Hydraulic cylinders are being used in mechanical applications where reciprocating forces and movements are needed. Sealing element is one of the most important parts of the cylinders. The sealing elements are being installed into the respective groove with a preload. Figure 1 shows the sealing element in free state, preload after the assembly of the seal and the free space needed in the housing.
The sealing element is able to work in low pressures due to this preload. Figure 2 shows the pressurized media filling into the groove and sealing element is expanded with this pressure. Sealing elements are produced from such materials that can change their form when force is applied (Figure 2) and can return to the original form when this force disappears (Figure 1). In this respect sealing elements are produced from elastomers, thermoplastics or thermoplastic elastomers.