Piston seals or piston rings ensure fluid or other media does not by-pass the piston as the system pressure pushes the piston down the cylinder during a pressure cycle. Piston seals are dynamic seals, generally single-acting (pressure acting on one side only) and double-acting (pressure acting on both sides) seals. The choice of piston seal is determined by the way in which the cylinder operates.

The fabrication materials are based on NBR Perbunan with a hardness of 80 + 5 Shore.

Single-acting pistons only contain pressure on one side of the piston. The seal is required to keep the pressure from one direction, which then moves the piston along the cylinder.

Double-acting pistons contain pressure on both sides of the piston without leakage. They allow maximum mechanical effort to the moving the piston along the bore of a cylinder.