The ROTALIGN ULTRA laser system with Continuous Sweep allows turbine coupling checks with two measurements to be completed in as little as 6 minutes instead of 6 hours. The time savings can be further increased by using multiple laser systems for each coupling and having them start at the same time.”

ENERGY-TECH • April 2013

A power turbine consists of multiple rotors that are joined by couplings.  A critical point in the service of a turbine is the coupling check.  This check determines the position of the two faces of the coupling with respect to each other.
A “16-point check” has been the standard measurement method for verifying this coupling alignment.  In its core form,  it is like the “rim and face” check used in standard dial indicator alignment.
The rim readings are measured by a dial indicator that indicates along the edge of the coupling. This reading verifies the offset at the center of the shafts at the coupling point (providing of course that the coupling hubs themselves are not out-of-round or eccentric to the shaft centerline.)…

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