Flanges are also called flanges or flanges. Parts that connect pipes and fittings to each other. Connect to the end of the pipe. There are holes on the flange, bolts can be used to make the two flanges tightly connected. By pre-tightening the bolts, the gasket between the sealing surface of the flange is compressed and solidified, and the uneven gap on the sealing surface of the flange is filled, preventing the permeability of the medium from leaking through the inner capillary of the gasket and the gasket and The interface between the sealing surfaces is leaking. So as to achieve pre-sealing.

According to the degree of integrity of flange and equipment or pipeline connection:

Flat welding flange: used for occasions where the temperature and pressure are not too high. Flat welding flanges include PL flanges and SO flanges.

PL flanges are suitable for the connection of steel pipes with a nominal pressure not exceeding 2.5MPa. The sealing surface of PL flanges can be made into smooth, concave and convex and tongue and groove types. Smooth PL flanges are the most widely used .Mostly used when the medium conditions are relatively mild, such as low-pressure non-purified compressed air and low-pressure circulating water.

The SO flanges with necks is low, which improves the rigidity and carrying capacity of the flanges. Compared with butt welding flanges, the welding workload is large, the welding rod consumption is high, and it cannot withstand high temperature and pressure, repeated bending and temperature fluctuations, but it is more convenient for on-site installation and can omit the process of welding seam scratching, which is more popular.

Butt welding flange: suitable for important occasions with high pressure and temperature, toxic, flammable, and explosive. The cost is high. WN flanges are commonly referred to as "high-hub" flanges. The purpose is to transfer the pressure of the pipeline, thereby reducing the high stress concentration in the flange base. WN flange  is the best design for butt welding those flanges that are provided due to their inherent structural value. However, the price is relatively high because the production process of the product is complicated.

The difference between flat welding flange and butt welding flange:
1. Different forms of welds: The welds of flat welding cannot be radiographically inspected, but the welds of butt welding can be; flat welding is two fillet welds and butt welding is one butt girth weld.
2. The nominal pressure is different: the nominal pressure of the necked flat welded flange is: 0.6---4.0MPa, while the nominal pressure of the necked butt welded flange is: 1--25MPa, obviously, the necked flat welded flange The adaptation pressure level is lower.
3. Different connection methods: generally flat welding flanges can only be connected to pipelines, but not directly connected to butt welding pipe fittings; butt welding flanges can generally be connected to all butt welding pipe fittings (including elbows, tees, reducers, etc.) Etc.) Direct connection, including pipes of course.

The reducing flange is anti-corrosion, acid and alkali resistance, long service life, etc., reasonable price calculation, smooth surface, acid and alkali resistance, high temperature resistance, beautiful appearance, strong texture performance, professional integral forging, high-precision CNC lathe turning, ordinary lathe precision Cars, argon arc welding and other processing are widely used in water conservancy, electric power, power stations, pipe fittings, industry, pressure vessels, etc.

Stainless steel flanges are widely used in boiler and pressure vessel, petroleum, chemical, shipbuilding, pharmaceutical, metallurgical, machinery, food and other industries.