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II-C. Leveling and Grouting of
Baseplate Initial Alignment Check
1. Put the unit in place on wedges located at four points as
shown in Fig. 2. Some long installations may require additional
wedges near center of bedplate.
2. Adjust wedges to level unit (approximately), placing unit
between ” and 1” above foundation. Level or plumb suction
and discharge flanges. Then, bring the coupling halves into
reasonable alignment by adjusting the wedges as needed.
3. Make sure that the baseplate is not distorted and that final
accurate coupling alignment can be established within the limits
of movement of motor and by shimming motor if necessary.
4. Tighten foundation bolts finger tight. Build dam around
foundation and pour grout. Fill to level of grout hole making
sure that the areas under the pump and motor feet are filled
solid. Allow grout to harden at least 48 hours before further
tightening foundation bolts. Tighten pump hold down bolts.
II-D. Piping Practices
Guidelines for piping are given in the “Hydraulic Institute
Standards” and should be reviewed prior to pump installation.
All piping should be supported independently of, and line up
naturally with, the pump flanges. NEVER DRAW PIPING
INTO PLACE BY USE OF FORCE AT THE FLANGED
CONNECTIONS OF THE PUMP.
Both suction and discharge piping should be as short and direct
as possible to minimize friction losses. Foundation, pump and
driver hold–down bolts should be tightened prior to connecting
suction or discharge piping to the pump.
On units handling corrosives, the piping can be arranged to
allow flushing of the pump prior to opening of the unit for
servicing. After connecting suction and discharge piping to the
pump, rotate pump by hand to be sure that there is no binding.
II-E. Alignment—Preliminary
Alignment of the pump and driver is of extreme importance
for trouble–free mechanical operation. Alignment should be
obtained by adding or removing shims from under the motor
feet. The pump bearing frame foot should never be adjusted
to obtain alignment. The proper shimming is installed under
the bearing frame foot at the factory on units shipped with
bedplates. Changing the pump casing or bearing frame in the
field will require a reshimming of the frame foot. The proper
number of shims is installed when the pump shaft is level and
parallel to the bedplate surface. Proper shimming is achieved
by loosening frame foot and tightening casing foot. This should
create a gap between the frame foot and bedplate between 0
and .040 inches (1mm). This must be filled with shims and
the frame foot retightened. If this procedure is not followed,
mechanical problems can result. The final alignment is done
after the unit has been run under actual operating conditions.
The following are suggested steps for aligning the unit, prior to
initial startup.
1. Parallel Alignment: The unit is in parallel misalignment
when the shaft axes are parallel, but not concentric. During
initial alignment, vertical parallel alignment may be different,
due to thermal expansion of the unit at actual operating
conditions. The following is a suggested cold setting for motor
driven units:
Pumpage
Temperature
Above Ambient Set Motor Shaft
Ambient .002–.004” low (.05–.10 mm)
100° F. .000–.002” high (.00–.05 mm)
200° F. .004–.006” high (.10–.15 mm)
300° F. .008–.010” high (.20–.25 mm)
400° F. .012–.014” high (.30–.35 mm)
500° F. .016–.018” high (.40–.45 mm)
2. To check the parallel alignment of “spider–insert” couplings,
place a straight edge across both hubs at four points, 90° apart
(see Fig. 3). To check the parallel alignment of flexible spacer
couplings, place a dial indicator on one hub and rotate that
hub 360° while taking readings on the outside diameter of the
other hub. Alignment occurs when indicator deflection does
not exceed .002” T.l.R. (see Fig. 4) of the recommended cold
setting in elevation and not more than .002” T.l.R. side to side.
To check angular alignment of a “spider–insert” coupling, use
calipers at 90° intervals on the circumference on the outer end
of hubs. When caliper measurements are identical, the unit is
in angular alignment. The correct gap between the hub and
insert will be given in the coupling manufacturer’s instructions
supplied for the pump.
To check angular alignment of flexible spacer couplings, place
a dial indicator on one shaft hub and rotate the hub 360°. Take
readings from the face of the other hub. Alignment is achieved
when deflection does not exceed .002” (see Fig. 5).
Figure 2
WEDGES