Rod & Piston seals are equal lip-seal which can be used for both piston seal and rod seal. Rod & Piston seals are equal lip-seal which can be used for both piston seal and rod seal. They’re also the most critical seals on any type of fluid power equipment preventing leakage of fluid from within the cylinder to the outside. Leakage through the rod or piston seal can reduce equipment performance, and also in extreme cases can cause environmental issues. .