UNIREX Pump - page 43

MARK 3 USER INSTRUCTIONS ENGLISH 71569102 08-06
Page 43 of 68 flowserve.com
Lastly, uniformly tighten the set screws
[6570.3] in incremental steps up to the final torque
value to lock the bearing carrier in place.
Figure 6.6
Example: If a pump was to be placed in a service with
an operating temperature of 100 °C (212 °F) the
impeller setting would be 0.53 mm (0.021 in.) off the
rear cover plate. Since it is necessary to add 0.05 mm
(0.002 in.) for the movement caused by tightening the
set screws an adjustment of 0.58 mm (0.023 in.) is
needed. First turn the bearing carrier counter-clockwise
until the impeller comes into light rubbing contact with
the rear cover. To determine the number of indicator
patterns that you will need to rotate the carrier, divide
0.10 into the desired setting;
0.58 / 0.10 = 5.8 (0.023 / 0.004 = 5.8). Rotate the
bearing carrier clockwise 6 indicator patterns which
will give a clearance of 0.60 mm (0.024 in.).
Flowserve suggests that a felt tip pen be used to
mark an initial reference point on the bearing housing
and the bearing carrier as shown in figure 6-6.
Then make a second mark on the bearing carrier 6
indicator patterns counter-clockwise from the initial
reference point. Rotate the bearing carrier clockwise
until the second mark on the bearing carrier lines up
with the initial reference point mark on the bearing
housing. Lastly, uniformly tighten the set screws
[6570.3] in incremental steps up to the final torque
value to lock the bearing carrier in place.
6.6.2 Installation and clearance setting for front
vane open style impeller on Mark 3 Standard,
Unitized self-priming, Lo-Flo, and In-Line pumps
Like all front vane open style impellers, the Flowserve
open impeller clearance must be set off the casing.
The casing must be installed to accurately set the
impeller clearance. (Realizing that this can be very
difficult, Flowserve strongly promotes the use of
reverse vane impellers, which do not require the
presence of the casing to be properly set.)
Attach the power end/rear cover plate assembly to
the casing. Now set the impeller clearance by
loosening the set screws [6570.3] and rotating the
bearing carrier [3240] to obtain the proper clearance.
Turn the bearing carrier clockwise until the impeller
comes into light rubbing contact with the casing.
Rotating the shaft at the same time will accurately
determine this zero setting. Now, rotate the bearing
carrier counter-clockwise to get the proper clearance.
Refer to figure 5-12 for the proper impeller clearance.
Rotating the bearing carrier the width of one of the
indicator patterns cast into the bearing carrier moves the
impeller axially 0.1 mm (0.004 in.). (See figure 6-5.)
Determine how far to rotate the bearing carrier by
dividing the desired impeller clearance by 0.1 mm
(0.004 in.) (one indicator pattern). Tightening the set
screws [6570.3] will cause the impeller to move
0.05 mm (0.002 in.) away from the casing because of
the internal looseness in the bearing carrier threads.
This must be considered when setting the impeller
clearance. Rotate the bearing carrier counter-
clockwise the required amount to get the desired
clearance to the casing.
Lastly, uniformly tighten the set screws
[6570.3] in incremental steps up to the final torque
value to lock the bearing carrier in place.
See section 5.3 for impeller clearance settings.
Example: If a pump was to be placed in a service with
an operating temperature of 150 °C (302 °F) the
impeller setting would be 0.69 mm (0.027 in.) off the
casing. Since it is necessary to subtract 0.05 mm
(0.002 in.) for the movement caused by tightening the
set screws an adjustment of 0.64 mm (0.025 in.) is
needed. First, turn the bearing carrier clockwise until
the impeller comes into light rubbing contact with the
casing. To determine the number of indicator patterns
that you will need to rotate the carrier, divide 0.10 into
the desired setting;
0.64 / 0.10 = 6.4 (.025 / 0.004 = 6.3). Rotate the
bearing carrier counter-clockwise 6.5 indicator patterns
which will give a clearance of 0.65 mm (0.026 in.).
Flowserve suggests that a felt tip pen be used to mark
an initial reference point on the bearing housing and the
bearing carrier as shown in figure 6-6. Then make a
second mark on the bearing carrier 6.5 indicator
patterns clockwise from the initial reference point.
Rotate the bearing carrier counter-clockwise until the
second mark on the bearing carrier lines up with the
initial reference point mark on the bearing housing.
Lastly, uniformly tighten the set screws [6570.3] in
incremental steps up to the final torque value to lock the
bearing carrier in place. The impeller is now set for an
impeller setting of 0.7 mm (0.028 in.) off the casing.