Fluid Power Sealing Solutions

Hydraulic fluid power systems use pressurized fluid to transfer energy in construction machinery, aerospace, automotive and other equipment. Hydraulic seals help prevent leakage and external contamination while supporting reliable operation in cylinders, pumps, motors and valves. For product selection and purchasing, use the dedicated Hydraulic Seals & Pneumatic Seals category.

Seal Types Used in Fluid Power Systems

Static seals: used for sealing between fixed parts, such as flange connection, cover plate, valve body and so on.

Dynamic seals: used for sealing between relatively moving parts, such as piston and cylinder, shaft and bearing.

Rotary seals: specially used for sealing rotating shafts, such as shaft seals of pumps and motors.

Seal Material Selection for Fluid Power Systems

Rubber seals: such as nitrile rubber (NBR), fluorine rubber (FKM), polyurethane rubber (AU/EU), etc., with good elasticity and oil resistance.

Polymer seals: such as polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), etc., with excellent chemical resistance and high temperature resistance.

Metal seals: such as stainless steel, copper, aluminum, etc., used for sealing under high temperature, high pressure or special environment.

Composite seals: combining the advantages of metal and polymer, such as metal-coated rubber, filled polytetrafluoroethylene (PTFE), etc.

How to Select Seals for Fluid Power Systems

Pressure resistance: the ability to maintain a seal in high-pressure environments, where the pressure in hydraulic systems is typically high.

Abrasion resistance: due to the relative motion of components in the hydraulic system, seals need to have good abrasion resistance.

Temperature resistance: the ability to maintain performance over a range of system operating temperatures, the operating temperature of the hydraulic fluid may range from low to high temperatures.

Chemical resistance: the ability to resist chemical corrosion of the hydraulic fluid.

Low friction: Reduces energy loss and improves system efficiency.

Reliability: the seal must maintain its function without leakage during its design life.

Manufacturing process

Molding: for the manufacture of rubber and certain composite seals.

Injection molding: applicable to the manufacture of certain plastic seals.

Machining: Suitable for the manufacture of metal and polymer seals.

Testing and verification

Leak Testing: Leak testing with hydraulic fluid to ensure that the seals are leak free.

Environmental testing: Seal performance is tested under simulated hydraulic system working environment, such as high temperature, low temperature, vibration, etc.

Life test: Evaluate the service life of seals through accelerated aging test.

Fluid Power Seal Applications

Piston Seal: Used for sealing between piston and cylinder in hydraulic cylinder to prevent hydraulic oil leakage.

Rod Seal: Used for sealing between the piston rod and cylinder barrel in hydraulic cylinders to prevent external contaminants from entering and hydraulic oil from leaking.

Valve seals: used in hydraulic valves to ensure that the switching action of the valve is accurate.

Pump and motor seals: Used in hydraulic pumps and motors to prevent shaft seals from hydraulic oil leakage.

Wiper Seal:Removes dust, mud and other contaminants from the rod before they enter the cylinder.

Pneumatic Seals: Designed for low-pressure reciprocating systems where low friction and stable movement are important.

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