Graco 166771 Packing Piston Cup

The Graco 166771 Packing Piston Cup is a vital part of the air-operated diaphragm pumps. It’s a specialized seal that keeps the fluid from leaking out of the piston and cylinder wall, and keeps the pump running at its better. The packing piston cup is formed from some durable flexible material capable of withstanding high pressure and rough chemicals. The design is to compress and conform to the shape of the cylinder wall, providing a reliable seal. Since the piston is in and out of the cylinder, the packing cup flexes and expands to keep a tight seal preventing leakage of fluid.