Buffer seals protect the rod seals by reducing pressure peaks (sudden pressure spikes). Abrupt pressure peaks can occur by external forces acting on the piston rod initiated by the fluid inside the cylinder. These pressure peaks can be far in excess of the system operating pressure. Buffer seals in combination with rod seals provide an effective rod sealing system for cylinders in heavy duty applications at high temperature and pressure
The use of the Buffer Seal will greatly extend the life of the primary rod seal by protecting it from excessive pressure conditions. Pressurized fluid between the Buffer Seal and the primary rod seal is allowed back into the cylinder via the slotted outside diameter rib, flexible outer sealing lip and side wall slots. This relieving function prevents excessive pressure build-up between the Buffer Seal and the primary rod seal, which results in the premature failure of the primary rod seal due to excessive frictional heat build-up and seal extrusion. A high-performance Backup Ring is nested into the Buffer Seal inside diameter to prevent seal extrusion at high pressure and elevated temperatures. Both ID and OD sealing lips are knife trimmed to provide reliable sealing performance.
Seal center hydraulic buffer seals employ an unsymmetrical cross-section design and are often combined with anti-extrusion rings to prevent gap extrusion. State-of-the-art designs include a pressure-relief functionality from the low pressure side, addressing concerns related to drag-oil pressure trapped between the tandem elements. Our comprehensive selection of premium buffer seals are designed for use with hydraulic cylinders, providing excellent wear resistance, and high pressure capabilities. Seal center buffer seals combine advanced polymer materials, such as PTFE or HPU with sophisticated product design.