API STD 594:2004 pdf download

API STD 594:2004 pdf download.Check Valves: Flanged, Lug, Wafer and Butt-welding.
3.3 LIMITED RATING
Where the pressure-temperawre racing of the valve is limited 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 materials shall be as follows:
Type A’ valves only:
a. Gray iron: as shown in Tables IA and lB for Class 125 and Class 250 only.
h. Ductile iron: as shown in Tables IA and lB for Class 150 and Class 300 only.
Type ‘A’ and 1pc ‘13’ valves:
c. Steel and chrume-moly steels per ASME B 16.34. Table 1.
Group 1: as shown in Tables IA and lB. for Classes 150. 300. 600, 900, 1500 and 2500
d. Nickel-base alloys per ASME B 16.34. Table I, Group 2 and other alloys per ASME B 16.34. Table I, Group 3:
1. For Classes 150, 300 and 600 only: as shown in ASME
B 16.34, Table 3.
2. For Classes 900, 1500 and 2500: as shown in Tables
lAand lB.
e.Special materials: The minimum body wall thickness for materials not covered by ASME B 16.34 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 conform to those shown in Tables 2A and 2B. Type B’ valves shall conform to ASME 1116.10. Short pattern or special lengths are not permitted unless by agreement between purchaser and manufacturer.
4.t3 The purchase order shall specify for Type A valves whether the body type shall be wafer, lug or double flanged and for Type ‘H’ valves whether the body type shall be flanged or butt-welding. Type A’ double-flanged valves will only he 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 HI 6.5 and have butt-welding ends for use without hacking rings. Welding and examination shall conform to ASME B3 1.3 for Normal Fluid Service, unless otherwise specified, including qualifications for the weld procedure and welder or welding operator. The finished weld thickness shall not be less than the minimum body wall thickness. Heat treat- merit shall be performed in accordance with the material specification and shall be done prior to required valve pressure testing.
4.1.4 Type ‘A’ valves larger than NPS 24 in Classes 150, 300, and 600 shall have body-flange bolt patterns suitable for the lug or double fanged type, outside diameters suitable for
the wafer type, and gasket surface dimensions compatible with the fange standards specifed in the purchase order.
4.1.5 Flange faces with ring-joint grooves shall conform to the dimensions shown in either ASME B16.5 or ASME B16.47, as applicable.