The PTFE gasket applies a pressing force to the Teflon gasket when the valve flange bolt is tightened, the pre-tightened gasket is compressed, and the uneven micro-gap on the sealing surface is filled, thus preventing the medium from leaking. Initial sealing conditions are formed, and a pre-tightening specific pressure is formed on the sealing surface.

When the pressure of the medium rises and the valve is operated, the pre-tightening pressure on the sealing surface decreases, and the PTFE gasket rebounds. If the PTFE gasket has sufficient resilience so that the working seal specific pressure on the sealing surface is always greater than the medium and the operating specific pressure, the sealing surface maintains a good sealing state. It can be seen that the necessary condition for forced sealing is that under the action of the medium and the operating force, the sealing surface can still maintain a certain pressing force.

Dongguan Teflon retaining ring manufacturers stressed that: in forced sealing, the medium pressure always tends to reduce the pre-tightening seal to reduce the sealing performance. Typical structures for forced sealing of PTFE gaskets are flat gasket seals, wound gasket seals and toothed gasket seals, etc., which are commonly used for low pressure, medium pressure and medium and small diameter valves.