We can provide our services to power plants worldwide

Bradenton, Florida

941 - 527 - 6196
941 - 755 - 5229 (FAX)

Milwaukee, Wisconsin

414 - 698 - 5644



Since most turbine-generator problems are present even prior to starting the unit, we know that almost any such problem can also be identified and fully prevented ahead of time during an outage if only a few steps of measurement and analysis are included into the outage scope.

The best outage result is when the responsibility to follow rotors through an outage is in a single set of hands, following, reviewing and assessing all processes from shutdown, to shop inspection, machining and balancing, as well as reviewing the turbine alignment prior to restart, and start up monitoring.

Typically in practice, the responsibilities within an outage are split between the disassembly maintenance group, the service shop, assembly maintenance groups (including alignment) and the plant operations group. Each group has their own standard practices (mostly following “general industry standards”) which are totally independent of each other. In this approach, each party can be “right” based on their industry standards and contractual requirements within their own field of responsibility, but if the end result is a machine needing additional correction after startup, then it becomes “nobody’s” fault, and the responsibility and cost to make it right falls on the plant.

The issue in assuring good outage outcomes is not necessarily whether a certain service shop or group is properly following standard industry practices (of course, they must as a minimum), but to examine the assumptions behind the standard practices and address all areas that allow problems to still slip through.

The standard industry practices of inspection, machining, assembly and alignment have been developed and streamlined by OEMs, and are applicable to newly manufactured rotors with all dimensional specs within ISO 1940 tolerances. These standard practices contain the assumption that rotors are within such specifications, individually or in an assembly, in order to expect a properly running machine. However, these “standard practices” in the service industry can fall short for rotors with eccentricities outside such specifications, and by design do not catch the errors that cause true dynamic problems, because they are assumed not to exist or are fully unrecognized by “traditional” rotordynamics theory and practice.

This situation can only be overcome with a unified diagnostic approach that considers the combination and sum effect of all parties’ work, standards and tolerances, connected with in-depth rotordynamics analysis (beyond simply resonances and balancing) requiring full understanding of the real life kinetics of rigid bodies under the influence of torque and inertia.

If rotor oversight through an outage is performed by Z-R Consulting's approach , there will be no need for "field balancing" after an outage, and the unit can be returned to service without delay. And this is the ultimate benefit and goal that we believe any plant is expecting.