If you are using a packed pump, installing and adjusting it properly can be the difference between the pump succeeding or failing. If your pump has a lantern ring, make sure to remove both the ring and the packing beneath it. Also, make sure not to damage the shaft or the bore if you use a packing hook or a pick to remove your packing.
Inspect the Pump
Since you are sealing the moving surface, the condition of the sleeve or shaft is crucial. Pitting or axial scratches on the sleeve or shaft can cause damage to the sealing surface. You want the surface finish between 16 and 32 μin Ra. If there is too much wear, replace the sleeve or resurface the shaft.
Although the bore diameter surface doesn’t move, it is still necessary to seal it. Axial scratches can cause your pump to leak fluid. If you have a split case pump, there should be two seams running axially, with gaskets inside. If the gasket has receded too far into the seam, it can also cause a leak.
Measure and Record for Future Use
Dimensions such as stuffing box depth and diameter and also shaft diameter should be measured and recorded. In the case of flush injection, the location of the flush port and the length of the lantern ring should also be measured and recorded. These measurements help align the lantern ring properly with the flush port. If the pump has proven inconsistent in the past, this could be the solution you require.
Cut the packing into individual rings; make sure there is no gap between the ends when they are put into the stuffing box.
Each ring should be firmly seated into the bottom of the box before you install the next one. This creates more consistent compression throughout the packing. You can use short lengths of split tubing, metallic bushings or corrugated cardboard for tamping. Offset the seam of each successive ring by 90 degrees.
You want enough leakage to cool the seal and lubricate the pump but not enough to affect the integrity of the seal. Be sure not to overtighten and make sure your adjustments are in proportion with the leakage rate.
Call 1300 922 973 for more information.