Parker 426337505250-625 Polypak Seal 5.25x6 in

Product Description

The PARKER 426337505250-625 is a Polypak-style hydraulic rod and piston seal designed for use in fluid power systems where reliable dynamic sealing is required. With a 5.25-inch inner diameter, 6-inch outer diameter, and 0.375-inch thickness, this seal provides a positive lip contact that compensates for wear over time, maintaining consistent sealing performance. Rated for an operating temperature range of -20 degrees F to 250 degrees F and a maximum operating pressure of 850 psi, it suits demanding hydraulic cylinder and actuator applications. Installation is performed by hydraulic system technicians and industrial maintenance professionals.

This Polypak seal is suited for hydraulic cylinder rod and piston gland applications in industrial, mobile, and fluid power equipment. The single-acting lip seal design is commonly used in medium- to heavy-duty hydraulic systems where dynamic reciprocating motion is present. The 5/8 pipe thread connection reference makes it compatible with standard ported gland fittings. It is packaged individually and sold in single-unit quantities, making it appropriate for targeted maintenance and repair tasks where only one seal size is required at a time.

Key Features

• Polypak lip seal geometry compensates for wear, maintaining sealing contact throughout service life
• 5.25 inches ID x 6 inches OD x 0.375 inches thick for precise gland fit
• Rated to 850 psi maximum operating pressure for medium- to heavy-duty hydraulic service
• Operating temperature range of -20 degrees F to 250 degrees F covers most industrial hydraulic fluid environments
• 5/8 pipe thread reference for standard gland compatibility
• Single-unit packaging supports individual repair and replacement tasks

Compatibility

Designed as an OEM-style replacement Polypak seal for hydraulic cylinders and actuators with a 5.25-inch ID gland bore and 6-inch OD housing dimension in industrial and mobile fluid power applications.

Installation Notes

Installation of hydraulic seals should be performed by qualified hydraulic system technicians. Depressurize and fully isolate the hydraulic circuit before disassembling any cylinder or actuator. Use a seal installation tool or smooth mandrel to avoid cutting or rolling the lip during installation into the gland groove. Inspect the rod and bore surfaces for scoring or contamination before fitting the new seal, as surface damage will shorten seal service life.