UNIREX Pump User Manual

Page 43

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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.

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