Pressure relief valve

摘要

The valve has a spring loaded piston with an axial bore (19) an has a radial outlet (22). The outlet has a closed position on one side of a seal ring (9) arranged in the cylinder wall that encloses the piston. The outlet has an open position on the other side of the seal ring. The outlet opens into an annular space which connects further outlets (26). The piston is stepped and has a reduced diameter on the other side of the annular space and is sealed by a further seal. This seal is biassed by a spring which acts against the smaller surface of the piston.