1-10 Validity Rule

When aligning rotating machinery it is imperative that you obtain accurate shaft positional measurements. It is very easy and very common to make mistakes when taking these measurements so this tutorial will illustrate what you have to be aware of when taking your alignment readings to insure that the measurements you obtain are accurate and repeatable. There is a mathematical pattern that occurs when taking readings at 90 degree intervals around a shaft. This pattern is called the Validity Rule. The Validity Rule will confirm that your measurements make sense but more importantly, can derive a missing measurement if you cannot rotate all the way around the shaft.

[@ScottTurnerformeindustrious]

Top notch training. Thank you!

[@JaykeSapalaran-iq3qs]

Great video information 👍 thanks for sharing your knowledge and experience 🇵🇭🫡

[@dennisminks8282]

If the coupling face has 6 bolt holes, place one hole at 12:00, insert a bolt at the 1:30, 10:30 and 7:30 positions. The bolt should have a nut on the backside of the face lightly tightened so the head of the bolt may be turned by hand. An electrician's level can be mounted to the two bolts at the 1:30 & 10:30 positions and the leveled. The hole that was placed near the 12:00 position should now be within a couple of degrees for zeroing. Likewise, when you need the left/right positions, you use the same procedure for locating those points using the 10:30/7:30 bolts.

[@shaftalignment6105]

Great suggestion Dennis. Thank you for your input. John Piotrowski

[@vaibhavkambli1769]

Thanks sir for detailed information.

[@tomconner5067]

A degree wheel or increments on the outside edge of the flange/disc diameter would be ideal, and so would a tangential alignment dowel/rod tube on the fixed machine positioned to perform alignment measurements on the adjustable machines rotating shaft and or flange/disc outside diameter which should have incremental 360° markings stepping up increasing at every 5° 10° dot point at every 30° (except @ 0-360°,120°,240°) 45° maximum size at every 90° only diamonds at 0-360° 120° 240° all you need to know is the center and constant radius or diameter

[@shaftalignment6105]

Great suggestion Tom. Thank you for your input. John Piotrowski

[@jonathanponce5228]

Please ad more sample laser alignment how to align and add simming or minus

[@Quy_Tran64]

hi. why when measuring 2 sides we have negative results .but not 1 side negative , 1 side positive . please explain . thanks

[@cesarmaravi7915]

Great video, thanks!

[@bossjerometechshow]

Pls sir add in our topic reversed alignment method

[@hadidtedji6389]

thank you its very helpful

[@amirzayd2805]

Engineer John, I have question.
For the validity rule
(Top + Bottom) = (South + North)
Using clock symbol
(12:00 + 06:00) = (03:00 + 09:00)
This rule is applicable on Rim Only or Radial readings?
How about the Face Readings or Axial, Same or different?
Kindly enlightenment me.
Thanks 👍

[@shaftalignment6105]

Amir: The Validity Rule applies to either radial / rim OR face / axial measurements.

[@amirzayd2805]

Thanks very much Engineer/ Sir John 👍

[@siddharthnizama8343]

Hi

[@tvrteja8837]

Thank you very much for the detailed explanation
Wow no Dislikes

[@shaftalignment6105]

Ravi - Thank you for your kind words. - John Piotrowski

[@kelliestratton6991]

Thank you

[@samyhassen1314]

excellent

[@bikramjitmandal4189]

Excellent excellent excellent
👍👌✌️👌👍✌️👍👌👉👉👉👉

[@shaftalignment6105]

Bikramjit: Thank you for your kind words. They are appreciated. Here is hoping this information will help you. John Piotrowski

[@hanmantnaronabhusnoor6298]

very nice important

[@khileshkumar838]

Thanks

[@ayeminnyein1222]

Thank sir

[@donignasis8355]

Thanks Sir JHON

[@shaftalignment6105]

Don: Thank you for watching. I hope this (and the other) tutorials are helpful. John Piotrowski