Piston Seals

• Single-acting : Capable of sealing dynamic pressure from one side (unidirectional)
• Double-acting : Capable of sealing dynamic pressure from both sides (bidirectional) The piston seal design ensures a high static sealing force on the inside diameter of the seal. This provides high stability of the seal during operating cycles, eliminating rocking and pumping effects as instability of seals can create leakage and seal damage.

Non-symmetrical Piston Seal Design

• Non-symmetrical piston seals are seals where the shape of the outside diameter lip differs from the inside diameter (see Fig. 1, outside lip shorter than inside lip).
• Non-symmetrical piston seals provided by AHPSeals are not centered in the piston groove and provide sealing contact with the piston across the entire surface of the inside seal diameter.(Fig. 2)
• Non-symmetrical piston seals are more stable and provide better sealing performance than symmetrical seals do.

Lip vs. Squeeze Type Seals

The basic design of a seal significantly affects the overall function of the seal, especially at low pressures. One of the most challenging applications is linear dynamic sealing at low pressure while providing low breakaway and running friction. AHPSeals provides a series of low-friction seals for these challenging applications.

• Lip seals are without any energizing rubber elements; therefore, they provide a more flexible dynamic seal lip and are generally characterized by low friction, low wear and poor low-pressure sealing capabilities.
• Squeeze seals typically incorporate an energizing rubber element and are generally characterized by high friction, high wear and good low-pressure sealing. To avoid a pressure trap between two seals and potential seal failure, do not use energizer loaded seals for back-to-back bidirectional piston sealing applications.