Why do hydraulic cylinders need to be equipped with a wiper seal?

What’s the first line of defense for a hydraulic cylinder against dirt, moisture, and debris? The often-overlooked wiper seal is a tiny component with an outsized impact on performance. If there is no wiper seal, dust will seep into the hydraulic cylinder, not only wearing out the seals but also greatly damaging the guide sleeve and piston rod, which will have a very significant impact on the hydraulic cylinder. In addition, it may also lead to impurities entering the hydraulic medium, which will affect the functions of the operating valves and pumps, and also damage these devices. Therefore, all hydraulic cylinders need to be equipped with wiper seals.

What is a wiper seal?

The wiper seal is a critical component that excludes contaminants from the hydraulic cylinder, safeguarding internal parts from wear and damage. It is usually installed on the piston rod to prevent dust, particles, and other impurities from entering the interior of the hydraulic cylinder, thereby keeping the interior of the hydraulic cylinder clean.

How does the wiper seal work?

The wiper seal is stationary mounted at the cylinder head. As the piston rod reciprocates:

During extension, the seal's outer lip scrapes contaminants off the rod surface, while its inner lip maintains hydraulic fluid retention.

During retraction, the seal's flexible design allows it to conform tightly to the rod, ensuring continuous exclusion of external debris.

This dual-action sealing prevents both ingress of contaminants and egress of hydraulic oil, which is critical for cylinder longevity.

The wiper seal can be classified into various types based on their materials and structures

Common types of wiper seals include nitrile rubber (NBR), polyurethane (PU), and fluorocarbon rubber (FKM) variants. Each material type exhibits distinct performance characteristics, making them suitable for different operating environments and application requirements.

The correct selection and installation of dust-proof rings are very important for hydraulic cylinders. The hydraulic cylinders produced by TOLENG are equipped with high-quality dust-proof rings, each of which is meticulously crafted. We can also provide professional maintenance and care for your cylinders. Please contact us at sale01@phtl.cn