Hydraulic & Fluid Seals

Buffer Seals

For linear and reciprocating dynamic sealing applications

Example of installed buffer seal
Installed buffer seal example
Buffer seal

Buffer seals are typically uni-directional rod seals that work in conjunction with the secondary rod seal to absorb pressure spikes.More Info…

The primary buffer seal provides the majority of the rod sealing performance while allowing fluid to pass by onto the secondary rod seal. At the same time, they enable trapped fluid sealed by the secondary rod seal, which is downstream of the buffer seal, to be pumped back into the system on the return stroke. When a buffer seal is used in combination with one of our Long-Life Rod Seals, the resulting sealing system provides long life with an exceptionally dry rod. Buffer seals are typically used for rod seal application only.

High-Pressure Buffer Seals up to 5,000psi (350bar)*

Typical Applications

Linear, reciprocating dynamic sealing applications

Operating Range

Maximum Pressure: up to 5,000psi (350bar)*. For pressure above 3,800psi (260bar), please contact engineering for clearances. Pressure ratings can be increased by reducing clearances. Sealing ultra-high pressures can be achieved by replacing the low-friction PTFE/Teflon® sealing element with high-strength polymer materials.

Surface Speed: up to 13ft/s (4m/s)*

Temperature: -40°F to 400°F (-40°C to 210°C) depending on material

Materials: PTFE/Teflon ®, high-performance polyurethanes, low- and high-temperature grades, FDA-compliant seal material grades and proprietary specialized Duralast™, Duraloy™, and Permachem™ compounds.

Availability: More Info…

Most standard or non-standard and application-specific designed buffer seals, in inch or metric sizes, are available with a 2-4 day turnaround.

Application-specific and proprietary seal designs are available. Please contact engineering to get the best seal for your rod buffer sealing applications.


Applications & Industries   

AHPSeals’ seals are currently in successful service in the following industries:

  • Hydraulics
  • Steel Works
  • Government, Military and Defense
  • Abrasive Substance Pumps and Valves
  • Pharmaceuticals
  • Can and Package Filling Machines
  • Oil-Field Exploration and Production
  • Paint and Solvent Manufacture and Application
  • Adhesives Dispensing Valves and Cylinders
  • Chemical Pumps
  • Cryogenic Liquid Control Components
  • Liquid Handling Swivel Joints
  • Construction Equipment
  • Drilling Equipment
  • Chemical Pumps and Valves
  • Heavy Mobile Equipment
  • Mining
  • Rubber and Plastics
  • Presses
  • Food Processing
  • Space Exploration
  • Marine
  • Tire Production
  • Vacuum Service
  • Automotive Plants
  • Pharmaceutical Production
  • Domestic Goods Production
  • Many other applications

*Maximum values depend on seal material, seal configuration, media, temperatures, pressures, surface speed, dynamic running surface finish and working environment.  Data provided are guidelines for ideal operating conditions.  Seals cannot be operated at their upper pressure and speed ratings at the same time.  For maximum seal life expectancy, do not operate your seal beyond 75% of any of its operating limits. Please consult engineering or call 1-800-283-7140 for advice.


American High Performance Seals assumes no obligation or liability for any advice furnished or results obtained with respect to these products. All such advice is given and accepted at the buyer’s risk.

This information, based on our experience, is offered as part of our service to customers. It is intended for use by persons having technical skill, at their own discretion and risk. We do not guarantee favorable results, and we assume no liability in connection with its use.


Any purchases resulting from information provided by American High Performance Seals, Inc., including proposals, recommendations and quotes, are subject to “AHPSEALS TERMS AND CONDITIONS OF SALE.”