Parker Urethane Rings

Parker Urethane O-Rings

568 Cross Section

Parker urethane o-rings offer the material advantages exclusive to the Resilon family of compounds in standard and custom o-ring sizes. High temperature Resilon o-rings eliminate the need for back-ups, simplifying installation and reducing damage due to spiral failure.

568 Profile, Resilon® O-Ring

Technical Data

Standard Materials* Temperature Pressure
P4300A90 -65°F to +275°F (-54°C to +135°C) 5,000 psi (344 bar) dynamic 10,000 psi (688 bar) static
P4301A90 -35°F to +225°F (-37°C to +107°C) 5,000 psi (344 bar) dynamic 10,000 psi (688 bar) static

Alternate Materials: For applications that may require an alternate material, please consult ESP.


Parker Urethane D-Rings

DG Cross Section

Parker’s Resilon polyurethane D-ring is a one-piece hydraulic valve sealing solution which delivers longer life and reduced warranty costs over traditional multiple-component seals.The molded “D” shape which is higher in the middle and lower on the ends, provides sealing in critical areas while reducing the chance of a seal being cut during installation. Its sealing lip contact footprint is minimized, thus reducing the amount of friction between seal and bore while providing expected sealing performance. The “D” shape is symmetrical so there is no performance degradation as the valve cycles in the reverse direction nor concern of backward installation of the seal. The design also incorporates “pressure pedestals” to eliminate the potential for “blow-by,” common in reverse cycling.

DG Profile, Urethane D-Ring

Technical Data

Standard Materials* Temperature Pressure
P4300A90 -65°F to +275°F (-54°C to +135°C) 5,000 psi (344 bar) dynamic 10,000 psi (688 bar) static
P4301A90 -35°F to +225°F (-37°C to +107°C) 5,000 psi (344 bar) dynamic 10,000 psi (688 bar) static

Alternate Materials: For applications that may require an alternate material, please consult ESP.


Parker Urethane Head Seals

HS Cross Section

HS profile static head seals are ideal for replacing o-rings and backups in hydraulic cylinder heads. Installation is simplified and failure due to pinching and blow-out is eliminated. The characteristics offered by P4700 urethane provide the performance advantages for this profile. As mobile equipment OEM’s continue to consider warranty costs, one area of focus has been a review of down time related to cylinder head glands. Two of the most common seal failures on cylinder heads are o-ring back-up blow-out and pinched back-ups. Both failures are common in systems with high eccentricities or large extrusion gaps. To address these situations and to reduce down time HS profile static head seals are specified to replace the industry-standard o-ring and backup. Incorporating high performance plastics with a stable, symmetrical geometry dramatically reduces the risks of installation damage and back-up blow-out. Both problems are eliminated with the HS profile’s one piece urethane design offering improved fit and a stable geometry.

HS Profile, Static Head Seal

Technical Data

Standard Materials* Temperature Pressure
P4700A90 -65°F to +200°F (-54°C to +93°C) 10,000 psi (688 bar) static

Alternate Materials: For applications that may require an alternate material, please consult ESP.


ESP – Parker “Seal Technology Center”
Parker Distributor Seal Technology Center

ESP International is proud to be one of the few premier distributors to qualify as a “Parker Seal Technology Center (STC)”.

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