Piston Seals - Single Acting

Piston Seals – Single Acting

Single-Acting Piston Seals are used in one-directional, displacement type hydraulic cylinders where pressure is applied from one side only. Single-Acting Cylinders rely on gravity or a spring to return the rod to its original position.

A vehicle hoist is a common example of a Single-Acting cylinder.

Many Single-Acting cylinder designs will only have hydraulic oil on one side of the piston, where the opposing side of the cylinder will be open to the atmosphere. In this, the open end of the cylinder will push in and draw out air which will generally carry contaminants which can cause premature wear and failure of the seal as well as corrosion to the cylinder. Consideration should be given to the external environment when selecting the correct Single-Acting seal for a particular application.

We have an extensive selection of Single-Acting Piston Seals including conventional Polyurethane U-Seals such as the XPSJ or XPSE design which are dual purpose Rod and Single-Acting Piston seals or the Piston specific designs. Piston Cup designs such as XPSK and XPSH seal are a popular variety of dedicated Single Acting piston seal.