These seals are typically found in hydraulic system applications that involve a rod and piston. The most common types of hydraulic seals include piston seals, rod seals, buffer seals, wear rings, wear bands, and wiper or scraper. Each sealing component is vital to a smooth-operating hydraulic cylinder.
Rod seals are used in hydraulic and pneumatic cylinders to seal the system pressure on the rod side against the atmosphere. Specifically, they seal the pressures during the stroke phase of the application.
Piston seals separate applied pressures between the piston and rod side during stroke movement and during the interim and final position. They are available as single-acting, double-acting, and complete pistons. A wide range of compound and profile configurations is available to meet specific application profiles.
Wipers are designed to prevent any contamination to the system by external media during stroke movement of the cylinder. Wipers also provide static sealing function to the cylinder head versus the atmosphere. Some wipers have an additional lip to prevent contaminant ingression.
Wear bands or wear rings are used to prevent metal-to-metal contact. Wear bands are also used to guide the piston and the rod during the stroke phase to prevent any side-loading.
Buffer seals are found primarily in heavy duty, hydraulic applications to absorb pressure fluctuations during high load conditions. Buffer seals are used in tandem with rod seals.