Common things for flat welding flanges. The fixing form of the flange and the pipe is applicable to: the flange is sleeved at one end of the pipe, the inner and outer ports of the welding flange, the fixed flange, and the nominal pressure is 2 Below 5MPa.
Butt welding flange, also known as high neck flange and large tail flange, has high strength, not easy to deform and good sealing performance. It has various sealing surfaces and is applicable to a wide range of pressures.
Butt welding flange nominal pressure is 2 Below 5MPa, the specification range is dn10~ 800mm.
The concave convex sealing surface faces the welding flange. Since the concave convex sealing surface has high tightness and is under great pressure, one side of the sealing surface of each flange must be concave and the other side convex. Please make no mistake. The nominal pressure range is 4.0 ~ 16 0mpa, the specification range is dn15~ 400mm.
Tongue and groove sealing surface welding flange the flange has good sealing performance, and the structure is similar to the concave convex sealing surface flange. One flange needs two combinations. The nominal pressure range is 1.6~6 4MPa, the specification range is dn15~400mm.
Trapezoidal groove sealing surface welding flange this flange is commonly used in petroleum industry piping and is under great pressure. Nominal pressure is 6.4 ~ 16 0mpa, standard range: dn15~ 250mm
The above sealing butt welding flanges differ only in the shape of their sealing surfaces. From the point of view of installation, the connection method for butt welding flanges of any shape is the same, and the manpower, materials and machine shifts used are basically the same.
The sleeve movable flange is also called the roll end locking flange. The flange is not directly welded with the pipe, but uses the pipe sleeve as the sealing contact surface to fasten the embedded flange. It is mostly used for copper, lead and other non-ferrous metals and stainless steel pipes. The greater advantage is that the flange can work freely, so it is very convenient for the flange to pass through the bolt and can not bear large pressure. For nominal pressure 0 For piping connection below 6Mpa, the specification range is dn10~500mm.
Welding ring movable flange is also called welding ring loose flange. It is a product that the welding ring with the same material as the gas pipe is directly welded at the end of the gas pipe, and the welding ring is used as the sealing surface. The sealing surface has two types: smooth and tenon groove.
Welding ring flange is mainly used for connecting stainless steel pipe with thick pipe wall and steel pipe flange. The flange is made of Q235 and q255 carbon steel, and the nominal pressure and specification range are pn0 25 MPa is dn10~450mm; PN1.0MPa is dn10~300mm; PN1.6MPa is dn10~200mm threaded flange. There are two kinds of flanges connected with the pipe end by screws: high pressure and low pressure.
Low pressure threaded flange is made of steel and cast iron. With the development of industry, low pressure threaded flange is replaced by flat welding flange, which is rarely used except in special cases.
The sealing surface of high-pressure threaded flange is formed by the pipe end and lens gasket. The processing precision of the contact surface between the thread and the pipe end gasket is high, and the applicable pressure is pn22.0 and pn32 0mpa, the specification range is dn6~ 150mm.
