Home
Contact Us
 

Other Links

 
    




Content

            1. Spring Energized U-Cup Description
            2. Spring Energized U-Cup Design
                        1. Dynamic Lip Configuration
                        2. Static Lip Configuration
                        3. Jacket Material
                        4. Spring Design
                        5. Spring Material
 




Description

Spring energized U-cups are engineered plastic seals, which incorporates a metallic spring into its design. The spring loads the seal lips against the mating hardware. This creates 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-Cup Design

Hi-Tech Seals recommends that clients contact one of our representatives when designing a new application.

Download a Seal Application Data Sheet to assist with communicating application needs

1. Select a dynamic lip configuration that suits your needs:

 Seal Type        Advantages        Disadvantages
  • Low wear rate
  • Preferred design for oscillatory and 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
  • May weep 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

2. Determine if the same sealing lip is appropriate for the static lip. Spring energized U-cups do not need to be symmetrical.

3. Identify which jacket material is required.

Variables to consider include temperature, chemical, pressure, velocity, and cost.

 Jacket Material*:
Temp. Range
 Virgin PTFE
-268°C
to
232°C
 Carbon/Graphite filled PTFE
-268°C
to
288°C
 Glass, Moly filled PTFE
-268°C
to
288°C
 Bronze filled PTFE
-268°C
to
288°C
 PEEK
-73°C
to
260°C
 Nylon
-54°C
to
121°C
 UHMWPE
-250°C
to
80°C


4. Select a Spring Design

Our in-house manufacturing typically uses cantilever springs. Helical and slanted coil springs are available upon request. Additionally, Hi-Tech Seals provides welded springs upon request.


Cantilever Spring (Finger Spring)

A cantilever spring is recommended for dynamic, medium load applications where low friction is desired. The V-shape spring provides constant compression load and is further energized by system pressure.

Helical Spring

A helical wound spring is made from a metal ribbon, which is coiled into a helix. The spring compresses radially producing a very high load versus deflection. The helical wound spring is preferred for static applications or applications where sealability is more of a concern than friction.

Slanted Coil Spring

A slanted coil spring, also known as a canted coil spring, is manufactured from a round wire that is coiled and angled. The process creates a compression force in the radial direction. The canted coil design is suited for dynamic applications where low friction is critical.
Go to our U-cup spring dimension charts.



5. Select a Spring Material

Most springs are composed of stainless steel; however, Hastelloy®, Inconel, and Elgiloy® are used in applications that require additional corrosion resistance.