The Critical Role of Lip Seals To Enhance Ball Valve Performance

Application of Lip Seal in Ball Valve

Spring-energized seals, or lip seals, are popular in many industries because they provide excellent sealing performance. When special operating valves are considered, traditional rubber O-rings cannot meet the requirements; hence alternative sealing solutions have to be adopted. The self-sealing feature can be one advantage of a lip seal where swelling pressures increase with pressure, just like O-rings. In addition, these seals are very effective in reducing friction that might result in wear and tear under consideration of severe conditions. Lip seals have gained wide acceptance in many applications due to their excellent sealing ability and resistance.

The use of lip seals in ball valves has proven to be very effective in achieving a reliable and efficient means of effecting the seal. These seals are designed to ensure that the closure achieved is tight and does not allow any leaks to pass even under high-pressure conditions. In effecting a seal by the utilization of a lip seal, ball valves are capable of stopping the escape of both fluids and gases; this makes them applicable across an array of industries.  The ability of lip seals to withstand extremely high temperatures and resist chemical corrosion further enhances its applicability in different environments. When used as described, it reduces maintenance costs and extends the life of a valve. This has an overall effect on users as it improves performance, safety, and durability while reducing cost.

Ball Valve sealing principle

The medium under escape is high pressure, which spreads the gas or liquid along the parting between parts up to where the lip seal is located. This preload at the energy storage spring of the lip seal forces the sealing lip against the outer wall of the part so that slightly less pressured medium cannot pass. The pressure within a ring gradually increases with growing values of surrounding media; consequently, it provides support against walls when acting from pressures applied by them too. The final result occurs when these two forces (container cavity) attain equilibrium under action from all directions.

Lip seal is an auxiliary pressure sealing device with the use of a special PTFE (or other polymeric materials) jacket, and corrosion-resistant energized metal spring. This advanced design makes the lip seal ideal for high-pressure gas or liquid applications. The PTFE jacket has excellent resistance to most corrosive fluids, which enables it to work in numerous industries. The spring also acts as an energy reservoir that helps industrial ball valve in producing a more positive Sealing action against the outer wall surface contact. In this way, the combination of materials and design ensured long-term reliability in sealing performance by avoiding any possibility of weeping under high pressure or heavy shock loads.

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 Ball 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