The Hallite 511 is a loaded U cup utilising a polyurethane or polyester shell energised by a high specification resilient O ring. At zero or low pressure, the O ring helps to increase the sealing force preventing any bypass. As pressure rises the sealing force increases and the O ring ensures complete lip actuation under most conditions. The symmetry of the seal allows it to be used on both rod and piston applications and its flexibility enables easy installation. Ideally suited for single acting applications, the Hallite 511 can also be fitted back to back for use in double acting applications. Maximum pressure of 5000 psi operating temperature range -30 Degree C to +120 Degree C.