Characteristics of butt welding flanges

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2023-06-13 09:58

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Butt welding flanges can be connected to the pipe to maintain the sealing performance of the pipe. The butt-welding flange is easy to replace the pipe section, easy to remove and check the pipe condition, and easy to seal the pipe section made of carbon steel. The flange is the connection of two large diameter pipes. The device is also called a carbon steel flange and usually consists of two flange parts and several fastening bolts.

Carbon steel flanges are made of carbon steel. Low carbon steel has good plasticity and low strength. Adding the right amount of carbon will harden, and plasticity will reduce strength. Flanged connections may need to withstand higher tensile, compression, torsion and shear strengths. Therefore, welding flange is a better choice.

Welding flange use matters needing attention:

1. In order to prevent intergranular corrosion caused by heating the welded flange, the butt current should not be too large, about 20% smaller than the carbon steel electrode, the arc should not be too long, the intermediate layer should be cooled quickly, and the weld should be narrow. The electrode should be kept dry, the titanium calcium type should be dried at 150 ℃ for 1 hour, and the low hydrogen type should be dried at 200-250 ℃ for 1 hour (can not be dried repeatedly, otherwise the coating is easy to crack and peel off) to prevent the electrode coating from adhering to oil and other dirt, so as to avoid increasing the carbon content of stainless steel and butt welding flange in the weld, which will affect the weld quality.

2. In the butt welding process of butt welding flange, repeated heating will precipitate carbides, thereby reducing corrosion resistance and mechanical properties. After the chrome stainless steel welding flange is hardened, the American standard flange is large and easy to crack. The same type of chromium stainless steel electrode (G202,G207) for butt welding, should be more than 300 times and more than 700 times of preheating slow cooling.

PRE

Applicable scope and purpose of welding flange

Characteristics and sealing principle of flat welding flange

PRE

Applicable scope and purpose of welding flange

Characteristics and sealing principle of flat welding flange

2023-06-13

Stainless steel flanges are flanges that extend steel pipes, pipe fittings, etc. into the flanges and are connected to equipment or pipelines through fillet welds. The inner hole on one side of the flange is provided with a welding boss, and the welding boss is provided with an inner hole. The inner hole communicates with the inner hole in the center of the flange, and there is elasticity between the flange and the welding boss. The two top surfaces of the elastic ring are respectively combined with the flange and the welding boss. There are many screw holes on the flange. The screw holes are symmetrically distributed around the center of the flange. The stainless steel flange is made of stainless steel, followed by a polyethylene plastic layer, a rubber layer and a PVC layer. Here we take a look at the use of stainless steel flange precautions. 1. In order to prevent corrosion between eyes caused by heating of stainless steel flanges, the welding current should not be too large, about 20% less than carbon steel electrode, the arc should not be too long, the cooling speed is between the number of layers, and the narrow bead effect is better.

Advantages and disadvantages of flat welding flange

2023-06-13

Flat welded flanges are mainly used for gas valves and natural gas pipelines. Because the short neck can improve the rigidity and carrying capacity of the flange. Flat welded flanges are used for general media. Flat welding flange with neck is suitable for flammable, explosive, corrosive and toxic places. The sealing surface of flat welding flange can be convex surface, concave convex surface and tongue and groove surface. They are different in structure, sealing effect and strength. Flat welding flange is generally called flat plate, also known as lap welding flange. The connection between the flat welding flange and the pipe is to insert the pipe into the flange inner hole to the appropriate position before the lap welding. The characteristics of flat welding flange: flat welding flange not only saves space, reduces weight, but also ensures no leakage at the joint and good sealing performance. The reason for the reduced size of the compact flange is the reduced diameter of the seal, which will reduce the cross section of the sealing surface. The advantages of flat welding flanges are as follows:

Applicable scope and purpose of welding flange