China Suppliers Factory ASME B16.5 Class 150 Carbon Steel Lap Joint Flange - High Quality Forged Steel Flanges
Material Grade
Carbon Steel
ASTM A105 / A105N
ASTM A350 LF2 / LF3
ASTM A694 F42 / 46 / 56 / 60 / 65
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
ASTM A182 F51, F53, F44
Alloy Steel
ASTM A182 F11 / 12 / 5 / 9 / 91 / 92
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Sealing Face
RF | FF | FTJ
Frequently Asked Questions
Q
What is the difference between ASTM A105 and ASTM A105N?
ASTM A105N refers to the normalized condition of A105 carbon steel forgings. The "N" indicates that the material has undergone a normalizing heat treatment process, which improves mechanical properties such as toughness and uniformity of microstructure.
Q
When should I choose ASTM A350 LF2 over ASTM A105?
ASTM A350 LF2 is specifically designed for low-temperature service applications. It is impact-tested at sub-zero temperatures, making it suitable for cryogenic or cold-climate environments where A105 may not meet toughness requirements.
Q
What is the advantage of using 316L stainless steel over 304L?
ASTM A182 F316L contains molybdenum (2–3%), which provides superior resistance to pitting and crevice corrosion, especially in chloride-containing environments such as seawater or chemical processing. F304L, while corrosion-resistant, lacks this additional protection.
Q
What applications are alloy steel grades such as F11 and F91 used for?
ASTM A182 alloy steel grades like F11, F12, F91, and F92 are engineered for high-temperature and high-pressure service. They are commonly used in power generation, petrochemical, and refinery applications where elevated temperature strength and creep resistance are critical.
Q
What is the difference between RF, FF, and FTJ sealing faces?
RF (Raised Face) is the most common type, used with soft gaskets for general service. FF (Flat Face) is used when connecting to cast iron or other brittle flanges to prevent bending stress. FTJ (Female & Tongue and Groove Joint) provides a more precise seal by confining the gasket, suitable for higher-pressure or hazardous fluid applications.
Q
Is 904L stainless steel suitable for highly corrosive environments?
Yes. 904L is a high-alloy austenitic stainless steel with high nickel, chromium, and molybdenum content. It offers excellent resistance to strong acids including sulfuric acid, phosphoric acid, and acetic acid, making it ideal for aggressive chemical processing and marine environments.









