Operation Manual
9.6 Setting the rotor clearances
Incorrect setting of the rotor
clearances will damage the pump.
1.
Fit the rotorcase (11) and retain with four
nuts (5) tightened to 30 lbft.
2.
Fit the setting ring (35) with chamfer towards
the shaft shoulder and 0.020 inch of shims
onto the shaft. At this point, do not fit 'O'
rings (45). Slide shaft sleeve onto the shaft
ensuring that the drivepin locates in any
position other than the missing spline.
3.
Fit the rotors (13) and torque the retaining
nuts (9) to 110 lbft.
4. Using a micrometer and feeler gauges
measure the front and back clearances
respectively.
5.
Adjust the shims (25) if necessary to ensure
the front and back clearances are within
the specified limits.
6.
Check the radial clearances are within
specification limits.
7.
If all clearances are correct, remove rotors,
shaft sleeves and rotorcase taking
care not to disturbe the shims.
8.
Lightly grease the seal sleeve 'O' rings (45)
and fit to the sleeve.
9. Fit the sleeves onto the shafts ensuring that
the drive pins locate in any other position
than the missing spline.
10. Fit the seal sleeve retaining clips (64) onto
the shafts.
11. Fit the rotorcase (11) and retain with four
nuts (5) tightened to 30 lbft.
9.7 Fitting the seal
O'ring - Refer to section
10
Mechanical Seal - Refer to section
11
9.8 Fitting the rotors
1.
Align the rotor with the missing spline of
the shaft.
2.
Lubricate the rotor nut sealing 'O' (10)
ring and fit to the nut groove.
3.
Use a plastic block between the rotors to
stop them turning while tightening the
rotor nuts (9) to 110 lbft.
4.
To check that the rotors are correctly
synchronised turn the pump by hand, and
check the meshing clearances with feeler
gauges through all six points.
9.9 Fitting the front cover
1.
Fit the front cover 'O' ring (7).
2.
Fit the cover (6) onto the rotorcase studs
(4) and tighten the front cover nuts to the
recommended torque - 30 lbft. Fit 'R' clips
(2).
3.
The pump can now be mounted with its
drive unit.
4.
Prior to start up the pump must be
filled with oil.
Read the start-up check list before
proceeding to start the pump,
see section 6.1
STP125 Page 22
