FFKM is a kind of perfluoroether rubber, which refers to the terpolymer of perfluoroethylene, tetrafluoroethylene and perfluoroethylene. Also known as perfluoro rubber. The long-term effect of perfluoroether rubber sealing parts can improve production efficiency and reduce maintenance costs.

O-ring seal is a kind of rubber seal with circular cross-section. Because its cross-section is O-shaped, it is called O-ring rubber seal, also known as O-ring. It began to appear in the mid-19th century, when it was used as a sealing element for steam engine cylinders. Because the price is cheap, the manufacture is simple, the function is reliable, and the installation requirement is simple, O-ring is the most common mechanical design for sealing. The O-ring bears the pressure of tens of megapascal (thousand pounds). O-rings can be used in both static and dynamic applications where there is relative motion between components, such as the shaft of a rotary pump and the piston of a hydraulic cylinder