Lip seal, also known as spring energized ring, is widely used in various fields because of its excellent sealing performance.

In the production of valves under special working conditions, rubber O-rings cannot meet the requirements, so other sealing schemes shall be selected instead.

The advantage of lip seal is that it can realize "self sealing" like an O-ring, that is, its sealing performance increases with the increase of pressure. In addition, it can reduce friction, have a long service life, and can be applied to more harsh environments.

Sealing principle of lip seal

The high-pressure medium escapes under the action of pressure, and the escaping gas or liquid spreads along the gap between the parts. After reaching the lip seal position, due to the preload of the lip seal energy storage spring, the sealing lip is pressed against the outer wall of the part, so that the medium with slightly lower pressure cannot pass through the barrier. With the gradual increase of the escaping medium, the pressure in the lip seal ring groove gradually rises, At this time, under the pressure of the lip seal, the sealing lip will better fit on the inner and outer walls of the parts. Finally, the pressure and the pressure in the container cavity will reach a balance, and the lip seal will realize the sealing.

Lip seal is a pressure auxiliary sealing device with polytetrafluoroethylene (or other polymeric materials) jacket, which is specially equipped with a corrosion-resistant metal energy storage spring.

The main types of springs used for ball valves are:

Optional materials and application scope

Common materials:

1. Common materials of sealing jacket:

Pure PTFE / modified PTFE / Polymer Filled PTFE / HDPE / ETPE / PEEK, etc

2. Common materials of energy storage spring:

304 SS / 316 SS/ Inconel / Elgiloy / 17-7ph / 301 SS/ 302 SS / Hastelloy nickel base alloy, etc

Application in valves

• Low temperature or high temperature top mounted ball valve
• Three piece fixed ball valve at - 100 ℃
• Low temperature butterfly valve at - 196 ℃
• API 6A gate valve with pressure of 5000PSI