Hydraulic seal Common self sealing compression type hydraulic pressure Sealing element Mainly O-ring , round seal ring And rectangular rings, which have the advantages of simple structure, easy manufacturing, low cost, etc., so they are widely used in the hydraulic transmission system as dynamic sealing elements and static sealing elements. When they are installed in the seal groove, they usually produce 15~25% radial compression deformation and high initial contact stress on the sealing surface, thus preventing the leakage of pressureless liquid.
When purchasing seals for maintenance, most users will purchase them according to the size and color of the samples, which will only increase the difficulty of purchasing, and may not be able to select the appropriate products. The following procedures are recommended to improve the accuracy of seal procurement:
First determine the direction of movement where the seal is located, such as reciprocating, rotating, helical, or stationary.
For example, the pull rod seal that determines the activity point is in the inner diameter or the piston seal that determines the activity point is in the outer diameter.
Consult the instructions of the original machine or evaluate the working temperature according to the actual working environment to determine the materials needed. For the description of temperature class, please refer to the following precautions for production users.
Consult the relevant data from the original machine instructions, or infer the working pressure level by observing the hardness and structure of the original seals. For the description of the pressure level, refer to the following precautions for production users.
Most users will choose and purchase according to the used old samples, but after using for a period of time, the original size of seals will be greatly affected by temperature, pressure, wear and other factors. The selection based on samples can only be used as a reference. A better method is to measure the size of the metal groove where the seals are located, and the accuracy will be higher.
Precautions for production users ： The damage causes of general seals are almost the working requirements of seals:
One of the reasons for the leakage of the seal is that its material is hardened by temperature. When the hardness is too high, the seal cannot fill the gap with the mating parts, which will lead to leakage.
The wear of seals involves the surface finish, movement speed and transmission media of mating parts. Different sealing materials adapt to different movement speeds.
When the seal is subjected to excessive pressure, it will be squeezed into the metal gap, which will damage the seal and cause leakage. This situation involves the hardness of the seal itself and whether the metal gap is too large. If the design, model selection, processing or installation are handled improperly, extrusion damage will occur.
It shows that the seal is softened or even dissolved, because the seal is invaded by the media, and the material selection is wrong. Pay special attention if the media contains water or solvent.
