In most applications, the V-seal rotates with the shaft to provide a slinging action. As such, it is subject to centrifugal force. At speeds below 1600 surface feet per minute (FPM), the stretch tension of the V-seal is sufficient to hold it onto the shaft.
*Above 1600 FPM, axial back up is required in the form of a step in the shaft or a snap-ring or lock collar.
Above 2400 FPM, radial back up is required in the form of a mounting pocket or clamp or clamp around the V-seal body. Above 3000 FPM, the lip of the V-seal lifts away from the counterface resulting in a clearance seal and eliminating drag and wear. The V-seal can also be mounted stationary and run against a rotating counterface. In this case, centrifugal force has no effect on the V-seal.
* The V-seal should always have axial back up in oil applications.
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