Definition - What does U Seals mean?
U Seals, also known as U cups are U-shaped seals that have an inside dynamic sealing lip and an outside static sealing lip to seal rods or pistons. They are named after the alphabet letter “U” because of their cross section shapes which look like distinctive U shapes when looked from the side or front views. The lips of the seals are also U-shaped, which helps in energizing the sealing effect as the pressure increases.
Petropedia explains U Seals
U seals can be used for both static and dynamic pressure sealing applications. There are many types of designs that are available for the U seals such as:
- Loaded U cups
- Unloaded Urethane U cups
- Homogeneous U cups
- Z seal U cups
- Spring Energized U cups
The selection criteria for the U shaped seals depends on various reasons such as the sealing requirements, the resistance to wear and extrusion gap and the resistance to high and low temperature, etc.
These types of seals are available in variety of materials such as:
- Low temperature Nitrile
- Virgin PTFE