Flange

A flange is a fitting used to connect two pipes. It is fitted at the end of the pipe. There are holes on the flange. Two flanges are connected tightly by bolts and sealed with a gasket. The product can be classified into threaded type and welded type.

Type 1: Flat Flange
The flat flange is suitable for the connection of steel pipeline with the nominal pressure no more than 2.5MPa. Its sealing face can be fabricated into the smooth type, male and female type, as well as the tongue-and-groove type. The smooth type flat welding flange is the most commonly used one. It is basically employed under mild medium conditions such as low pressure non-purified compressed air and low pressure circulating water.

The standard for the PN series and Calss series of flat flange is HG20592-2009 and HG20615-2009 separately.

Type 2: Slip-on Flange
The standards for the product cover HG20592-2009 (PN series), HG20615-2009 (Calss series) and GB/T9116. The neck height of the product is small, which is conducive to the stiffness and bearing capacity of the product. Compared with the weld neck product, the slip-on flange needs larger welding work and more welding rods, and it can not stand high temperature, high pressure, alternating bending as well as temperature fluctuation. However, it is still very popular, owing to its convenient mounting.

Type 3: Weld Neck Flange
The product is often called high hub flange. Its usage is to transfer the pressure of the pipe, thus reducing high stress concentration.

Type 4: Socket Welding Flange
Material
1. Carbon steel: ASTM A105, 20#, Q235, 16Mn, ASTM A350, LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694, F42, F46, F48, F50, F52, F56, F60, F65, F70
2. Stainless steel: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8
3. Alloy steel: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ, 35CrMoV, 45CrMo, etc.
Production Standard
ANSI B16.5, GB/T9117.1-2000—GB/T9117.4-200, HG20592-2009(PN series), HG20615-2009 (Calss series)

Type 5: Threaded Flange
1. Nominal Diameter: DN8-DN100
2. Working Pressure: 1.0-2.5MPa
3. Material: stainless steel, carbon steel, alloy steel
4. Usage: suitable for industrial and civil pipeline thread locking and sealing involving fire protection, coal gas, cold and hot water delivery, air conditioning, air hose, oil tube, instrument, hydraulic tube, etc.

Type 6: Blind Flange
The product has no hole in the center. It is primarily used to block off a pipeline. The form of the sealing face is diversified in types, including flat face (FF), raised face (RF), male and female face (MFM), tongue and groove face (TG) and ring joints face (RJ).

Production Material
1. Carbon steel: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70
2. Stainless steel: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8
3. Alloy steel: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/Ⅲ