Pneumatic Piston Seals

Pneumatic piston seals stop air passing between the two chambers of the cylinder. A leak here can be neither heard nor seen from outside; it shows up as reduced thrust, longer cycle times and a compressor that starts more often than it should. In terms of energy costs, internal leakage in pneumatic systems is an expense that quietly grows unnoticed.

The most common profile type in this category is the single-acting lip (cup) seal; in double-acting cylinders these are used in pairs, back to back. In some applications the piston seal is designed as a single assembly together with guiding and cushioning functions. Cylinders that need magnetic position sensing also carry magnet holders in the piston assembly.

Materials include NBR, polyurethane (PU), PTFE and POM, with aluminium and sheet-metal components in the carrier and support parts. In pneumatics the deciding criteria are low friction, low breakaway force and stable behaviour over a high number of cycles, rather than pressure resistance.

Across the product tables in this category, operating limits reach up to 16 bar and span −40 °C to +105 °C. The range applies to the whole category; each profile's own value is listed in the table on its product page.

These products are used in push and gripper cylinders on automation lines, packaging and labelling machines, pneumatic presses and robot end effectors. Because of the high cycle counts, failures in pneumatics rarely happen suddenly; they develop as a gradual loss of performance — thrust drops, cycle time lengthens and the line slows down. Tracking these two values regularly is the most practical way to prevent unplanned stoppages.

Selection requires the piston diameter, groove diameter and groove width, whether the cylinder is single- or double-acting, and whether the line is lubricated. We supply and support from our base in OSTİM, Ankara.