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Piston Seals

Piston seals are used in hydraulic cylinder systems.  Machined grooves in the cylinder piston allow the piston ring to seal directly against the cylinder bore.  A wide range of groove configurations and sealing profiles allow Gallagher engineers to match your hydraulic sealing application with the optimal sealing system.

Gallagher offers the highest performing urethane materials for your hydraulic application.  New advances in hydrolysis resistant urethanes assist in solving one of the most common hydraulic sealing application problems.

Hydraulic fluid leakage continues to be an important regulatory issue.  Advances in more environmentally friendly hydraulic fluid is causing some material compatibility issues with traditional cylinder seals.  Ensure that the seals in any hydraulic system are optimized for the hydraulic fluids of the future.


This is a high performance general purpose seal suitable for rod and piston use. Engineered to effect a good seal in most light-duty industrial cylinder applications. The sealing lips are accurately machine trimmed to ensure good low pressure sealing while the material resists extrusion at high pressures.

This double-acting seal is a combination of a PTFE slipper seal and an energizing O-Ring. It is produced with an interference fit which, together with the squeeze of the O-Ring, ensures a good sealing effect even at low pressure. At higher system pressures, the O-Ring is energized by the fluid, pushing the PTFE seal against the sealing face with increased force.

This seal is a double-acting sealing element which is energized by an elastomer O-Ring. It can be fitted in existing O-Ring grooves (US standard AS 568 A, MIL-P-5514) and it demonstrates good friction properties, stick-slip-free starting and excellent dry-running. The compact design provides an ideal sealing solution where housing space is limited. This seal should be utilized in light and medium-duty industrial hydraulics.

The GFS-P04 Piston Seal is a high-performance, double-acting O-Ring energized piston seal for demanding dynamic applications. It provides low friction with no stick-slip, minimal break out force and high wear resistance. Does well in performance-critical applications in construction equipment, machine tools, material handling, agricultural equipment, and other industries.

The GFS-P05 Piston Seal provides optimum leakage control and good resistance to extrusion. The seal is a double-acting O-Ring energized piston seal for dynamic applications. Installed in grooves to ISO 7425, it has excellent friction characteristics with no stick-slip, minimal break-out force and high wear resistance.

The GFS-P06 Seal is a single-acting O-Ring energized piston seal for dynamic applications installed in closed grooves. It offers high sealing efficiency, low friction with no stick-slip, which makes it ideal for high-speed applications, and also has minimal break out force and high wear resistance. 

The GFS-P07 Piston Seal is a double-acting piston seal utilizing PTFE paired with an elastomer energizer and x-ring for optimum performance and durability. The PTFE seal ring and the x-ring together provides the dynamic sealing function, while the elastomeric energizer provides the static sealing. 

A double-acting O-Ring energized piston seal in injection molded polyurethane for dynamic applications. The GFS-P08 Piston Seal offers high sealing efficiency, and is tear and abrasion resistant.

The GFS-P09 Piston Seal is a single-acting seal energized by a special slant coil spring. The advantage of this seal lies in its low friction and relatively constant preloading force over a relatively large deformation range. The seal should be used wherever friction has to be kept within a narrow tolerance zone.