Construction machinery is inseparable from the cylinder, and the cylinder is inseparable from the seal. A common seal is a seal ring, also called an oil seal, which acts as a barrier to oil and prevents oil from escaping or passing. Common types of seals for hydraulic cylinders are of the following types: dust seals, piston rod seals, cushion seals, guide support rings, end cap seals and piston seals. The dust ring is installed on the outer side of the hydraulic cylinder end cover to prevent external contaminants from entering the cylinder, and can be divided into a snap-in type and a press-in type according to the installation method.

The piston rod seal ring is also called the U-shaped cup. It is the main piston rod seal. The Teflon dust-proof cylinder seal ring manufacturer is installed inside the hydraulic cylinder end cover to prevent hydraulic oil from leaking. The piston rod seal is made of polyurethane or nitrile rubber. In some cases, it needs to be used together with a support ring (also called a retaining ring). The support ring is used to prevent the seal ring from being crushed under pressure. There are also many variations of the piston rod seal. The piston seal is used to isolate the two chambers of the hydraulic cylinder and is the primary seal within the hydraulic cylinder. Usually two-piece, the outer ring is made of Teflon or nylon, and the inner ring is made of nitrile rubber. There are also a number of variations, including the use of bronze coated with Teflon. In single-acting cylinders, polyurethane U-shaped cups are also used.