Forged Carbon Steel RF Blind Flange Suppliers in China - High Quality from Factory, ASME B16.5 Standards
Material Grade
Carbon Steel
ASTM A105 / A105N, ASTM A350 LF2 / LF3, ASTM A694 F42 / 46 / 56 / 60 / 65
Stainless Steel
ASTM A182 F304/304L/304H, 316/316L, 310S, 317, 347, 904L, ASTM A182 F51, F53, F44
Alloy Steel
ASTM A182 F11 / 12 / 5 / 9 / 91 / 92
Sealing Face
RF, FF, FTJ
Frequently Asked Questions
What are the common applications for ASTM A105 and A350 LF2 carbon steel?
ASTM A105 is the standard specification for carbon steel forgings for piping applications operating at ambient and higher-temperature service. ASTM A350 LF2 is specifically designed for low-temperature service, offering excellent notch toughness down to -50°F.
What is the difference between F304 and F316 stainless steel grades?
While both are austenitic stainless steels, F316 contains molybdenum, which significantly improves corrosion resistance, especially against chlorides and pitting. F304 is the standard "18/8" stainless steel, widely used for general corrosion resistance.
When should ASTM A182 alloy steel grades like F11 or F22 be selected?
ASTM A182 alloy steels (such as F11, F12, F5, F9, and F91) are alloyed with elements like chromium and molybdenum. They are selected for high-temperature and high-pressure services because they maintain strength and resist creep at elevated temperatures.
What do the sealing face abbreviations RF, FF, and FTJ stand for?
These abbreviations refer to flange facing types: RF stands for Raised Face, which concentrates pressure on a smaller gasket area; FF stands for Flat Face, used mainly with flat gaskets on cast iron or lower-pressure connections; FTJ (often referred to as RTJ - Ring Type Joint) uses a metal ring gasket for high-pressure and high-temperature services.
What are duplex stainless steel grades F51 and F53?
F51 (Duplex 2205) and F53 (Super Duplex 2507) are duplex stainless steels that feature a mixed microstructure of austenite and ferrite. They offer twice the strength of standard austenitic stainless steels and superior resistance to stress corrosion cracking and pitting.










