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Pump Shaft Alignment Procedure - Vertical

  1. As with all vertical moves, using a dial indicator is not necessary to determine the change in the vertical direction, but it can be helpful to check for any soft foot created when moving the machine. 
  2. By using a micrometer, the exact thickness of the shims being installed can be determined for the required alignment correction. Be sure to measure every shim that is installed. Do not believe what is printed, stamped, or etched on the shim. Always check the shim to be sure. 
  3. When loosening the hold-down bolts, the first precaution is to loosen only two bolts at a time when making any shim change. If you loosen all the hold-down bolts at the same time and then raise the machine, the entire configuration at the feet may change. This is particularly true if any of the feet have been corrected for soft foot conditions using a tapered or step shim.
  4.  Leaving two hold-down bolts tight reduces the chances of an uncontrolled move. Any uncontrolled movement of the machine may change the horizontal, axial, and even the vertical positioning of the machine, thereby negating all your previous work. 
  5. Loosen the bolts on either the left or the right side of the machine, but not both sides. 
  6. Raise one side of the machine just enough to make the shim change. If the machine is raised too high, it can bend the feet on the side of the machine where the hold-down bolts are tight.
  7.  Make the necessary shim change and tighten down the bolts to their proper torque value. 
  8. Repeat the process for the other side of the machine. 
  9. Each tightening of any bolt on the machine should be treated as though it is the last time to work on that particular bolt.
  10.  For all vertical moves, be sure to raise the machine just enough to add or remove the desired amount of shims. Any excess movement of the machine in the vertical direction can result in a bent foot. 
  11. Once you have the machine raised enough to make the shim change, remove the shims from underneath each foot and add or subtract the amount of shims you have determined. 
  12. Always use the least number of shims under a foot as is practical. The more shims under a foot, the more likely a spring effect or soft foot is to occur. 
  13. If possible, make or use a single piece of shim the total thickness required under the foot. If this is not possible, a maximum of three to four shims should be the limit. This gives the foot a solid place to rest on and reduces the possibility of anything getting between individual shims. 
  14. When making shim changes for the vertical alignment, it is important to remember the shims must be placed beneath those shims that are present to correct for soft foot. If the shims used for correcting the vertical alignment are placed on top of the soft foot shims, it can create more soft foot problems. 
  15. When inserting the shims under the feet, insert the shims slot all the way in until the shim has "bottomed out" in the slot. You should then pull the shim back about a quarter of an inch before tightening the bolt. If you leave the shim inserted all the way into the threads, tightening the bolt will pinch the end of the shim and may affect the accuracy of the shim change. 
  16. After completing the shim changes and tightening the hold-down bolts, another set of readings should be taken. If the move is within the specified tolerance, proceed with the horizontal moves. If a second move is required, determine the necessary shim change and make the correction.


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