Welding neck flanges can be used to connect pipelines to maintain the sealing performance of pipelines. Welding neck flanges are easy to replace pipe sections, easy to disassemble and check the condition of pipes, and easy to seal pipe sections made of carbon steel. Flange is the connection of two large diameter pipes. This device is also called a carbon steel flange, and it 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 hardens, while plasticity reduces strength. Flange connections may need to withstand higher tensile, compressive, torsional and shear strengths. Therefore, Welding neck flange is a better choice.

Precautions for the use of butt welding flanges:

1. In order to prevent intergranular corrosion caused by the heating of the welding flange, the butt current should not be too large, about 20% smaller than that of carbon steel electrodes, the arc should not be too long, the intermediate layer should cool quickly, and the weld should be narrow. The electrode should be kept dry, the calcium-titanium type should be dried at 150°C for 1 hour, and the low-hydrogen type should be dried at 200-250°C for 1 hour (do not repeat drying, otherwise the coating will easily crack and peel off) to prevent the electrode coating from sticking. Attached to oil and other dirt to avoid increasing the carbon content of stainless steel and Welding neck flanges in the weld, which will affect the quality of the weld.

2. During the butt welding process of the welding neck flange, repeated heating will cause carbides to precipitate, thereby reducing corrosion resistance and mechanical properties. After the chromium stainless steel welding flange is hardened, the American standard flange is large and easy to crack. When the same type of chromium stainless steel electrode (G202, G207) is used for butt welding, it should be preheated and cooled slowly for more than 300 times and more than 700 times.