China Manufacturer Piston Rubber Product

Bonding the piston to the metal hub provides the strongest, most extrusion-resistant style of piston available and also minimizes any leak paths from forming on the inner diameter of the piston. The bonded-lip design has an open inner sealing lip that also enables the rubber to expand inward as a result of thermal expansion without excess loading of the sealing lip.
With proper cooling and lubrication from the liner-wash system, the bonded-nitrile piston can be used successfully at temperatures up to 250°F (121°C).