There are several types of sealing rings

Sealing rings can be classified into various types based on material, shape, and direction of action.


According to the material of the sealing ring, it can be divided into metal sealing ring, nitrile rubber sealing ring, CR chloroprene rubber sealing ring, natural rubber sealing ring, fluororubber sealing ring, silicone sealing ring, EPDM sealing ring, polyurethane rubber sealing ring, chloroether rubber sealing ring, acrylic rubber sealing ring, butyl rubber sealing ring, styrene butadiene rubber sealing ring, etc.


According to the shape of the sealing ring, it can be divided into V-shaped sealing ring, U-shaped sealing ring, O-shaped sealing ring, rectangular sealing ring, Y-shaped sealing ring, YX-shaped sealing ring for holes, YX-shaped sealing ring for shafts, and J-shaped frameless dust ring.


According to the direction of action of the sealing ring, it can be divided into dustproof sealing ring, piston rod sealing ring, buffer sealing ring, guide support ring, end cover sealing ring, and piston sealing ring.


The dust ring is installed on the outer side of the hydraulic cylinder end cover to prevent external pollutants from entering the cylinder. According to the installation method, it can be divided into snap in type and press in type.


The most common type of dust ring is the snap in type. As the name suggests, the dust ring is stuck in the groove on the inner wall of the end cover and is used in less harsh environmental conditions. The material of the snap in dust ring is usually polyurethane, and there are various variations in its structural form, such as the double lip structure of the H and K sections, but it never changes.


The pressure type dust ring is used under harsh and heavy load conditions, not stuck in the groove, but wrapped with a layer of metal outside the polyurethane material to increase strength, and pressed into the hydraulic cylinder end cover. There are also various forms of pressed in dust seals, including single lip and double lip.


The piston rod seal ring, also known as a U-shaped cup, is the main piston rod seal installed on the inside of the hydraulic cylinder end cover to prevent hydraulic oil leakage. The piston rod sealing ring is made of polyurethane or nitrile rubber, and in some cases, it needs to be used together with a support ring (also known as a retaining ring), which is used to prevent the sealing ring from being squeezed and deformed under pressure. There are also various variants of piston rod sealing rings.


The buffer sealing ring serves as an auxiliary piston rod sealing ring to protect the piston rod in the event of a sudden increase in system pressure. There are three common types of buffer sealing rings. Type A is a single piece sealing ring made of polyurethane. The B and C types are two-piece, used to prevent seal compression and allow the seal to withstand higher pressure.


The guide support ring is installed on the end cover and piston of the hydraulic cylinder to support the piston rod and piston, guide the piston to move in a straight line, and prevent metal to metal contact. The materials include plastic, bronze coated with polytetrafluoroethylene, etc.


The end cap sealing ring is used to seal the end cap and cylinder wall of the oil cylinder. It is a static seal used to prevent hydraulic oil from leaking out from the gap between the end cap and cylinder wall. Usually composed of nitrile rubber O-rings and support rings (retaining rings).


The piston sealing ring is used to isolate the two chambers of the hydraulic cylinder and is the main seal inside the hydraulic cylinder. Usually two piece, the outer ring is made of polytetrafluoroethylene or nylon, and the inner ring is made of nitrile rubber. There are also various variants, including the use of bronze coated with polytetrafluoroethylene, and so on. On single acting cylinders, polyurethane U-shaped cups are also used.


FOREVER SEALS can provide various types of seals.

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