Hydraulic Piston Seals

Hydraulic Piston Seals are designed to prevent internal fluid leakage between the piston and cylinder bore in hydraulic cylinders. By maintaining pressure separation across the piston, these seals help hydraulic equipment generate force, control movement and operate efficiently under demanding working conditions.

Available in single-acting and double-acting configurations, hydraulic piston seals are widely used in construction machinery, agricultural equipment, industrial hydraulic systems, lifting equipment and hydraulic presses.

Features & Advantages

• Pressure Retention: Helps prevent hydraulic fluid from bypassing the piston, maintaining cylinder force and efficiency.

• Single & Double-Acting Options: Available for hydraulic systems requiring pressure sealing in one or both directions.

• High-Pressure Capability: Selected sealing profiles are suitable for operating pressures of 400 bar or higher.

• Wear & Extrusion Resistance: Polyurethane and reinforced sealing arrangements provide durability under demanding hydraulic conditions.

• Low-Friction Options: PTFE-based seals help reduce sliding friction and stick-slip during reciprocating movement.

• Multiple Seal Profiles: Available in U-cup, compact, PTFE slide ring and multi-component designs for different cylinder configurations.

Materials & Seal Construction

Hydraulic piston seals are commonly manufactured using polyurethane (PU/TPU), nitrile rubber (NBR), filled PTFE and engineered thermoplastic materials.

PU piston seals provide good abrasion resistance, mechanical strength and sealing performance, making them suitable for general industrial and mobile hydraulic cylinders.

PTFE-based piston seals typically combine a low-friction PTFE sliding ring with an elastomeric energizer. They are commonly selected for applications requiring smooth movement, low friction and precise hydraulic control.

Compact piston seals may use multiple components, including elastomeric sealing elements, anti-extrusion rings and guide elements. These constructions are widely used in heavy-duty hydraulic equipment.

Single & Double-Acting Piston Seals

Single-Acting Piston Seals

Designed to seal hydraulic pressure from one direction. Common designs include polyurethane U-cup seals and selected PTFE-based sealing profiles.

Double-Acting Piston Seals

Designed to maintain pressure separation when hydraulic pressure alternates between both sides of the piston. Common designs include PTFE slide ring seals, compact piston seals and other bidirectional sealing assemblies.

Seal selection depends on the cylinder configuration, pressure direction, operating conditions and installation groove design.

Typical Applications

Hydraulic piston seals are widely used in:

• Excavators and construction machinery

• Agricultural tractors and hydraulic equipment

• Hydraulic presses and industrial cylinders

• Forklifts and material handling equipment

• Cranes and lifting systems

• Mining and earthmoving machinery

• Injection molding and manufacturing equipment

• Hydraulic cylinder repair and maintenance

Standard & Custom Supply

CORA SEALS supplies hydraulic piston seals in various materials, dimensions and profiles for equipment manufacturers, hydraulic repair companies, industrial distributors and aftermarket replacement applications.

Standard metric and inch sizes, as well as custom sealing configurations, can be sourced according to technical drawings, samples or existing part numbers.

For quotations, please provide the cylinder bore diameter, piston groove dimensions, seal profile, material and required quantity. Working pressure, temperature, sliding speed and hydraulic fluid information can also help confirm a suitable sealing solution.