Hydraulic and Pneumatic Seal Information

Types of Seals

  • Rod Seals

  • Piston Seals

  • Vee Packs

  • Wipers

  • Wear Rings

  • Unitized Piston

  • Unitized Gland

  • Buffer Seals


Hydraulic seals are designed for high-pressure dynamic applications such as hydraulic cylinders. Pneumatic seals are used in pneumatic cylinders and valves that are generally designed for lower operating pressures than hydraulic seals. Pneumatic applications also typically demand higher operating speeds and lower friction seals than hydraulic applications. 

Rod Seals

The rod seal is the most critical seal on any type of fluid power equipment preventing leakage of fluid from within the cylinder to the outside. Leakage through the rod seal can reduce equipment performance, and also in extreme cases can cause environmental issues.

Piston Seals

Piston Seals are used in hydraulic cylinders for fluid sealing and are designed to ensure that pressurized fluid does not leak across the cylinder head as the system pressure pushes the piston down the cylinder bore. 

The choice of piston seals is decided by the way in which the cylinder operates. For a single acting cylinder, you are sealing dynamic pressure from one side (unidirectional), it is always best to choose the type of seal designed to provide optimum sealing qualities for single-acting functions. 

The best sealing capacity of a double-acting cylinder, capable of sealing dynamic pressure from both sides(bidirectional), is achieved by choosing a double-acting seal.

Piston Seals, both single and double acting, can be designed for and used with integrated or separate back-up rings and guide rings.



Vee Packs


At VB Seals we are committed to providing our customers with the most advanced, cost effective sealing solutions available in the market. Our experienced staff is dedicated to premier service through distribution.


Tel: 515-292-6065 | Fax: 515-292-6250

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1107 Airport Rd.

Ames, IA 50010