Spring Energized U-Cups

Imperial & Metric

Spring Energized U-Cups are engineered plastic seals which incorporates a metallic spring. The spring loads the seal lips against the mating hardware, creating a seal capable of compensating for movement in dynamic applications. The spring provides the necessary lip squeeze to compensate for movement in dynamic applications. Spring Energized U-Cups are normally used in single acting dynamic applications and should be oriented with the spring cavity towards the pressure side. Pressure from the media being sealed provides additional sealing force as it acts upon the sealing lips.

Spring Energized U-Cups are typically used in applications where conventional elastomers are not acceptable due to application conditions such as:

Media Compatibility
Friction Sensitive Application
Dynamic Sealing of Abrasive or
Non- Lubricating Media

Temperature Extremes

High Surface Speeds

High PV Rates (Pressure x Velocity)

Explosive Decompression

Due to the high performance requirements of the Spring Energized U-cups, most Spring Energized U-cups stocked by Hi-Tech Seals are custom designed parts. Hi-Tech Seals can provide engineering support for seal design on demanding applications. Please contact a Hi-Tech Seals' sales representative with your questions and/or application requirements.

Selecting a profile:

1. Select the best dynamic lip
2. Decide if the lip is appropriate for the static lip. The Spring Energized U-Cup profile does not have to be symmetrical.
3. Select a spring:

A cantilever spring is recommended for dynamic, medium load applications where low friction is desired. A helical wound spring is preferred for static applications or applications where sealability is more of a concern than friction.

Seal Type	Advantages	Disadvantages
	Low wear rate Preferred design for oscillatory, slow rotary applications Radius lip reduces probability of seal lip damage during installation	Should not be used for dynamic sealing of abrasive media May weep in high speed reciprocating applications due to seal lip hydroplaning
	Improved sealability, prefered design for dynamic sealing of gas/vapor Beveled lip reduces probability of seal lip damage during installation	Should not be used for dynamic sealing of abrasive media May weep in high speed reciprocating applications due to seal lip hydroplaning
	Locks seal into reduced glands Reduced probability of seal lip hydroplaning Low wear rate Good excluder for debris/contamination	Requires good lead-in chamfer if hardware is installed lip first Possible weepage of light fluids or gases
	Low wear rate Redundant seal lip design Trapped fluid between contact points provides added lubrication to seal	Should not be used for dynamic sealing of abrasive media May weep in high speed reciprocating applications due to seal lip hydroplaning
	Improved sealability over D style lip Preferred lip design for dynamic sealing of abrasive media Reduced probability of seal lip hydroplaning	Requires good lead-in chamfer if hardware is installed lip first Lip design must be used in combination with other lip style
	High Load of helical wound spring improves sealability Suitable for sealing cryogenic gases and fluids Radius lip reduces probability of seal lip damage during installation	Should not be used for dynamic sealing of abrasive media May weep in high speed reciprocating applications due to seal lip hydroplaning
	High load of helical wound spring improves sealability Preferred lip design for dynamic sealing of abrasive media Reduced probability of seal lip hydroplaning	Requires good lead-in chamfer if hardware is installed lip first Lip design must be used in combination with radius lip style