Modular sealing concept enhances pneumatic cylinders

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Modular sealing concept enhances pneumatic cylindersRexroth's Modular Sealing Concept for PRA/TRB ISO 15552 pneumatic cylinders enables machine builders to specify a seal and scraper module that matches the application requirements. Not only does this provide improved performance, but it also reduces the cost of ownership because of a much longer seal life and simple and quick replacement of the seal cartridge. Rexroth claims that its modular sealing concept is unique in this market.

Depending on the operating environment, the requirements for scrapers and seals can vary considerably. For that reason, Rexroth is offering three alternative scrapers in its modular sealing concept, each with tight tolerances for a close fit on the piston rod:

  • Metal (brass) for applications in which hard materials might adhere to the piston rod, with operating temperatures up to 120degC
  • Carbon-filled PTFE for applications requiring chemical resistance and operating temperatures up to 120degC
  • Higher-strength PEE for use in dusty environments

Rexroth explains that specifying a scraper to match the application requirements results in a better scraping action and, therefore, longer life for the seal. More information about the scrapers is available at

The Modular Sealing Concept is based around a cartridge containing the scraper, piston rod seal and a double bearing for supporting and guiding the piston rod. This cartridge is easily removed and replaced by means of a standard spanner, with no need to dismantle the cylinder or remove it from the machine. For operating temperatures of -20 to +80degC the minimum service life is 5000km. Because the seal module can be replaced on its own - and quickly and easily - the cost of ownership is considerably lower than when using cylinders that either cannot have the seals replaced or that have to be removed and dismantled for maintenance.

Rexroth has published details for which scraper is best for use in various industries - such as paper/printing, welding and food processing - or the company's application engineers can recommend scrapers to suit particular operating conditions. The Modular Sealing Concept is available on Rexroth PRA/TRB pneumatic cylinders that conform to the dimensions in the inernational standard ISO 15552 (bore sizes from 32 to 125mm and stroke lengths up to 2800mm); these cylinders feature aluminium cylinder tubes, stainless steel piston rods, die cast aluminium end covers, and zinc-plated steel piston rod nuts. The cylinders and replacement seal modules are available from stock with free delivery within the UK.

Follow the link for more information and to view a short animation about the Rexroth modular sealing concept for pneumatic cylinders.

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