Hot Products
China Suppliers Factory ASME B16.5 Forged Carbon Steel RF Blind Flange for High Pressure Applications
Material Grade
●
Carbon Steel
ASTM A105
A105N
ASTM A350 LF2
LF3
ASTM A694 F42
F46
F56
F60
F65
●
Stainless Steel
ASTM A182 F304
304L
304H
316
316L
310S
317
347
904L
F51
F53
F44
●
Alloy Steel
ASTM A182 F11
F12
F5
F9
F91
F92
●
Sealing Face
RF
FF
FTJ
Frequently Asked Questions
Q
What is the difference between ASTM A105 and ASTM A105N carbon steel?
ASTM A105 is the standard specification for carbon steel forgings used in piping applications, while A105N refers to the same material that has undergone a normalizing heat treatment process. Normalizing improves the mechanical properties and grain structure of the steel, making A105N suitable for more demanding pressure and temperature conditions.
Q
What are the advantages of using ASTM A182 F316L stainless steel over F304L?
ASTM A182 F316L contains molybdenum (2–3%), which significantly enhances its resistance to pitting and crevice corrosion, especially in chloride-rich environments. F304L, while offering good general corrosion resistance and low carbon content for weldability, does not provide the same level of protection in aggressive chemical or marine environments as F316L.
Q
When should ASTM A350 LF2 or LF3 be selected instead of A105?
ASTM A350 LF2 and LF3 are low-temperature carbon and low-alloy steel forgings designed for use in piping components that must perform at sub-zero temperatures. They are impact-tested at low temperatures (LF2 at -50°F / -46°C, LF3 at -150°F / -101°C), whereas A105 is not rated for low-temperature service. Choose LF2 or LF3 when the application involves cryogenic or cold-climate conditions.
Q
What is the purpose of the different sealing face types — RF, FF, and FTJ?
The sealing face type determines how flanges mate and create a pressure-tight seal. RF (Raised Face) is the most common type, concentrating bolt load on a smaller gasket area for a strong seal. FF (Flat Face) is used when mating with flat-faced flanges, typically in lower-pressure applications. FTJ (Full-face Tongue and Groove) provides a self-aligning, highly reliable seal and is preferred in high-pressure or critical sealing applications.
Q
What makes ASTM A182 F91 alloy steel suitable for high-temperature service?
ASTM A182 F91 is a chromium-molybdenum-vanadium alloy steel (9Cr-1Mo-V) specifically engineered for high-temperature and high-pressure applications such as power generation and petrochemical plants. Its composition provides excellent creep resistance, oxidation resistance, and long-term strength retention at elevated temperatures, making it ideal for steam pipelines and pressure vessels operating above 500°C.
Q
How do duplex stainless steels like ASTM A182 F51 and F53 compare to standard austenitic grades?
ASTM A182 F51 (2205 Duplex) and F53 (Super Duplex) have a two-phase microstructure combining austenite and ferrite, which gives them roughly twice the yield strength of standard austenitic grades like 304 or 316. They also offer superior resistance to stress corrosion cracking and pitting in chloride environments. F53 (Super Duplex) provides even higher corrosion resistance than F51, making it the preferred choice for offshore, subsea, and highly corrosive chemical processing applications.