Our ERAG: The Concentricity Alignment Tool

"Micro" CAT head, "Small" CAT head, and "Large" CAT head.

µCAT, SCAT, and LCAT measuring heads

If you really want to significantly reduce your repair outage time, our Concentricity Alignment Tool (CAT) is exactly what you need. Often referred to as an Electronic Radial Alignment Gauge (ERAG), we are the exclusive manufacturer of these tools.

  • Does away with tightwire and/or laser alignment
  • Directly measures the amount of diaphragm misalignment with the rotor in place
  • Factory and field-tested method of diaphragm alignment since 1992
  • Alignment method proven thru thousands of hours of use
  • Depending on the turbine, adjustments can be made and final measurements taken, without having to remove the rotor
  • Cost effective — often pays for itself in one outage
  • Easy to use — direct numeric readout
  • Accommodates a wide range of turbine sizes
  • Very accurate (resolution to 0.0001 inch, accuracy of ±0.001 inch maximum)
  • Durable — units rarely require maintenance even after years of service
  • Parts are readily obtained from the factory and are usually field replaceable
  • See how to use the CAT tool

Inserted into the empty packing groove, the Concentricity Alignment Tool (CAT) allows annular space variations to be displayed on a LCD display as it is pulled through the packing groove as shown. The head “rub bars” ride on the turbine shaft and the head lever arm rides on the ID of the diaphragm. As the head is pulled through the packing groove, the lever arm follows the contour of the diaphragm ID and the dimensional variation is displayed. See the complete operating instructions and specifications on the CAT along with other EDS products under the “Turbine Tools” heading.