Service manual

7
The objective of any aligning procedure is to align shafts (not align coupling hubs) by
using methods that cancel out any surface irregularities, shaft-end float, and
eccentricity. At operating temperatures above 175
o
F (65
o
C), pumps require “hot
alignment” after pump and driver reach normal operating temperatures. Also, re-check
final alignment after all piping is connected to pump.
D.6.2 Flexible Shaft Couplings
Flexible couplings are intended to provide a mechanically flexible connection for two
aligned shaft-ends. Flexible couplings are not intended to compensate for major
angular or parallel shaft misalignment. The allowable misalignment varies with the type
of coupling. Any improvement in alignment beyond coupling manufacturer’s minimum
specification will extend pump, mechanical seal or packing, coupling, and driver service
life by reducing bearing loads and wear.
CAUTION ATTENTION
• Flexible couplings are NOT intended to permit significant shaft misalignment. Proper
alignment must be established/maintained to obtain proper operation and maximum life.
• Pump alignment requirements are nearly always more strict than coupling alignment
requirements. Regardless of coupling manufacturer’s stated limits, pump-to-driver shaft
alignment must be per pump’s alignment requirement.
• Be sure all coupling set-screws and bolts are tight and coupling gap is properly set.
D.6.3 Aligning Foot Mounted Pumps - See Figure 3
Feet
Figure 3 – Foot Mounted Pump
To install foot mounted pumps, perform the following:
• Install pump and driver onto baseplate after installing appropriate coupling halves on
pump and driver shafts.
• Perform alignment of pump and driver shafts using dial indicators. Acceptable
alignment has been attained when FIM (Full Indicator Movement) is less than or equal
to 0.005 inch (0.13 mm) for face (angularity) and rim (parallelism) readings at or near
coupling outer diameter while rotating both shafts together one full turn (360°). See
Figure 4.