Hydraulics and Hydraulic Tools


The article gives you details about the hydraulic seals , a component in the hydraulic systems.


Small but Important Part - Oil Seal

Oil seal is an important part of the hydraulic system. It is so important that without it the hydraulic system will come to a standstill. It is an engineered component of the system. The materials of the oil seal play an important part in selection of the seal.


Material of Oil Seals

The major materials used in the manufacture of oil seals are silicone, nitrile rubber, butyl rubber, hypalon, Teflon, and styrene butadiene. Natural rubber is also used in manufacture but the use is decreasing in its natural form. It is being used more as an additive rather than the 100% material. The spring in the oil seal for making a leak proof joint is also being given the consideration that it deserves. The spring is generally made from stainless steel, as it does not react with most hydraulic oils.

The Function of Oil Seal

The function of oil seal is to prevent leakage of oil when the system is being pressurized to the full pressure and also when the piston is moving inside cylinder. The seals are made in such a manner that the hydraulic pressures when applied on the seal they tend to close the seal against the surface rather than opening up. So the pressure actually aids the in sealing oil leakage.

Reasons for Seal Damage

Since the seal is an important part of the hydraulic system, it is necessary to know why a seal gets damaged in order to prevent the seal damage. The major reasons of seal damage are,

1.     Dirt in the oil: Dirt in oil is one of the major reasons for seal damage. The dirt intrusion in the system can take place when the systems are being attended and improper maintenance techniques are used. Infrequent cleaning of the oil storage and use of improper cleaning methods can also contribute to a dirty oil in the system

2.      High temperature of oils: The oil system generally has a cooling mechanism as part of oils supply. If this cooling system breaks down for some time, the oil temperature may rise and weaken the oil seal material particularly if the oil seal has been in use for some time and the natural rubber is a part of the seal material.

3.      Improper fitting of seal: If the seal has not been fitted properly, the oil seal will start leaking after sometime as the components which are designed for sealing will start wearing out faster and the seal will have a premature failure.

When you purchase a seal for replacement make sure that the seal you are purchasing is an exact replacement for the seal. Making a compromise can be disastrous at a later time. A seal is not a costly item in the hydraulic system, but if you try to compromise on the seal cost, you may have to pay for it dearly later. The cost cutting does not pay incase of oil seals. The policy of “save now repent later” can be adopted only at your peril.