API 594-2004 pdf free download

API 594-2004 pdf free download.Check Valves: Flanged, Lug, Wafer and Butt-welding.
3.3 LIMITED RATING Where the pressure-temperature rating of the valve is lim- ited as described in 3.1 the materials shall be specified by the manufacturer. Any pressure or temperature limitation shall be marked on the nameplate, as required in 7.2. 4 Design 4.1 BODY AND COVER 4.1.1 The minimum body wall thickness for various mate- rials shall be as follows: Type ‘A’ valves only: a. Gray iron: as shown in Tables 1A and 1B for Class 125 and Class 250 only. b. Ductile iron: as shown in Tables 1A and 1B for Class 150 and Class 300 only. Type ‘A’ and Type ‘B’ valves: c. Steel and chrome-moly steels per ASME B16.34, Table 1, Group 1: as shown in Tables 1A and 1B, for Classes 150, 300, 600, 900, 1500 and 2500 d. Nickel-base alloys per ASME B16.34, Table 1, Group 2 and other alloys per ASME B16.34, Table 1, Group 3: 1. For Classes 150, 300 and 600 only: as shown in ASME B16.34, Table 3. 2. For Classes 900, 1500 and 2500: as shown in Tables 1A and 1B. e. Special materials: The minimum body wall thickness for materials not covered by ASME B16.34 shall be as agreed between the purchaser and manufacturer. 4.1.2 The face-to-face dimensions shall be as follows: Type ‘A’ valves (including valves with ring-joint facings) shall con- form to those shown in Tables 2A and 2B. Type ‘B’ valves shall conform to ASME B16.10. Short pattern or special lengths are not permitted unless by agreement between pur- chaser and manufacturer. 4.1.3 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 ade- quate. 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.
4.1.8 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. 4.1.9 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 NPS 1 / 2 . After test- ing, the tapped hole shall be fitted with an ASME B16.11 or ASME B16.14 threaded solid round or hex-head plug. The test tap may require a boss to provide the minimum thread engagement, as specified in ASME B16.34. 4.1.10 For Type ‘A’ valves a tapped hole shall be provided in the body of valves which are either NPS 10 or larger, or which weigh more than 50 lb. (23 kg), 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. If an eyebolt is specified in the purchase order, it shall conform to ASME B18.15. 4.1.11 Unless otherwise specified in the purchase order, for Type ‘A’ valves the lugs of lug type valves and flanges of dou- ble-flanged type valves shall be provided with non-threaded (drilled) bolt clearance holes. 4.1.12 Butt-welding ends shall conform to the require- ments of ASME B16.25 for the bore specified for use without backing rings. 4.1.13 Conversion of a flanged end to a butt-welding end is not permitted except by agreement between the purchaser and manufacturer. 4.1.14 Type ‘B’ valves shall have a bolted cover design that meets the requirements of ASME BPVC, Section VIII, flat covers shall conform to UG 34 and dished covers shall conform to Appendix I-6. Cover and cover flanges shall be circular except NPS 2 and NPS 2 1 / 2 . Body-to-cover joint shall be flanged with a flat face (Class 150 only), raised face, tongue and groove, spigot and recess, or ring joint per ASME B16.5.