Spring energy-storage seal ring is the abbreviation of spring variseal (spring composite seal), which is also the plug seal,

"Fansai" itself is a transliteration of "compound seal", so it is not necessary to add the word "seal" after "Fansai". If it is called by custom, it is OK to add the word "seal". Of course, it is better to directly say "spring energy storage seal" in Chinese.

It is a U-shaped Teflon seal with special spring inside. With proper spring force and system fluid pressure, the sealing lip surface is pushed out and the metal surface of the seal is pressed gently to produce excellent sealing effect. Various special springs are used to overcome the elastic problems of Teflon or other high-performance rubber and plastic, and to develop and replace the vast majority of seals used in static or dynamic, reciprocating or rotary motion, The operating temperature range can be from cold coal to 300 ℃, the pressure can be from vacuum to ultra-high pressure of 1400kg/cm, and the moving speed can be as high as 20m/s。

The structure of the plug seal is shown in the figure below, which is divided into two parts: the external part is made of special engineering plastics, and the internal part is made of stainless steel springs made of special materials.

The materials of plastic and stainless steel are different due to different working conditions and working media. Generally, plastic materials include: pure tetrafluoroethylene, filled tetrafluoroethylene, ultra-high molecular weight polyethylene, polyimide, polyetheretherketone, etc. Stainless steel materials generally include SUS301, SUS304, SUS316 and Inconel ® 718, Elgiloy、Hastelloy ® C276, etc

The spring type can also be H (O) type V type C type F type according to different working conditions

Spring type	Spring characteristics	Application characteristics
	The V-shaped cantilever spring can make the PTFE sealing lip at the long arm end (pressed) on the sealing surface to provide a medium sealing force, provide a broader spring load and a larger supplementary spring force, with stable elasticity and small deformation, and can be directly installed in the standard O-ring groove. If necessary, a back carrier ring can be added.	1. Reciprocating shaft and piston seals 2. During static sealing, the sealing groove can allow large tolerance and poor alignment, 3. The operating temperature of dynamic seal can reach 260 ° C, and the speed of rotary shaft seal can reach 4m/s
	The H-type spring has a high coefficient, which is suitable for medium and high pressure load applications. It provides a large spring load within a small compression range, and the force on each coil of spring is uniform.	1. Shaft and piston seal under static state, medium and high pressure seal 2. For fast dynamic sealing, the speed is lower than 3M/S 3. Internal and external pressure end seal
	C-type spring is a helical spring with oblique section, which has large deformation and large compensation capacity for dimensional deviation	1. Suitable for conditions with high friction requirements and low pressure environment

The external plastic sleeve contacts with the two surfaces to be sealed, so it requires low friction coefficient, high strength, wear resistance, working medium resistance, high or low temperature in the working environment,

The internal stainless steel spring provides pressure for the external seal sleeve, making the seal sleeve tightly pressed on 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 springs are relatively simple: high and low temperature resistance, corrosion resistance, and relatively constant elastic force. Although these requirements are not many, they are not easy to achieve. The requirements for spring material, technology and shape are high.