Dismantling Of The Pump Body; Repair; Impeller Wear Ring Clearance; Clearance Of The Balancing Drum - Xylem Goulds MPE Series Mounting And Repair Instruction

Mounting Instructions MPE

2.5 Dismantling of the pump body

See the "Appendix" for relevant sectional drawing.
If the whole pump is to dismantle for maintenance work, the pump should be placed in vertical position (intake
pipe facing upwards). A workbench with a hole (approx. 10 mm larger than the shaft) is very helpful in such
cases.
The pump can stand on the coupling guard adapter (95).
A lifting tool is absolutely required for this work.
Secure the pump so that it cannot fall over.
Dismantling

Dismantle the pump according chapter 2.1 and 2.2 (dismantling the bearings), as well as chapter 2.3
(replacement of the shaft sleeve at the stuffing box / replacement of the mechanical seal).

Loosen nuts (M1) and remove the tie bolts (25).

Lift the suction casing (3) (careful blows with a rubber mallet on the suction casing tie bolt bosses) and
remove the o-ring (OR1).

Remove sleeve (38).

Dismantle impeller (1) and diffuser (2), remove key (PF2). Mark the sequence of all parts for the
assemble.

Remove the stage casing (60).

Dismantle stepwise the pump to the discharge casing (4).

Clean carefully all parts. If the assemble is performed at a later date, then store the pump parts and
protect it for corrosion.
Assembly
In opposite sequence.

3. Repair

Clean all parts and check for wear.
In case of excessive wear, parts must be reworked or changed against new parts. Remove disposals.
In the majority of cases it is practicable (if damaged absolutely necessary) to replace roller bearings and
sealing elements (O-rings, shaft seal ring, V-rings, aso).
Mechanical seals do not seal reliable, if they have run already for a longer time (fine grooves of the slide faces
do not find together after assemble as before). This is the reason why a new mechanical seal should be
assembled and the dismantled mechanical seal can be sent to the seal supplier for renewal of the seal faces.
At required refinishing operation on the casing parts, impellers and diffusers pay attention that all centring
devices run centric each other and that all plane faces are normal to the rotation axis.
Attention: One exception is the centring of the bearing bracket, which is eccentric in some cases against the
bearing bore to compensate the shaft deflection.

3.1 Impeller wear ring clearance

If the impeller wear ring gap is worn, it is possible to level the wear ring and the hub of the impeller. It is
required to insert a wear ring or a bush into the diffuser, which has a special inner diameter simulating the new
condition.
Wear ring clearances see table in chapter 3.3

3.2 Clearance of the balancing drum

If the drum clearance is worn, that means it exceeds the maximum value of the table in chapter 3.3, then it is
required to replace the balancing drum and the balancing bush by a new one.
The size of the clearance depends on material and if required inquire the value in the service department.
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