Installation and Maintenance

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Q. The coupling’s flexible elements have axial capability. Why do I need shims?
A. The coupling’s flexibility should not be used for axial adjustability. High performance couplings are supplied with shim sets to accommodate errors in length at installation. Couplings under 6 inches (152 mm) in diameter generally have +.062 inches  (+1.58 mm), while couplings over 6 inches (152 mm) have +0.125inches (+3.2 mm). Shims should be shared equally between ends so the integrity of the flange pilots is maintained.
 
Q. Why are shims required on flexible element - disc and diaphragm - high performance couplings?
A. Unlike gear tooth couplings, which have a clearance, fit between the mating teeth that allows for axial movement, flexible element couplings depend on the stretching and bending of spring-like material to accommodate axial movements between equipment shafts. These movements need to be considered when the coupling is installed.

Usually the measured field shaft separation is a little different than that for which the coupling was designed. Shims are provided for adjustment, generally at the spacer flanges, to make sure the coupling will not be over-stretched due to this difference.

One reason for a difference between actual and design shaft separations are machinery installation tolerances. Another is the tapered shaft hub fit-up tolerance.
 
Q. What tools do I need when installing a high performance coupling?
A. Tools necessary for the installation include: mounting (hydraulic) tooling, wrench set, torque wrench capable of meeting the bolt tightening torque values, micrometers for measuring distance between shaft ends, O.E. M. instructions, and the coupling drawing. Kop-Flex has an installation training tape for high performance couplings, available upon request.
 
Q. What is the recommended inspection interval for high performance couplings?

A.

 High performance gear tooth couplings should be inspected, cleaned and repacked with grease every 12 to 18 months. Disc and diaphragm, non-lubricated, couplings are expected to operate continuously without interruption for a minimum of five years. Visual inspection of metallic membrane couplings is generally all that is required.