Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • 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!

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

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Wet well pump noise.

Wet well pump noise.

Wet well pump noise.

I know the manufacturers dry well factory test noise level for a pump, but I am using the wet well version.  Surely submersing the pump will damp the noise produced (no pun intended ).  
How do I work out the equivalent noise for the operating submersible pump??

RE: Wet well pump noise.


As a multi stage submergible pump manufacture I will try to offer a little, but I’m not real sure what you’re after with this so please be patience with me.

Noise is a vibration.  The short answer is for you to use a device (transducer) to measure the vibration levels at the pump during operation.  Being submerged in a liquid will dampen the audible noise of a pump, but the audible noise levels themselves are not the problem.  The problem is; “what is the vibration that is causing the noise.”  Any source of vibration will cause a shorter than expected run life from the pump.

Some sources of vibration:

There is fluid shear when operating a submergible centrifugal pump.  There are methods to limit the effects of fluid shear in a centrifugal pump during the design phase of the pump, but fluid shear does exist and contributes to the overall pump vibration.

If there is air or vapor entering the pump with the liquid stream there will be additional vibration in the pump.  In a perfect world you will only pump a clear, clean fluid stream.  In the real world this fluid stream does not exist.    

Misalignment of any type can cause vibration.  This misalignment can be from many sources, but one that I see on somewhat regular bases is due to engineers not taking thermo expansion of the equipment into account.  If you test equipment in a 70 degree Fahrenheit environment, then operate it in a 280 degree Fahrenheit environment the operating results will be different.  Metal growth will cause close tolerance equipment to fail if it is not taken into account.  As a rule the pump stages themselves are not the big problem for metal growth, but the axial load handling thrust bearing is. Typically thrust bearings have <.003 percent tolerance.

Variable speed drives operating the motor that drives the pump can cause a lot of additional vibration.  If you operate a pump over a given speed range and happen to hit a critical speed it will destroy a pump in a matter of minutes.  I normally use a Holtzer (not sure of spelling) formula for predicting critical speeds, then give it about 5% each side of the predicted speed.  

I’m not sure if this information is what you are after, but hope it helps some!

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

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! Already a Member? Login


Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
The Great Project Profitability Debate
A/E firms have a great opportunity to lead the world into the future, but the industry’s greatest asset—real-time data—is sitting wasted in clunky, archaic ERP platforms. Learn how real-time, fully interactive dashboards in a modern ERP allow you to unlock data that will shape the future of the world. Download Now

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