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Alignment Check

Wolskis

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Prior to rechecking the rim and face to face the shaft was rotated 2 revolutions. We have a hot #2 bearing and trying to determine the cause and the first step is checking alignment. Looking at the "A" coupling between the HP and LP rotors of a steam turbine.

 

Wolskis

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lower half.jpg
Next the #2 bearing upper and lower halfs were rolled out. Here's the lower looking good.
 

wsuwrhr

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Kinda curious about your testing method as in exactly what you are checking for with a travel indicator.

Alignment shift between the couplers, or ...?

Won't gravity come into play here and give an erroneous reading?

Brian
 

Wolskis

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I'm thinking the diamond is for the measurement of the Babbitt temperature. A thermocouple will be inserted from the backside. The hole should be for the lift oil. This design calls for 3000psi oil to lift the shaft .004 while at slow speed. I'll look into further.
 

Wolskis

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Kinda curious about your testing method as in exactly what you are checking for with a travel indicator.
Kinda curious about your testing method as in exactly what you are checking for with a travel indicator.

Alignment shift between the couplers, or ...? Two measurements, face to face will look at the gap between the face of the coupling at 4 points, 0, 90, 180, 360 for a total of 16 times. Rim to rim will compare the height of one rim to the other again at the same 4 points. In between the lube oil and lift oil is turned on and the shaft is rotated 90 degrees, lift and lube oil shutoff and then wait several minutes for the shaft to settle. This can take about 45 minutes to complete one set of readings.

The steam turbine has 6 bearings, 3 shafts and 2 couplings. I'll see if I can post a pictorial of the expected alignment. It's not what you would expect.

Won't gravity come into play here and give an erroneous reading? To much mass involved. The shaft on the right weighs in at 50k and left at 115k.

Brian


Alignment shift between the couplers, or ...?

Won't gravity come into play here and give an erroneous reading?

Brian
 

Icky

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You know they make Lasers for that now, you can get rid of your dial indicators:D
 

Kaotic

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WOLSKIS, where do you work at? I manage the Gila Bend Power Station outside of Gila Bend, AZ. We have (4) GE steam turbines here and (8) frame gas turbines, 2,300 mw plant.
 

Wolskis

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You know they make Lasers for that now, you can get rid of your dial indicators:D
This is part of construction and startup and different craft at each site. The tools are stored in gang boxes and transported around the world where needed. The initial cost and potential for damage is too great of risk, thus the old school way.
 

Icky

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Kinda curious about your testing method as in exactly what you are checking for with a travel indicator.

Alignment shift between the couplers, or ...?

Won't gravity come into play here and give an erroneous reading?

Brian

Google reverse dial alignment
This is part of construction and startup and different craft at each site. The tools are stored in gang boxes and transported around the world where needed. The initial cost and potential for damage is too great of risk, thus the old school way.
I know, those things are like 30k +from what I hear, I haven't done reverse dial alignment since apprenticeship school.
 
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