EDS Measurement Systems, Inc.

Tag: ERAG

  • The Concentricity Alignment Tool ERAG

    The Concentricity Alignment Tool ERAG

    When your turbine needs maintenance, our Concentricity Alignment Tool (CAT) is exactly what you need. It significantly reduces your repair outage time since you do not remove the rotor to perform a realignment. Often referred to as an Electronic Radial Alignment Gauge (ERAG), we are the exclusive manufacturer of these tools.

    Our ERAG Features

    • Replaces tightwire and 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 a single outage
    • Easy to use — direct numeric readout in mils (0.001 inch)
    • 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 wearable parts are field replaceable
    • See how to use the CAT tool

    Basics of Operation

    Inserted into the empty packing groove, the Concentricity Alignment Tool (CAT) allows annular space variations to be measured live on a display as it is pulled through the packing groove. The head “rub bars” ride on the turbine shaft and the head lever arm rides on the inner diameter of the diaphragm. As the head is pulled through the packing groove, the lever arm follows the contour of the diaphragm I.D. and the dimensional variation is displayed.

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  • µCAT Measuring Head for Low Radial Clearance

    µCAT Measuring Head for Low Radial Clearance

    While our SCAT and LCAT measuring heads can be used with a wide range of turbine brush-seal grooves, the latest µCAT (“mu-CAT” or “micro CAT”) fits where the others can’t. The latest turbines for power generation being developed include stages with very small radial clearance.

    Low Radial Clearance

    While our prior µCAT was the same width as the SCAT (0.500″), the new version is only 0.300″ wide to fit narrow brush-seal grooves, and like the older model, can measure radial clearances from 0.200″ to 0.250″. An adjustable “hat” can be installed on top to fit 0.300″ to 0.363″ brush-seal grooves, and SCAT shims and spacers can be installed to fit spacings 0.363″ to 0.500″ wide, at which point the SCAT head can be used.

    Please contact us for information about purchase or rental of this new tool.

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  • Using the Concentricity Alignment Tool

    Here are the basic steps to use the Concentricity Alignment Tool (CAT) in almost any turbine.

    Step #1

    Thread Tape
    Insert tape measure into empty packing groove until it exits from the packing groove on the opposite side of the shaft.

    Step #2

    Attach Tape
    Attach the head to the end of the tape using the tape clip with the wire retainer to secure the end of the tape to the head.

    Step #3

    SCAT at 9:00
    Insert the head into the packing slot by depressing the lever arm.

    Step #4

    SCAT at 3:00 position00.0 meter
    Pull the head to the 3:00 o’clock position using the tape measure and then “zero” the meter using the coarse adjustment on the head and the fine adjustment on the power supply.

    Step #5

    SCAT at 6:00 position-10.4 meter
    Pull the head to the 6:00 o’clock position using the cable and take the reading.

    Step #6

    SCAT at 9:00-19.9 meter
    Pull the head to the 9:00 o’clock position and take the reading.

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