Turbomachinery Coupling Catalog - Emerson Industrial Automation

Installation
Class AC couplings are commonly used in turbine-driven equipment where thermal growth and
distortion are substantial. Under these operating conditions, thermal growth must be identified
and compensated for accordingly.
After installation and cold alignment, the equipment should be run and brought up to operating
temperature. The alignment should then be checked in the hot condition using the hub sections
that project beyond the sleeve end ring as reference points. This operation can be accomplished
without disassembling the coupling.
High Performance gear couplings require lubrication, either continuous or batch. Continuous
lubricated couplings require a clean, filtered oil supply and a coupling guard complete with oil
supply and drain lines. Batch lubricated couplings can be used for low or moderate speeds where the
coupling can be packed with KHP grease at installation. All lubricated couplings require maintenance
attention to prevent contamination and sludge accumulation, which can reduce coupling life or
degrade the coupled machine performance.
The Series AC coupling is dynamically balanced and must be assembled with parts in the same
relative position as when balanced by the factory. Match marks are scribed on all parts to permit
proper assembly and reassembly. Bolts and nuts are individually weight balanced, which allows the
interchanging of any bolt with any nut.
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