Dismantling the Pump Head
Rotors
1. Ensure isolating valve to the pump are closed.
2. Unscrew the front cover dome nuts. Carefully remove the cover as some residual
pressure may still exist in the system.
Front cover
3. If the cover is stuck, simply loosen using a soft mallet aimed at the sides, where the
cover overlaps the rotor case profile.
DO NOT LEVER OFF!
4. To aid further maintenance, it is advisable that the pump head is flushed out.
5. The pump is fitted with handed nuts. The top shaft has a left hand threaded nut,
and should be turned clockwise to remove it. The bottom shaft has a standard right
hand threaded nut. With the front cover removed, insert a wooden wedge to
prevent rotor rotation, while slackening off the rotor nuts for removal.
6. Before removing rotors, mark their positions relative to the shaft. Both rotors should
now be extracted by gently sliding them off their shaft splines.
7. Stubborn rotors may be released by removing the rotorcase nuts and lightly tapping
the rotorcase forward. DO NOT PRISE the rotors from behind.
NOTE: For routine maintenance it may not be necessary to remove the rotorcase. If
so, the rotors, rotorcase and o-rings mays now be inspected for wear and
damage. Refer to ROTOR ASSEMBLY for assembly of the pump.
Rotorcase
1. Disconnect pipe connections from the rotorcase.
2. Undo rotorcase nuts and remove rotorcase squarely from the locating dowels. Care
must be taken in supporting the rotorcase upon its removal, so as not to damage the
seals.
3. Special shaped shims will be found between the rotorcase and the gearcase.
These are used to determine the rotor clearances for a particular duty. Ensure shims
are marked for replacement in the same order on re-assembly.
4. It is now possible to remove the seals. One half of the seal will be in the rotorcase
and the other half on the shaft. These should be carefully removed and inspected
for wear or damage.
Page 6
To Next Page
Loading...