75-toolbar-shop Shop
37-ecat E-Catalog
80-services Services
25-download Downloads
35-contact Contact
Piston Seals

Piston Seals

Dynamic and Static Sealing of the Piston Against the Cylinder Barrel

To build up pressure in the piston chamber, piston seals seal the piston against the cylinder barrel. Due to the wide range of requirements in hydraulic applications (such as pressure, pressure peaks, sliding speeds, temperatures, and process media) choosing the right piston seal is very important. The Dichtomatik product brand portfolio offers a wide range of elastomer and thermoplastic seals, such as the K, KK, KNA, KPOR, or N series. The piston seals are used for hydraulic cylinders in mobile hydraulics, agricultural machinery, construction machinery and presses.

Benefits at a Glance

  • Broad range of product types and materials
  • Temperature and media resistant
  • Very good wear behavior by reduced friction and therefore good lifetime
  • No stick-slip effect
  • Single- and double-acting piston seal types
  • Symmetrical and asymmetrical piston seal designs
  • Product types for especially high loads
  • Very good price-performance ratio
  • Suitable for many industrial applications

Important note: Dichtomatik products comply with common industrial standards and therefore are suitable for many applications excluding safety-critical ones like Automotive. Premium Freudenberg products are the right choice for all applications ensuring highest quality and safety standards and therefore optimal total cost of ownership.

Piston Seals

Choose the Right Product

Out of Six Types

  • KNA series: asymmetrical U-ring for one-sided pressure load
  • N series: symmetrical U-ring being suitable for one-sided pressure load (can also be used as a rod seal)
  • KPOR series: combination of a PTFE-bronze sealing element and an O-ring (NBR) that serves as a pre-tensioning element
  • KK series: compact seal consisting of a sealing element combined with a backup ring and a guide element
  • KDS01: three-part sealing system for one-sided pressure load with pressure- and back-up ring as well as V-packing made of NBR fabric
  • K series: double-acting piston seals made of TPU and an elastomeric pre-tensioning element. (K70 with an O-ring and K84 with a rectangular ring)

Please note that resistances, pressures and temperatures are mutually influenced by various parameters.

    Related Documents

  • Brochures 66-plus 67-minus


    Product Overview - Dichtomatik Brand

    Tailor-Made Seals and Service Portfolio

    English | PDF | 4228 KB


    Hydraulic brochure

    Information about sealing solutions for hydraulic applications, which are mainly used to seal reciprocating moving components.

    English | PDF | 2833 KB

  • Solutions Sheets 66-plus 67-minus


    Piston Seals

    Piston seals have the function of sealing the piston against the cylinder tube to ensure a pressure buildup in the piston chamber. Here the sealing material and the profile of the piston seal must be selected on the basis of the application and the conditions of use.

    English | PDF | 224 KB

Product Portfolio

Sealing products setting benchmarks

Premium products and individual sealing solutions of the Freudenberg brand are the perfect choice for any application. Uncompromising quality (0-defect strategy) and excellent performance ensure full safety and optimized total cost of ownership (TCO).

Freudenberg Piston Seals 70-external-link