May 13, 2015
Understanding Alignment Target Data from the VibrAlign ThermAlign App
By Michael Keohane
Dynamic Movement, often thought of as thermal growth, is a hot topic among alignment professionals (I’ll be here all week!). Plant Services Magazine in conjunction with VibrAlign recently hosted a webinar on this subject (details below).
One of the more popular ways to compensate for thermal growth is through the use of a thermal growth calculator. The calculator calculates growth changes that occur from measured temperature changes on the machine. VibrAlign released a free app, ThermAlign, that performs the calculations from measured data.
Modern laser shaft alignment tools allow the user to input target values prior to doing the alignment. Growth is the actual movement due to temperature changes and targets are the compensation for that growth. The ThermAlign app takes the growth values and converts them to target values at the feet of the moveable machine. The target values can be input into the laser system prior to performing the alignment. Here is an example from real data taken in the field. In this example the customer took temperature readings on the blower at the feet and at the shaft centerline. The motor wasn’t measured since his experience proved the temperature changes were minimal.
To find out more about Thermal Growth and OL2R checkout the “On Demand” Webinar hosted by VibrAlign’s Stan Riddle and Mike Keohane, entitled “Hot Alignment & Thermal Growth.” The Webinar steps through 4 ways to deal with thermal growth target values when performing a shaft alignment!
1. Inputting thermal growth targets as provided by the engineering department,
2. Using a Hot Check to measure the thermal growth and set targets,
3. Using the free ThermAlign app to calculate the thermal growth targets, and finally
4. Measuring the thermal growth, as well as dynamic changes in machinery, using OL2R software and
fixtures. (OL2R, by the way, stands for Offline to Running)
To see the recorded “On Demand” version of the webinar please visit our sponsoring partner, Plant Services [HERE]. Click the “On Demand” tab and scroll to the bottom of the list of webinars and you will see “Hot Alignment & Thermal Growth.” Click Login. You will need to set up a login to view the webinar, which lasts about an hour including questions and answers.
Additional Blog Posts on the subject of dynamic movement.