Notes To Purchase Forged Steel Gate Valves

1. If the purchaser needs forged steel gate valves, the purchaser is responsible for clearly sfurnishing sufficient information to permit the manufacturer to complete the order. 

2. If no exceptions to this standard are to be taken, the purchase order need only make reference to API Standard 602 and specify the items marked with in the list below. Items listed below not marked with an asterisk are options that may also be specified.

a. Valve size.
b. Class. 
c. Materials.
d. End connections, including bore for butt-welding ends.
e. Extension length for extended body. 
f. Male connection style and optional integral backing ring for extended-body valve. (made by China valve manufacturer) 
g. Body type [inside screw with rising stem (ISRS) or outside screw and yoke (OS&Y) 
h. Body-bonnet joint (bolted, union, welded, or threaded-and-seal-welded).  
i. Integral flange or flange welded to body. 
j. Flange facing finish. 
k. Bolting materials other than standard. 
l. Body-bonnet joint gasket. 
m. Trim number (other than standard), nominal trim material, and any required exceptions to options permitted by the manufacturer. 
n. Packing, including any special stem and/or packing-chamber finishes requirements. 
o. Pressure-temperature rating for bellows-seal valve other than standard.
p. Bellows features other than standard. 
q. Inspection by purchaser. 
r. Integral extension or extension welded to body.
s. Post-weld heat treatment of extension-to-body attachment welds, flange attachment welds, butt-welding stub-end attachment welds, and bonnet welds of P1 and P9 materials whose nominal wall thickness is less than or equal to  3 ⁄ 4   inch. 
3. It is the purchaser’s responsibility to specify supplementary requirements for the welds, such as the need for special heat treatment and supplementary non destructive examination of the welds.  
4. See API Standard 598 for additional items that may need to be specified, including supplementary examination, the extent of inspection by the purchaser, the inspector’s address, and the optional high-pressure closure test.

This is from China Ball Valves :Notes To Purchase Forged Steel Gate Valves