AccuSeal - Friction Considerations

Friction Considerations

The amount of friction induced by a seal depends on several different factors including: seal material, spring load, system pressure and temperature. To provide the best sealing solution for a given application, the most critical aspect of the system must be determined. If positive sealing is most important, then a higher amount of friction and wear must be acceptable. If seal life and low friction are critical, then absolute sealability may be reduced. Seal wear in dynamic systems is unavoidable. Careful consideration of friction issues can help maximize seal performance. An intelligent material selection and proper hardware preparation can provide an ideal solution to almost any problem. The total force to overcome friction in a system is dependent on several factors.

Coefficient of friction of the seal material.

Spring force

System pressure force

Dynamic surface finish

Diameter of dynamic surface

To calculate the breakout force for a given system, follow the steps and use charts 1.5 & 1.6.

1.5

1.6

¹Charts based on ľ=0.10. Seal running on dry steel surface with an 8ľin Ra finish. Medium spring load.

Determine the applicable spring type chart.(i.e. Offset Coil or Cantilever)
Find the appropriate system pressure on the x-axis.
Trace vertically to the intersection point of the appropriate spring series listed to the right of the chart.
From that point, trace left horizontally back to the y-axis. This is the correct force factor.
To find the breakout force, multiply the force factor by the dynamic surface diameter. This will give the breakout force in (lbs.) ¹

* Torque (T) in-lb = Force (F) lb x Dynamic Radius (R) in. Consult the factory for conditions not shown.

Introduction

Spring
Energizers

Jacket
Materials

Hardware Prep

Friction
Considerations

Load vs
Deflection

Gland
Considerations

Temp vs
Pressure

Special
Configurations