Stainless steel integral flanged gate valve has a better performance than welded flanged type though the cost is higher a little. It can avoid the defect for the welding cracks and sand holes.
Forged steel gate valves to API 602 or BS 5352;
Inspection and Test: API 598;
End flange dimension: ASME B 16.5;
BW end dimension: ASME B 16.25.
Socket-weld dimension: ASME B 16.11.
Face to face and end to end: ASME B 16.10, Manufacturer's standard;
Pressure-temperature ratings: ASME B 16.34.
Body Materials : Carbon steels ASTM A105; Low Alloy Steels ASTM A182 Grades F5, F9, F11, F22, F9, F91; impact-tested carbon-manganese steels ASTM A350 Grades LF1, LF2, LF3, LF5; Austenitic stainless steels ASTM A182 Grades F304(L), F316(L), F310(H), F317(L), F347(H), XM-19, F44, F46, F904L, Ferritic-Austenitic Stainless Steels ASTM A182 Grades F51, F53, F55, F60 F65 etc