Pressure vessel flange

The pressure vessel is widely used in petrochemical industry and is one of the main production tools of petrochemical industry. Due to process requirements and equipment installation and maintenance, pressure vessels often need to set up container flanges (such as common tube shell heat exchangers, reaction kettle, tower, filter, etc.).

Pressure vessel flange is divided into flange ring, flange, flanged flanges and arbitrary flanges. Our country commonly used pressure vessel standard JB/T4701-4703 flange has three types: a (flat welding flange, long hepatitis b flat welding flange and butt welding neck flange, including influenza a, b flat welding flange belong to any type of flange. Flange and gasket, collectively known as the flange joint, flange joint is extremely common, involve very widely used in engineering design of a kind of parts and components, is prone to the problems in the process of engineering design and use of key parts. Flange joint design is one of the important contents in pressure vessel design. In selecting standard of flange and a calculation of non-standard flange, a (designers choose material unreasonable phenomenon is more serious, the hepatitis b flat welding flange even long neck butt flange instead of a (flat welding flange is also more, cause unnecessary waste. Therefore, it is necessary to discuss the selection and calculation of common a-level welding flange.

Pressure vessel flange is divided into flat welding flange and butt welding flange. The flat welding flange is divided into two types: a, flange and b.

1. Flat welding flange

1) the type b flange has a short cylinder, so the rigidity is better than the one flange, which can be used for high pressure and larger diameter occasions.

2) weld form: type a is v-type groove, type b is u-shaped groove, so the type b is more easily welded, so its strength and rigidity are higher.

2. Butt welding flange

Because of long neck, and use of butt welding, it is better to be rigid and suitable for higher pressure occasions.

Pressure vessel flange standard:

Pressure vessel a level welding flange standard: JB/t4701-2000

Standard for flanging flange of pressure vessel: JB/t4702-2000

Pressure vessel long neck butt welding flange standard: JB/t4703-2000

Outer cover side flange standard: JB/t4721-92

The standard of the flanged flanges is usually the selected hg20592-hg20535-2009

What are the sealed forms of pressure vessel flange?

There are three main forms.

(1) forced seal. Tighten the sealing surface by forcing the sealing of the cover and the connecting bolt of the cylinder flange to achieve the sealing purpose, such as the sealing of the flat cushion and the sealing of the carzari.

(2) self-sealing. Using the pressure of the medium in the container, the sealing surface can be pressed tightly to achieve the sealing purpose. Its sealing force increases as the pressure of the medium increases. And under high pressure can maintain a reliable sealing performance, such as combined seal, o-ring seals, C ring seal and seal B ring seal, wedge, octagon gasket and elliptical gasket seal, flat pad since the tight seal and seal wood, nitrogen seal, etc.

(3) semi-self sealing. Use the pressure of the medium in the container, and then use the fastener's connection to make the sealing surface pressure to achieve the sealing purpose, such as double cone seal.