seals product

Piston Seals

Piston Seals

Quick Contact for Piston Seals


W4650 Physical Properties

  Physical Property   ASTM Test Method   Values
  Tensile Strength   D-638   17,000-23,000 PSI
  Compressive Strength   D-695   21,000-28,000 PSI
  Flexural Strength   D-790   23,000-30,000 PSI
  Water Absorption   D-570   50-.70%
  Elongation   D-638   3-10%
  Tensile Modulus   D-638   900,000 PSI
  Shear Strength   D-732   10,000-12,000 PSI
  Flexural Modulus   D-790   870,000-1,000,000
  Hardness, Rockwell   D-785   119-121 R 94-96 M
  Deformation Under Load (2000 PSI @ 122° F)   D-621   .2-.4%

Code-Compliant Hydraulic and Pneumatic Piston Seals

Valley Seal is your trusted source for the widest variety of piston seals for both, hydraulic and pneumatic applications. Irrespective of the seal type you choose, our seals provide definitive advantages over competing products. Our seals are among the most durable ones on the market today, securing high-pressure systems effortlessly.

Pneumatic Piston Seals

Whether you need seals for basic applications or for high-temperature abrasive environments, our seals are designed to provide successful service. Having been in the industry for several decades, we know the seal designs and materials that work best. Our seals demonstrate excellent wear resistance in pneumatic cylinders and valves. They are designed for lower operating pressures than hydraulic seals, and are suitable for use in rotary as well as reciprocating motion.

Hydraulic Piston Seals

When you need unfailing protection in your heavy-duty hydraulic applications, look no further than Valley Seal for the best products on the market. We carry a special range of seals designed especially for use in hydraulic applications subjected to high pressures and temperatures. Valley Seal offers the industry-trusted OK sealing assembly that is suitable for working pressures up to 7250 PSI (500 bar) and above in some specific situations. The Piston Seals OK Profile is an effective and less expensive alternative to costly capped T-Seals and PTFE loaded cap seals. We can also honor your unique seal requirements for pneumatic and hydraulic fluid sealing applications. Please speak with Valley Seal engineers or sales correspondents for assistance with your piston sealing requirements.

Field of Application

Working pressure: 7250 psi (500 bar)
Working temperature: -40° F to 250° F
Surface speed: 3.28 f/s (1 m/s)

Ease of Installation

This durable two-piece seals are designed to be compressed in the bore upon installation to minimize seepage at the gap. The OK piston seals split design facilitates its installation on solid pistons without the necessity of auxiliary tools. The OK Profile can be snapped into closed-groove spaces. Note: The installation groove must be carefully deburred and cleaned of all foreign material. The cylinder bore must have a leading edge chamfer.

Compound Formulated to Extend Seal Life

The cylinder seal ring is produced of W4650, a glass reinforced nylon. The tensile strength and flexibility exhibited by W4650 provides maximum stretch during installation. Other beneficial characteristics of this material include the ability to capture and contain system contaminants such as metal chips, excellent compressive strength and the ability to resist extrusion or chipping when passing over cylinder ports. (See W4650 Physical Properties Table)

Expander Ring

This is an NBR-based elastomer with 70 shore A hardness. The rubber expander ring provides good compression set resistance which in turn increases potential seal life.