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Submersible vs Vertical Turbine (Raw Water Feed)

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mechprocess

Mechanical
Jun 23, 2004
39
What are the pros and cons for using a submersible pump instead of the typical vertical turbine pump?

I read that submersibles have problems with thrust bearing load limitations during starts and stops, oil seals leakage, maintanence repair costs, motor efficiencies etc.

My wet well is about 20 feet deep.

 
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mechprocess,
you didn't mention the application. Most submersible pumps have limitations on metallurgy and max. operating temperature. Other than that, I think submersibles are generally easier to service and maintain. There is no comaprison between pulling a vertical turbine pump and a submersible. Also, there are some excellent solids handling submersibles that are very reliable and energy efficient.
 
Yes you did, but tells nothing - also - how about duty in terms of flow and head - are you discussing 0.5kW or 1000kW pump units.
There are some pretty smart people here - but we aren't mind readers.
 
Geee Artisi... Earlier I had a very similar response all typed up and ready to submit and then relented and deleted it and closed the thread. You expressed my reaction to this thread very well. I've dealt with some really awful "raw water" using both submersible and VT pumps but I would need to know more to be able to offer an opinion if I turned out to be qualified to do so.

rmw
 
Generally, if your application requires 200 hp or less, a submersible might be a candidate, but you have to consider that the motor will need a certain velocity of water past it, so you have to look at the well diameter and flow rates...this is me assuming you mean a submersible turbine pump, not a submersible sump style pump.

You make mention of a 'wet well', which suggests to me that it's more of a sump, in which case I would suggest a vertical turbine will be your most cost effective and maintenance effective choice.

Much depends on your flow rate, and the properties of the water.
 
submersible pumps save floor space, but aren't near as efficienct as a vertical turbine. submersible motors fail often. vertical turbines are a hassle to pull but the packing/seal and motor can be serviced w/o pulling the pump. vertical pumps are going to be more expensive... most submersible pumps are built off the shelf and can be shipped within a matter of 2-3 weeks.
 
Hi

If we are talking about borehole submersible pump for raw water pumping, I would say that such pumps offers good efficiencies. They are quite limited by water temperature (generally below 60°C ; for corrosive water could be even lower limit as the corrosion rate increase with temperature).
The cooling of the motor is ensured by the surrounding flow that is pumped but the diameter of the well shall be appriopriate with regard to the diameter of the pump in order to maintain a fluid velocity sufficient for the cooling.
To my knowledge, such pumps are designed with a lifecycle of 10 years. But water analysis should also be available to select the appropriate metallurgy as for exemple presence of Ammonia, type of water minerals etc in order to avoid in corrosion issue that could shorten the life of the pump.

By selecting a reputed manufacturer, I dont expect issues with such pumps.
Rgds
 
Wimple,

KSB and ABS make pumps in super duplex stainless steel so i would not worry too much about the corrosion aspects.

Submersible pumps may prove to be more effciient and better suitaed to parallel operation that turbines. turbines suffer from vortexing more than submersibles.

Submersibles have a duckfoot bend that is hard to maintain.

For my money I would use a submersible every time over a turbine.

You can get submersible turbine pumps.

 
Stanier

For Info KSB makes submersible borehole pumps also with impeller in Noryl (derived from plastic), quite good solution for corrosion and appreciable mechanical resistance but the head start about 20 m.

Considering about 6 meter static head, I dont know what about the dynamic head but I deem the application will be at the very limit for this Mfg.

Rgds
Wimple
 
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