Polyurethane seals are one of the more common and durable materials in fluid dynamic seals, such as pump shaft seals, hydraulic cylinder pistons, and piston rod seals. This material has a wide range of chemical formulations, making it suitable for a wide range of working conditions.

 

 

 

1. High strength and toughness

Due to its good hardness and toughness, polyurethane seals have excellent resistance to compression. In addition, excellent hydraulic seals must also be able to resist shear and tear, as hydraulic oil can easily break through the defense line of inferior seals under pressure.

Polyurethane will deform under pressure to adapt to changes in gaps and ensure reliable sealing; After the pressure is relieved, its high-strength characteristics can restore it to its original shape instead of causing permanent deformation.

2. High wear resistance

Oil contamination is a common symptom of hydraulic systems. When particles erode seals, there is a risk of premature failure. Polyurethane benefits from its natural high wear resistance, especially compared to other polymers such as nitrile rubber and fluororubber, which are much better.

3. High temperature resistance

Under high temperature conditions, polyurethane is still a must-have for high-pressure hydraulic systems. Polyurethane has a rated temperature of over 120 ℃ and can withstand pressures of 5000 psi or even higher. This extreme combination makes polyurethane a leader among similar hydraulic cylinder products. Although fluororubber can easily handle temperatures above 200 ℃, its pressure bearing capacity is poor, usually limited to 2000 psi or even lower.

4. Processability

Due to the fact that polyurethane seals are not poured or molded from liquid base materials, but can be directly machined on CNC lathes, they can be processed into more complex shapes.