Pump modifications

[giuman]

Dear All,
Client needs to move installed submersible pumps from one point to another and this will imply to lower the pressure losses and to work in probable cavitation.
Kindly ask if you know the operations to be done on centrifugal pumps in order to change pump's curve characteristics. I think something like as follows:

- Opening of the pump body
- Extraction of the cutter and centrifugal impeller
- The impeller will be sized and installed to achieve the performance as per the indicated curve
- Replacement of the cutter currently installed to adapt it to the new impeller
- Carrying out tests in workshop to verify compliance with the new performance curve
- Alignment and any additional tests

Can you please indicate if there are additional operations for reaching this goal? In particular regarding impeller?
Thank you in advance

 

[EdStainless]

Buy a new pump designed to work in your new conditions.
Modifying an existing pump will only get you a few percent of change.
If you can't meet the submergance requirement then you will need a special pump.
It will likely have the first couple of stages designed for low intake head.

 

[Artisi]

Pump detail might help with your question, ie make, model etc.
Most small commercial submersible pumps are designed to operate under any condition.

 

[Snickster]

So you are relocating the pump to reduce pressure losses in system. Why would this require changing the impeller? Regardless changing of the impeller should be done with assistance of the equipment manufacturer.

 

[LittleInch]

If the impellor is to be reduced in size within the limits of the vendors pump curves then power will reduce, so so issues I can see.

The change in head can be significant and hence power consumption is reduced.

Key thing is to keep the impellor diameter within the minimum allowed by the vendor.

Not sure what you mean by "cutter" - might be a translation issue or is this a sewage pump which chops solids?

It is very rare for a submersible pump to cavitate due to the flooded nature and atmospheric pressure means NPSHA of 10m or more.