Among the reciprocating sealing components of hydraulic cylinders, the V‑ring is a critical sealing element. It directly affects the sealing performance of the cylinder, equipment failure rate and overall service life. Many customers are confused during material selection: whether to choose rubber or polyurethane for V‑rings.

Considering actual working conditions, polyurethane is preferred for applications requiring wear resistance. Neoprene rubber adapts to various chemical media and high‑temperature environments. Polyurethane rubber delivers outstanding wear resistance and is well‑suited for hydraulic cylinders with frequent reciprocating motion. Nevertheless, the procurement cost of polyurethane materials is higher than that of ordinary rubber.

V‑rings are available in a wide range of materials. Nitrile butadiene rubber (NBR) and neoprene rubber are the most commonly used materials on the market. Natural rubber is mainly used for sealing water and air media. Butyl rubber is compatible with special media such as non‑flammable hydraulic oils and phosphate‑ester‑based hydraulic fluids.

The biggest advantage of ordinary rubber seals is their cost‑effectiveness, offering obvious cost benefits compared with polyurethane. However, they also have notable drawbacks: poor wear resistance and inferior long‑term anti‑ageing performance. They wear rapidly under high‑pressure and high‑frequency reciprocating conditions and require regular inspection and replacement.

Polyurethane V‑rings feature excellent tear resistance and extrusion resistance. They are compatible with mineral‑based hydraulic oils and possess good dimensional stability. Under high‑pressure conditions, they are not easily squeezed into sealing clearances by hydraulic oil, providing reliable sealing and extended service life, which effectively reduces equipment downtime and maintenance frequency. Nonetheless, polyurethane has temperature limitations. Standard products operate within ‑20 ℃ to +80 ℃. They are not suitable for special media including phosphate ester fire‑resistant hydraulic fluids, and will harden in low‑temperature environments, resulting in degraded sealing performance.