Double acting piston seals are the most commonly used seals in hydraulic cylinders. The benefit of a double acting piston seal is its ability to be pressurised from both directions whether it be fluid or air. This allows the rod to retract back and forth.
Double acting piston seals have a symmetrical profile allowing the seal to have identical sealing properties in both directions. The are two standard pistons: a two part piston arrangement, more commonly known as split piston, or a one piece solid piston. Double acting piston seals come in a variety of different profiles to suit different sealing applications including, low, medium or heavy duty.
Double acting piston seals can be a simple, yet effective, two piece piston seal arrangement consisting of a glide element and an energizer which is typically NBR (Nitrile Rubber) to allow for deformation. Once the glide ring is installed over the rubber element it provides adequate preload to keep the piston seal in direct sealing contact with the cylinder bore.
Piston seals have also been designed as a five piece set incorporating the main centre seal which holds pressure and prevents fluid bypass from the opposing cylinder chambers. There are also two back-up rings on either side to help support the centre seal in pressure peaks as well as two guide rings on the outside to support any side load in the cylinder bore.
Sealnet stocks the worlds largest range of Double Acting Piston seals in a wide range of various profiles and sizes. Various Materials available for different operating conditions and applications.