Flowserve Mark 3 Sealed Metallic Durco - Manual (Page 47)

MARK 3 USER INSTRUCTIONS ENGLISH 71569102 01-13
Page 47 of 72 flowserve.com
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) th e
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.
The above procedure is fairly straightforward when
doing the final setting of the impeller. However it can
be quite laborious when doing the preliminary setting
in order to establish the location of the mechanical
seal. For this reason, the following practice is
recommended. Before the pump is taken out of
service, adjust the impeller until it touches the casing
and then rotate the bearing carrier until the desired
impeller clearance is obtained. Identify this location
on the bearing carrier and then rotate the bearing
carrier until the impeller contacts the rear cover.
Record the distance from the desired impeller
clearance setting to when the impeller contacts the
rear cover. The pump is now removed from the
casing and taken to the shop for maintenance. When
it is time to set the seal, the impeller is simply set off
the rear cover by the same distance recorded earlier.
The above technique is only applicable if all
of the original pump components are reinstalled. If
the casing, cover, impeller or shaft is replaced this
method must not be used.
6.6.3 Installation and clearance setting for
Sealmatic pumps.
Install the repeller [2000.1] and covers [1220 and
1220.1] as described in section 6.9.3. Install a seal
guide from the Mark 3 tool kit to hold the repeller in
place. Set the repeller 0.38 to 0.51 mm (0.015 to
0.020 in.) off the cover following the instruction above
in section 6.6.1. Uniformly tighten the set screws
[6570.3] in incremental steps up to the final torque
value to lock the bearing carrier in place. Remove the
seal guide and install the impeller. Check the impeller
setting with a feeler gage. The gap should be 0.38 to
0.51 mm (0.015 to 0.020 in.). If the gap is outside of
the correct setting, it may be readjusted to get the
beat gap at the repeller and impeller.
6.7 Disassembly
6.7.1 Power end removal
a) Before performing any maintenance, disconnect the
driver from its power supply and lock it off line.
Lock out power to driver to prevent
personal injury.
b) Close the discharge and suction valves, and
drain all liquid from the pump.
c) Close all valves on auxiliary equipment and
piping, then disconnect all auxiliary piping.
d) Decontaminate the pump as necessary.
If Flowserve Mark 3 pumps
contain dangerous chemicals, it is important to
follow plant safety guidelines to avoid personal
injury or death.