturer’s standard. — Type “B” valves: For steel, nickel-alloy, and other alloy valves, auxiliary connections shall comply with the requirements of ASME B16.34. The location and designation of auxiliary connections shall be per ASME B16.34. 5.1.8 The valve may have either an integral or a removable seat ring. Sealing compounds or greases shall not be used when assembling seat rings; however, a light lubricant having a viscosity no greater than kerosene may be used to prevent galling of mating threaded surfaces. 5.1.9 Tapped test openings are permitted only if specified in the purchase order. If a tap is made in the body for testing the valve, the tap shall not be larger than DN 15 (NPS 1 / 2 ). After testing, the tapped hole shall be fitted with an ASME B16.1 1 or ASME B16.14 threaded solid round or hex-head plug. The test tap shall comply with ASME B16.34. 5.1.10 For Type “A” valves, a tapped blind hole shall be provided in the body of valves that are either NPS 10 or larger, or which weigh more than 23 kg (50 lb), for attachment of an eye bolt or equivalent lifting device. The hole shall be tapped with a coarse (UNC) Class 2B thread, conforming to ASME B1.1 .