Description

Hydraulic seals and pneumatic seals are designed as per the cylinder working pressure, cylinder speed, operating temperature, working medium and application.

Hydraulic seals are generally relatively soft, non-metallic rings captured in groove or fixed in a combination of rings, forming a seal assembly, to block or separate fluid in reciprocating motion applications. Hydraulic seals are vital in machinery. Their use is critical in providing a way for fluid power to be converted to linear motion. Not only must the hydraulic seals prevent leakage of fluid from the Cylinder, but hydraulic seals must also withstand high pressures, extreme temperatures and transverse forces within the cylinder. In such applications, the function of Hydraulic Seals goes far beyond preventing fluid leakage.

Hydraulic seals can be made from a variety of materials such as polyurethane, rubber or PTFE. The type of material is determined by the specific operating conditions or limits due to fluid type, pressure, fluid chemical compatibility or temperature.

A static hydraulic seal is located in a groove and sees no movement - only sealing within its confined space, acting like gasket.

A type of dynamic hydraulic seal called a rod seal is exposed to movement on its inner diameter along the shaft or rod of a hydraulic cylinder. A type of dynamic hydraulic seal called a piston seal is exposed to movement on its outer diameter along the tube or bore of a hydraulic cylinder.

A hydraulic seal is used to contain fluids and maintain the hydraulic pressure (piston seal, rod seal, back-up ring), to stop the inlet of impurities and to preserve the lubricating film on the rod (wiper seal) and to resist any deformation under a radial load by guiding the piston and rod (wear ring and guide strip).

Nextgen Tech has a complete range of hydraulic seals and we can also assist you in creating custom-made seals for linear and static hydraulic applications.

Seal Functions

Each dynamic seal in a hydraulic cylinder has a special function to contribute to the performance of the system.

Piston Seal Functions

Acts as a pressure barrier and prevents fluid passing the piston; important for controlling the cylinder motion or maintaining the position at rest

Rod Seal Functions

Act as a pressure barrier and keeps the operating fluid inside the cylinder

Regulates a film of fluid on the surface of the piston rod as it extends; important to inhibit rod corrosion and lubricate the wiper and rod seal itself

Accept the lubrication film back into the cylinder when the rod retracts

Buffer Seal Functions

Protect the rod seal from fluid pressure spikes in excess of system pressure

Attenuate the fluctuations in system pressure, thereby improving rod seal performance by allowing the rod seal to deal with more constant or gradually changing pressure

Act as an internal excluder to keep system contaminants, such as metal particles from damaging the rod seal

Wiper Seal Functions

Prevent external contaminants from entering the cylinder assembly and hydraulic system (pump, reservoir etc)

Accept the lubrication film back into the cylinder when the rod retracts

Guide Rings (rod and piston) Functions

Prevent metal to metal contact between components

React to radial loads caused by side loads on the cylinder assembly