Pressure Seal Gate Valve Forged Steel Butt Welding

The working principle of Pressure Seal Gate Valve Forged Steel is mainly to use the sealing principle of wedge sealing surface under pressure, so the greater the pressure, the better the sealing effect. Of course, the pressure should be within the bearing range of the seal. Although the sealing principle is roughly similar, the sealing structure and sealing element materials have different changes to adapt to different working conditions and different preload requirements (the preload is usually applied through the bolt structure and can be adjusted).

Self sealing structure is widely used in the upper sealing of Pressure Seal Gate Valve Forged Steel, mainly in the working conditions above 900LB

Before the pressure rise of the self tightening seal of the valve, tighten the bolts to raise the bonnet, so that the initial sealing condition - the pre tightening specific pressure on the sealing surface - is formed between the bonnet and the wedge gasket, as well as between the valve body and the wedge gasket. When the medium pressure rises, the sealing specific pressure between the bonnet and wedge gasket and between the valve body and wedge gasket increases gradually with the increase of pressure. In the self tightening seal, the working seal specific pressure on the sealing surface is composed of two parts: one is the specific pressure with the tight seal, and the other is the specific pressure formed by the medium pressure. It should be emphasized that the medium pressure in the self tightening seal always tends to increase the specific pressure of the pre tightening seal and increase the sealing performance. The higher the medium pressure, the greater the specific pressure of working seal and the better the sealing performance. According to this feature, as a high pressure sealing technology, self tightening sealing is commonly used for high temperature and high pressure large diameter valves.

Self tightening seal can be divided into axial self tightening seal and radial self tightening seal according to the direction of the force exerted by the medium pressure on the gasket.

Axial self tightening seals include wedge gasket combination seal (Wood seal) wedge seal, flat gasket self tightening seal, C-ring seal and O-ring seal.
Radial self tightening seal:; Double cone seal, B-ring seal, triangular gasket seal, octagonal gasket (oval gasket) seal and lens gasket seal.