This allows for adjustments that will be required during final alignment. Bring the piping to the pump, but do not connect yet, as shown in Figures 10 and 11. Final Alignment Take final measurements, tack weld the spools in place, and finalize all welding once you are satisfied with the rough alignment achieved so far. Leave a square and parallel gap between the flange faces. As the piping is tightened into place, the shaft should not move more than 0.002 .
Several clues are common to piping misalignment.
These include leaky mechanical seals, hot running bearings and failures. A quick analysis of failed parts can clearly show the evidence of piping misalignment. To make a final confirmation of the symptoms, unbolt the piping while measuring the movement in the vertical and horizontal planes. See Figure 13 for indicator placement. Place the indicator in horizontal and vertical planes, using the motor and pump coupling halves.