Piston Seals

In pneumatic cylinders, cushioning seals are part of a design that provides for controlled final position retardation. Up on approaching the final position, a tapered sleeve, firmly located on the piston rod, progressively closes off the open passage toward the line connection of the cylinder. In this phase of motion, the defluent medium is led via a, usually adjustable, needle valve, the adjustment of which controls the degree of stroke movement retardation. During reverse operation, the cushioning seal designs provide a non-return valve functionality and ensure free flow. Parker offers robust seal profiles, suitable for the harshest operating conditions and showing extreme wear and high-temperature resistance.

Buffer seals are primary seals in tandem sealing configurations. Designed to withstand pressure peaks from the system, Parker hydraulic buffer seals employ an unsymmetrical cross-section design and are often combined with anti-extrusion rings to prevent gap extrusion. State-of-the-art designs include a pressure-relief functionality from the low pressure side, addressing concerns related to drag-oil pressure trapped between the tandem elements. Our comprehensive selection of premium buffer seals are designed for use with hydraulic cylinders, providing excellent wear resistance, and high pressure capabilities. Parker buffer seals combine advanced polymer materials, such as PTFE or TPU with sophisticated product design.