Pneumatic Piston Seals
Low-friction piston rings and seals for pneumatic actuators and automation cylinders
Overview
Piston Seal Types
COP Piston Seals
Standard profile piston seal with a square or rectangular cross-section. Reliable, low-cost and widely used in ISO 15552 cylinders.
Best for: General automation, standard ISO 15552 actuators
Z5 / Z8 / ZT Piston Seals
Optimized profiles with varying lip geometry for balanced sealing force and low friction across different speeds and pressures.
Best for: High-speed automation, pick-and-place, precision motion
E4 Y-Profile Piston Seals
Y-shaped piston seal providing higher sealing force and improved stability in dynamic applications.
Best for: Applications requiring positive sealing and low leakage
PZ / PPD Compact Piston Seals
Compact profiles for small-bore cylinders and space-constrained piston designs.
Best for: ISO 6432 cylinders, compact valves, mini actuators
Custom Piston Seals
Manufactured from drawing or sample with custom OD, width, profile and material.
Best for: Proprietary cylinders, legacy equipment, prototypes
Materials
| Material | Properties | Best For |
|---|---|---|
| NBR | -40°C to +120°C; low compression set; good resilience; low friction; economical | Standard pneumatic service, ISO 15552 cylinders |
| TPU | -35°C to +80°C; excellent abrasion and tear resistance; long life in high-cycle applications | High-cycle automation, rodless cylinders, abrasive conditions |
| FKM | -20°C to +200°C; resistant to heat, synthetic lubricants and chemical vapors | High-temperature or chemically exposed pneumatics |
Sizing
Pneumatic piston seals are sized by the cylinder bore diameter and the piston groove dimensions. Each profile has a specific groove width and depth. Provide the bore diameter, groove dimensions and profile name, or send a drawing.
Standard Pneumatic Piston Seals
- • Bore diameters: 8–320 mm
- • Profiles: COP, Z5, Z8, ZT, E4, PZ, PPD
- • NBR and TPU standard stock
Custom Piston Seals
- • Manufactured from drawing or sample
- • Special profiles and materials
- • MOQ from 1 piece
Frequently Asked Questions
What is the most common pneumatic piston seal profile?
COP is one of the most common profiles for standard ISO 15552 pneumatic cylinders. It is simple, reliable and available in a wide range of bore sizes.
Why does my pneumatic piston seal leak?
Leakage can be caused by worn or damaged seal material, incorrect profile for the groove, oversized bore clearance, contaminated air, or a piston seal installed backwards. Check groove dimensions and air quality first.
Can I use a hydraulic piston seal in a pneumatic cylinder?
Usually not. Hydraulic seals are designed for higher pressure and often have too much friction for pneumatic service. Pneumatic piston seals are optimized for low breakout force and high cycle rates in air.
What is the difference between COP and Z8 piston seals?
COP is a straightforward square-section seal with reliable general-purpose performance. Z8 has a more complex profile tuned for lower friction and better dynamic response in high-speed actuators.
Do piston seals need lubrication?
Many modern pneumatic piston seals are designed to run on dry or minimally lubricated air. However, a small amount of compatible lubricant extends seal life and reduces friction, especially in high-cycle systems.
Can you supply piston seals for my specific cylinder brand?
Yes. We cross-reference piston seal profiles for SMC, Festo, AirTAC, Parker and many other brands. Send the cylinder model or a sample seal for identification.