What is a spring energised seal?
A spring-energized seal is a high-precision sealing element consisting of a sealing ring made of a high-performance polymer, PTFE, and a high-performance sealing ring with an embedded metal energy storage spring (such as stainless steel).
The metal spring provides elasticity and support to compensate for the wear of the sealing material. The design structure of the spring includes U-shaped, V-shaped, O-shaped, etc.
The U-cup sealing ring is made of PTFE, filled PTFE material, ultra-high molecular weight polyethylene, polyimide, polyetheretherketone (PEEK), etc., or other high-functional polymer materials through precision turning. Depending on the material, it can meet the temperature range of -190-340°C and hardly react with any chemical reagents.
Different spring forms can be selected according to different working conditions. Stainless steel materials generally include SUS301, SUS304, SUS316, and SUS718. The spring load can meet the extremely demanding low-friction requirements in dynamic applications, including the high load requirements usually required for low-temperature sealing.
The spring provides permanent elasticity to the U-cup sealing ring, compensating for material wear and offset and eccentricity of mating parts. System pressure will also cause the U sealing ring to seal well, under high or low pressure, through spring elasticity and system pressure.
The spring-energized seal is a sealing form developed in recent years. Like the combined seals, such as the Glyd ring piston seal and Step seal, it fully utilizes the superior performance of each component material so that the performance far exceeds any single material seal.
The design of the spring energised seals enables them to achieve stable sealing in harsh environments, such as high pressure, high temperature, and chemical corrosion. Installed in the sealing groove, the spring is compressed, causing the lip of the U sealing ring to fit closely to the sealing groove, thereby forming a seal.
Working principle
The elastic effect of the metal spring keeps the sealing material close to the sealing surface at all times, and the PTFE material fills the sealing gap to prevent leakage. It is suitable for both static seals and dynamic seals, especially in high-pressure and high-temperature environments.
The PTFE sealing ring contacts the two surfaces to be sealed and acts as a seal, so it requires a low friction coefficient, high strength, wear resistance, resistance to working media, and resistance to high or low temperature in the working environment.
The embedded stainless steel spring provides pressure for the PTFE sealing ring so that the sealing lip is always tightly pressed against the sealing contact surface to prevent leakage, especially when the internal pressure is low, zero pressure, or even negative pressure. The spring is the only source of sealing pressure.
The requirements for the spring are relatively simple: resistance to high and low temperatures, corrosion resistance, and relatively constant elastic force. Although these requirements are not many, they are not easy to achieve, and the requirements for the material, process, and shape of the spring are high.
Features
1. It can be used for reciprocating motion, rotation (swing), and static sealing;
2. It can be used for almost all fluids and chemical media.
3. It has excellent sealing performance for high and low pressure and vacuum sealing.
4. It has low friction, small starting resistance, stable movement, and no creeping phenomenon.
5. It has a long service life and can be used for oil-free lubrication sealing.
6. A variety of materials are available to adapt to rapid temperature changes and various complex working conditions;
