Wiper Seals, also known as Scraper Seals or Dust Seals are primarily designed to prevent contaminants from getting into a hydraulic system. This is usually achieved by the seal having a wiping lip that essentially cleans away any dust, dirt or moisture from he rod of a cylinder on each cycle. Hydraulic rod seals consist of a metal rod inserted in a rubber or plastic sealing element. The sealing part conforms to the rod surface, creating a tight seal that prevents internal pressure from escaping and external contaminants from entering the cylinder.