The Hallite 714 is a double acting seal capable of passing over ports. The reinforced, heat stabilised, thermoplastic sealing face, expands and contracts to fill the gap between the piston and the cylinder wall and has a step-cut joint for ease of installation. It will tolerate a considerable extrusion gap, thus reducing the possibility of piston-to-bore contact, and it offers excellent static load holding capability. The special profile nitrile rubber energiser responds quickly to pressure changes, providing excellent sealing characteristics under all pressure conditions