Also known as piston cups or cup buckets, can be made for use in water, steam, oil, in other chemical applications. Cup seals are pressure-energized seals although their thin section and good flexibility enable them to be fitted with a high degree of preload to maintain sealing at very low pressures. They are single acting, or unidirectional seals. Sealing in both directions can be achieved by mounting two seals in a back-to-back configuration
Material:
Cup seals have superb uni-directional sealing properties
with low friction. But this requires proper support for accurate functioning and stability of the section. Cup seals are made of either homogeneous synthetic rubber, with fabric lamination or with 'semi-reinforcement' depending on the application.