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RD EngiSeal


kc seals reciprocating


kc seals static



pressure low

Low Pressure
High Speed


kc seals single

kc seals double



The EngiSeal is KC Seals version of spring loaded u-cups, which are sealing elements that combine high performance polymer "seal jackets" with recent advances in spring technology as "jacket energizers". This unique combination of matching suitable materials for the seal and the spring allows our customers to seal under some of the most extreme service conditions, such as high temperature environments, the presence of harsh chemicals, or the need for a very low friction solution. The EngiSeal® product line is available to fit all standard hardware glands, though can also be designed to match any non-standard housings.

The EngiSeals sealing geometry can be modified to alter sealing performance. Please speak to one of our technical sales staff for more information This email address is being protected from spambots. You need JavaScript enabled to view it.

  • Low coefficients of friction
  • Maintains high performance over very long sealing life
  • Can handle rapid changes in temperature
  • High temperature range
  • Can be incorporated into new tool design to customer specification
  • Stick-slip-free operating for precise control
  • Wiping action from multiple lips design.
  • Valves
  • Pumps
  • MWD equipment
  • Gear drives
  • Separators
  • Actuators
  • Rotary applications
Technical Data


Unfilled PTFE

Material Code:


Molyglass filled PTFE


Bronze filled PTFE


Carbon graphite filled PTFE




Note: Alternative materials are available upon request


-200°C to +260°C
-328°F to +500°F


25 ft/s


5,000 psi


Chemical compatibility chart

Note: All parameters can vary depending on the specific application, please take the above information as a general guideline. Should you have any concerns please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.

Type Temperature Chemical Compatibility Wear Resistance Features
Unfilled PTFE (1001)

 -200°C to +260°C

-328°F to +500°F



Excellent insulating capacity. High dielectric properties. Low coefficient of friction, suitable for non-stick applications. Not recommended for dynamic applications, such as loaded sleeve bearings.

Carbon Graphite Filled PTFE (1020)

-200°C to +260°C

-328°F to +500°F



Chemical resistance in corrosive environments. Good initial wear and rubbing or sliding characteristics in both wet and dry applications. Excellent for piston rings (cylinder wear is reduced because the relatively soft CFPT surfaces entrap potentially abrasive foreign particles).

Bronze Filled PTFE (1023)

-200°C to +260°C

-328°F to +500°F



High thermal conductivity, with heat dissipation more rapid than in unfilled PTFE. Exhibits excellent tribiological properties in high speed dynamic applications. 


-200°C to +260°C

-328°F to +500°F



Designed for demanding sealing and wear applications, our proprietary 1130 blend has excellent tensile strength and elongation properties, as well as low friction.

Molyglass Filled PTFE

-200°C to +260°C

-328°F to +500°F



Long, steady-state wear life on hardened dynamic surfaces due to a low starting coefficient of friction. Excellent for extreme high pressure and temperature conditions.

Spring Energizers

Three different spring types may be chosen in the design of an EngiSeal®. Each type displays different capacities in load curve, unit loading and deflection range. These are canted coiled springs, helical springs and V-springs.

rd engiseal canted

Canted coiled springs: Code SPR-C

Produces a very flat load curve when compressed. Providing constant, predictable loads throughout a very wide deflection range, canted coiled springs are used to energize U-cup seals and other components. 

rd engiseal helical

Helical springs: Code SPR-H

Produces a very high unit load over a narrow deflection range. Constructed from flat ribbon stainless steel and other alloys wound into a helical form with a round cross section, helical springs are used in U-Cup seals and other components. 

rd engiseal vsprings

V-Springs: Code SPR-V

V-Shape geometry produces a moderate load over a wide deflection range. The stainless steel (or other alloy) cantilever design of a V-spring is applied as a radial or compression energizer inside a U-cup seal and other components. 

Please contact KC Seals (This email address is being protected from spambots. You need JavaScript enabled to view it.) for information regarding load and deflection.

Style Part # Rod Diameter B Housing Diameter A Groove Width D
RD 0.375 0.562 0.141
RD 0.500 0.687 0.141
RD 0.625 0.875 0.188
RD 0.750 1.000 0.188
RD 0.875 1.125 0.188
RD 1.000 1.250 0.188
RD 1.250 1.500 0.188
RD 1.500 1.875 0.281
RD 1.750 2.125 0.281
RD 2.000 2.375 0.281
RD 2.250 2.625 0.281
RD 2.500 2.875 0.281
RD 2.750 3.125 0.281
RD 3.000 3.375 0.281
RD 3.500 3.875 0.281
RD 4.000 4.375 0.281
RD 4.500 4.875 0.281
RD 5.000 5.500 0.375
RD 5.500 6.000 0.375
RD 6.000 6.500 0.375
RD 6.500 7.000 0.375
RD 7.000 7.500 0.375
RD 7.500 8.000 0.375
RD 8.000 8.500 0.375
Style Part # Rod Diameter B Housing Diameter A Groove Width D