Hydraulic Buffer Seals

Hydraulic Buffer Seals are designed to protect primary piston rod seals from sudden pressure peaks and pressure fluctuations in hydraulic cylinders. Installed on the high-pressure side of the rod sealing system, they help reduce the load on the main rod seal and improve sealing reliability in demanding hydraulic applications.

These seals are widely used in construction machinery, agricultural equipment, hydraulic presses, lifting equipment and other heavy-duty hydraulic systems where frequent pressure changes and shock loads occur.

Features & Advantages

Hydraulic buffer seals are typically designed to absorb pressure spikes while maintaining controlled fluid movement within the rod sealing system.

Key features include:

• Pressure Peak Protection: Helps reduce sudden pressure loads acting on the primary rod seal.

• High-Pressure Capability: Selected designs are suitable for hydraulic systems operating at pressures of 400 bar or higher.

• Anti-Extrusion Performance: Backup rings help prevent seal extrusion under high pressure and demanding operating conditions.

• Improved Rod Seal Protection: Reduces the risk of damage and premature wear caused by pressure fluctuations.

• Wear Resistance: Polyurethane and engineered PTFE materials provide good wear resistance in suitable hydraulic applications.

• Pressure Relief Design: Selected profiles allow trapped pressure between the buffer seal and primary rod seal to return toward the hydraulic system.

Materials & Seal Construction

Hydraulic buffer seals are commonly manufactured using polyurethane (PU/TPU), PTFE and engineered thermoplastic materials.

PU buffer seals provide good abrasion resistance, flexibility and resistance to extrusion. They are often combined with POM or polyamide backup rings to improve performance under high pressure.

PTFE buffer seals typically use a filled PTFE sliding ring with an elastomeric energizer, often made from NBR. These designs offer low friction and are suitable for selected medium- and heavy-duty hydraulic applications.

Seal profiles may include U-cup designs, stepped sealing rings and multi-component constructions. The appropriate design depends on pressure conditions, rod speed, operating temperature and installation groove dimensions.

Typical Applications

Hydraulic buffer seals are commonly used in:

• Excavators and construction machinery

• Agricultural and earthmoving equipment

• Hydraulic cylinders and actuators

• Forklifts and material handling equipment

• Hydraulic presses and injection molding machines

• Cranes and lifting equipment

• Mining and heavy-duty industrial machinery

Standard & Custom Supply

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

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

For quotations, please provide the piston rod diameter, housing dimensions, seal profile, material and required quantity. Information about working pressure, peak pressure, operating temperature, rod speed and hydraulic fluid is also recommended to help confirm a suitable sealing solution.