Hydraulic directional control valves operate in punishing environments, circulating fluids that generate significant heat through fluid friction and continuous shear. To guarantee long-term fluid retention, our 58x10mm end caps are injection-molded utilizing a specialized, high-density Nitrile Butadiene Rubber (NBR) matrix.

This advanced formulation is strictly engineered to handle continuous exposure to standard mineral-based hydraulic oils (HLP/HM), water-glycol fluids, and petroleum greases at operating temperatures up to 100°C. The heavy rubber jacket acts as a permanent vibration dampener, ensuring the plug will not back out over millions of valve actuation cycles, while providing total immunity against external atmospheric rusting.

Striking the center of the 58*10mm cap will cause the internal metal skeleton to cave inward. This deformation instantly pulls the outer diameter away from the bore wall, completely destroying the radial interference fit and guaranteeing a static hydraulic leak. Technicians must use a heavy-duty, flat installation mandrel that distributes force perfectly across the extreme outer edge of the seal. Wiping a very light film of system-compatible hydraulic oil on the rubber OD prior to installation prevents the elastomer from binding, rolling, or shearing against the manifold chamfer during the press-fit operation.