Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

Join Eng-Tips
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

Submersible vs Vertical Turbine (Raw Water Feed)

mechprocess (Mechanical)
31 Dec 08 9:17
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.

 
piffer (Mechanical)
31 Dec 08 17:46
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.
mechprocess (Mechanical)
31 Dec 08 20:26
I did say raw water feed in the header.  
Artisi (Mechanical)
31 Dec 08 20:45
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.
rmw (Mechanical)
31 Dec 08 21:40
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
TenPenny (Mechanical)
5 Jan 09 10:14
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.
dabluffrat (Mechanical)
3 Feb 09 16:14
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.
wimple (Mechanical)
5 Feb 09 1:54
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
 
stanier (Mechanical)
8 Feb 09 22:25
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.

wimple (Mechanical)
9 Feb 09 15:28
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

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Back To Forum

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close