Disassembly & assembly instructions single stage centrifugal pumps series TCHM & TCTM
3
It is important to adhere to the following before working on the pump:
- use the appropriate steps to stop the pump
- close the isolating valves at suction and discharge piping
- wear the safety clothing (hard hat, safety glasses, gloves, safety booths, etc.)
- disconnect the electrical power to the motor and all the electrical instrumentation and, if necessary, disconnect the
electrical cables
- if the pump is handling hot liquids, let it cool down to ambient temperature
- drain the pump casing through by removing the drain plugs, rinse the pump with neutral liquid, if required
- adopt all safety precautions when the pump handles hazardous liquids, pollutant or toxic; these liquids
as well as the liquid used for rinsing the pump must be collected and disposed of with the maximum caution
and always in compliance with the local safety regulations.
To remove the pump and the motor (if required) from the installation proceed as follows:
- remove the bolts on the suction and discharge flanges
- disconnect any flushing lines, accessories and/or instrumentation connected to the pump assembly
- remove the motor, if necessary, by removing the anchor bolts from the motor flange
- remove the pump by removing the bolts from the pump’s feet
- disconnect the pump from the installation with caution, do not damage any components
- refer to the “Operating manual for centrifugal pumps” for instructions on transporting the pump.
2 – DISASSEMBLY AND ASSEMBLY
2.1 – DISASSEMBLY
(Refer to sectional drawings fig. 1 and 2 of chapter 4).
To remove the impeller VDMA 230 from the pump casing VDMA 102 remove the nuts from the studs VDMA 902.2. Pumps
fitted with Vortex type impeller, series TCMT, remove spacer ring VDMA 110 from pump casing or casing cover VDMA 161.
Remove impeller nut VDMA 925, impeller VDMA 230 and impeller key VDMA 940.2 from shaft VDMA 210.
Measure (making a record) the location for seal locating ring VDMA 485, or mark its location on the shaft, then loosen the
set screw VDMA 904, remove the locating ring from the shaft and remove the seal rotating part VDMA 433.2.
In the event the mechanical seal is fixed on the shaft with its own set screws then the locating ring may not be in the pump
assembly.
Remove the nuts from studs VDMA 902.1, remove casing cover VDMA 161 from lantern flange VDMA 341.
Particular care should be given when removing the mechanical seal components from the pump, mechanical seals are
fragile and may easily get damaged when mishandled.
Remove the stationary mechanical seal face from the casing cover, replace if necessary.
For complete pump disassembly proceed as follows.
Remove bolts VDMA 901, remove motor from lantern flange, remove snap ring VDMA 932.1 and shaft complete with snap
ring VDMA 932 and ball bearing VDMA 320.
Remove snap ring VDMA 932 and the ball bearing from the shaft.
Finally remove the radial seal ring VDMA 421 from bushing VDMA 542.
2.2 – ASSEMBLY
Proceed with visual and dimensional inspections of the components to be replaced (use only original parts from
Pompetravaini), check the parts for wear and tear (for critical dimensions see tab.1 and 2 on chapter 6).
When in doubt, contact Pompetravaini or the closest representative.
To replace the wear rings (only for TCHM series) VDMA 502, it is necessary to remove the set screws VDMA 904 and
remove the wear rings with a gear puller or, if it is too difficult, machine them off with a lathe.
It is good practice to replace all gaskets even if they do not show any defects, replace also bearings and mechanical seals
that have excessive play or grooved faces.
Thoroughly clean the parts with suitable cleaning products that are also compatible with the pump materials.
The bearings should be washed with a solvent or Diesel fuel, let them dry and then oil them. To facilitate their installation
over the shaft it is required to pre-heat the bearings to about 80
0
C.
If there are no complications and the components are free from defects, wear or markings over the sealing areas, the pump
assembly can be done proceeding with the sequences in the reverse of the disassembly.
Assembly of the pump wear ring should be done without force to prevent damages. To help keeping the gaskets firm in
their respective sealing faces, it is suggested the use of compatible liquids such as oil or equivalent fluid.
Fig. 3 in chapter 6 lists recommended torque values for various screws and bolts in relation to their diameter.
ONLY FOR TCHM
Insert and press the wear ring VDMA 502.1 (if it is being replaced) in the pump casing VDMA 102, drill and tap between
the wear ring and pump casing then install set screw VDMA 904 to secure the wear ring.