Page 98 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Installation, Maintenance, and Repair of Emkal Pumps 83

be within .OOO5 in. per in. of stuffing box bore for pumps with me-
chanical seals and .001 in. per in. of stuffing box bore for packed
pumps. If the coupling has an adjusting plate such as the four-piece
coupling shown in Figure 2-1 1, it can be unscrewed until it engages
the driver half coupling or spacer to verify alignment between the
pump shaft and the driver shaft.
4. The driver bolts are then tightened and two dowels installed.
5. After the coupling is completely assembled, check the runout of the
pump shaft or shaft sleeve, measured by a dial indicator immedi-
ately above the stuffing box or mechanical seal. Paragraph 2.8.2.7
of Reference 1 requires that this runout not exceed .002 in. T.I.R.
for new pumps operating above 1400 rpm, or .004 in. T.I.R. for
new pumps operating below 1,400 rpm.

Maintenance and Repair of Driver Bearings

Except for drivers with grease lubricated ball bearings, dry sump oil
mist lubrication for driver antifriction bearings is recommended. Con-
current elimination of cooling water is generally feasible. If a self-con-
tained lube oil reservoir is required, lube oil purification is recom-
mended. These topics are detailed in Chapter 7 of Volume 1 of this series.
The precautions required for proper assembly and removal of ball bear-
ings are also covered in Chapter 7 of that volume.

Maintenance and Repair of Submersible Motom
Submersible pumping units are generally not pulled from the well until
the pump performance has deteriorated by about 5 percent head loss, or
the motor has burned out, or “megging” of the motor windings shows a
low resistance to ground. Repair of a damaged motor should only be
done by the manufacturer or by an authorized repair shop. Some manu-
facturers stock rebuilt motors for immediate shipment so that outage time
is minimized. Instructions for the preparation of used motors for ship-
ment must be followed with great care so that further damage is avoided.
Detailed information on the maintenance of a particular type of submers-
ible pumping unit is contained in Reference 2.

Maintenance and Repair of Driver to Pump Couplings
Two piece or three piece couplings are used to connect solid shaft driv-
ers to pumps with packed stuffing boxes and closed impellers. Three-
piece couplings have threaded adjusting plates for adjusting axial impel-
ler clearances in vertical pumps with semi-open impellers. Four piece