Alloy steel flanges are important connecting components commonly used to join pipelines, valves, and other equipment. Unlike ordinary flanges, alloy steel flanges are made from high-strength, highly corrosion-resistant alloy steel materials. They offer excellent mechanical properties and corrosion resistance, making them suitable for demanding conditions involving high temperature, high pressure, and strong corrosive environments.

We specialize in the sale of a wide range of stainless steel pipe fittings, steel pipes, steel plates, flanges, bolts, and nuts. Our products are widely used across various industries, from precision machinery manufacturing and cozy home decoration to the high-end aerospace sector. With exceptional product quality and broad application adaptability, we have become a trusted choice in many fields.

In addition to offering a diverse selection of products, we also provide custom processing services tailored to specific customer requirements, ensuring that every collaboration precisely meets your expectations. Equipped with advanced production facilities and a strict quality management system, we are committed to delivering high-quality piping solutions to customers worldwide.

Feel free to contact us

Alloy Steel Flanges

Specification Chart of Alloy Steel Flange

ASTM SpecificationASTM A182
StandardsANSI/ASME B16.5, B16.48, B 16.47 Series A & B, EN-1092, BS4504, BS 10, DIN
Class and Pressure Chart150#, 300#,400#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.

Main Characteristics of Alloy Steel Flanges:

High Strength: The alloy steel material offers excellent strength and rigidity, ensuring the stability and reliability of the connection.

Durability: The addition of alloying elements enhances the overall durability and service life of the flange, especially under harsh working conditions.

Corrosion Resistance: Alloy steel can withstand long-term exposure to highly corrosive media such as acids, alkalis, and seawater without deterioration.

High-Temperature Performance: Alloy steel flanges maintain stable performance even in high-temperature environments.

Weldability: Most alloy steels used for flanges offer good weldability, making installation into piping systems more convenient.

What are the Grades of ASTM A182 Flanges?

F5 : A chromium-molybdenum alloy steel with enhanced high-temperature strength, suitable for high-temperature applications.

F9 : A chromium-molybdenum alloy steel that offers improved creep resistance and high-temperature corrosion resistance, commonly used in refineries and power plants.

F11 : A low alloy steel with enhanced creep resistance, available in three classes: Class 1, Class 2, and Class 3.

F22 : A chromium-molybdenum alloy steel known for its excellent creep strength, oxidation resistance, and corrosion resistance.

F91 : A high-strength low alloy steel featuring good toughness and high-temperature strength, suitable for power generation and petrochemical applications.

F92 : A high performance ferritic alloy steel grade designed for high temperature and high pressure applications, especially in power plants and the petrochemical industry.

Chemical Composition of ASTM A182 Alloy Steel Flanges

CHEMICALLIMITSCMnPSSiNiCrMoCb
ASTM A182 F5MIN 0.30    4.000.44 
MAX0.150.600.0300.0300.500.506.000.65 
ASTM A182 F9MIN 0.30  0.50 8.000.90 
MAX0.150.600.0300.0301.00 10.001.10 
ASTM A182 F11 CL1MIN0.050.30  0.50 1.000.44 
MAX0.150.600.030.031.00 1.500.65 
ASTM A182 F11 CL2MIN0.100.30  0.50 1.000.44 
MAX0.200.800.040.041.00 1.500.65 
ASTM A182 F11 CL3MIN0.050.30  0.50 1.000.44 
MAX0.150.600.030.031.00 1.500.65 
ASTM A182 F12 CL1MIN0.050.30    0.800.44 
MAX0.150.600.450.450.50 1.250.65 
ASTM A182 F12 CL2MIN0.100.30  0.10 0.800.44 
MAX0.200.800.400.400.60 1.250.65 
ASTM A182 F22 CL1,CL3MIN0.050.30    2.000.87 
MAX0.150.600.040.040.50 2.501.13 
ASTM A182 F91MIN0.080.30  0.02 8.000.850.06
MAX0.120.600.020.010.500.409.501.050.10
ASTM A182 F92MIN0.070.30    8.500.300.04
MAX0.130.600.020.010.500.409.500.600.09

Mechanical Property of ASTM A182 Alloy Steel Flanges

MATERIALT.S (MPA)Y.S (MPA)EL %R/A %HARDNESS
ASTM A182 F5485 min275 min20 min35 min143-217
ASTM A182 F9585 min380 min20 min40 min179-217
ASTM A182 F12 CL1415 min220 min20 min45 min121-174
ASTM A182 F12 CL2485 min275 min20 min30 min143-207
ASTM A182 F11 CL1415 min205 min20 min45 min121-174
ASTM A182 F11 CL2485 min275 min20 min30 min143-207
ASTM A182 F11 CL3515 min310 min20 min30 min150-207
ASTM A182 F12 CL1415min220min20min45min121-174
ASTM A182 F12 CL2485min275min20min30min143-207
ASTM A182 F22 CL1415min205min20min35min170
ASTM A182 F22 CL3515min310min20min30min156-207
ASTM A182 F91620min415min20min40min190-248
ASTM A182 F92620min440min20min45min269

Different Types of Alloy Steel Flanges

1. Weld Neck Flange

Weld neck flange refers to a flange with a neck and a groove on the outside of the neck, which is used for butt welding with pipes or equipment.

2. Blind Flange

Blind flange is a type of flange connection. In fact, it is a flange without a hole in the middle. It is usually fixed to the flange of the pipe or equipment by bolts, and a gasket is used between the two to achieve sealing.

3. Socket Weld Flange

Socket welding flange is a type of flange that is welded by inserting the end of the pipe into the socket hole of the flange and then performing annular fillet weld.

4. Threaded flange

Threaded flange is a non-welded flange that processes the inner hole of the flange into a pipe thread and connects it with a threaded pipe.

5. Slip On Flange

Slip on flange refers to a type of flange that is welded by putting the flange on the end of the pipe and then performing annular fillet welds on the inside and outside of the flange.

6. Lap Joint Flange

The lap joint flange is not directly welded to the pipe, but is connected to the pipe through a flanged nipple.

ASME B16.5 Alloy Steel Flange Dimension:

If you want to learn about the dimensions of ASME B16.5 alloy steel flanges, you can click the link below.

1.ASME B16.5 Weld Neck Flange Dimension

2.ASME B16.5 Blind Flange Dimension

3.ASME B16.5 Socket Weld Flange Dimension

4.ASME B16.5 Threaded Flange Dimension

5.ASME B16.5 Slip On Flange Dimension

6.ASME B16.5 Lap Joint Flange Dimension

EN 1092-1 Alloy Steel Flange Dimension:

Type 01 Flange Dimension

Type 04 Flange Dimension

Type 05 Flange Dimension

Type 11 Flange Dimension

Type 12 Flange Dimension

Type 13 Flange Dimension

Manufacturing of Alloy Steel Flanges:

The manufacturing of alloy steel flanges typically involves forging. This process shapes the heated alloy steel billet under high pressure, resulting in a dense, strong, and durable flange with excellent grain flow. Manufacturers then machine the flanges to the required dimensions and tolerances according to relevant standards like ASME B16.5 or other specific requirements. They may also apply heat treatment processes to achieve the desired mechanical properties.

When selecting alloy steel flanges, it is crucial to consider the specific application requirements, including pressure, temperature, fluid media, and relevant industry standards, to ensure the selection of the appropriate grade and type of flange for safe and efficient operation.

Advantages of Using Alloy Steel Flanges

1. High Strength and Toughness

Alloy steel flanges offer superior tensile strength and impact resistance compared to carbon steel.

2. Excellent High-Temperature Performance

Maintain mechanical properties and dimensional stability at elevated temperatures.

Suitable for boilers, heat exchangers, and power generation systems.

3. Enhanced Corrosion Resistance

Chromium, molybdenum, and other alloying elements provide resistance

4. Long-Term Durability

Resistant to wear, fatigue, and thermal degradation.

Reduces maintenance costs and downtime over time.

5. Good Weldability and Machinability

Most alloy steel grades are weldable and can be easily machined to precise specifications.Facilitates custom fabrication and easy integration into complex piping systems.

6. Versatility

Used in sectors like oil & gas, chemical processing, aerospace, nuclear, and marine.

Alloy Steel Flanges for High-Pressure Applications

Off-Shore Oil Drilling Companies

Power Generation

Petrochemicals

Gas Processing

Specialty Chemicals

Pharmaceuticals

Pharmaceutical Equipment

Chemical Equipment

Sea Water Equipment

You can Get an Offer for Products in Below Material Forms:

-Pipe and Tube (EN 10216-5, ASTM A213, ASTM A249, A312, A790,)

-Forged Fitting and Flange (ASTM A182 , ASTM A105,ASTM B564 )

-Butt Weld Fittings (ASTM A234, ASTM A403,ASTM A815)

-Round bar , Billet (ASTM A276, ASTM A479)

– Plate, Sheet, Strip(ASTM A240, EN 10028-7, A480)

-Bolting, Nuts(ASTM A193, A194, A320)