Flange threaded connection (screwed) flange and welding flange. Low-pressure flange of small diameter is usually silk, high pressure and low pressure large diameter is commonly used welding flange, joint bolt diameter and thickness of flange plate of different pressure and quantity is different. According to the different levels of pressure, flange gasket also have different materials, from low-voltage asbestos mat, high-pressure asbestos pad and four fluorine pads to metal pads.

The main characteristic of flange connection are replacing the more convenient, very high strength, sealing performance is very good. When install the flange requirements remain parallel two flanges, the flange sealing surface can't touch, but to clean up. Used in the flange gasket, chosen according to the design rules. Flange connection is an important connection mode of pipeline construction. Flange connection use is very convenient, and can withstand more pressure.