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!
  • Students Click Here

*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

Pump Flowrate with no flow meter?

Pump Flowrate with no flow meter?

Pump Flowrate with no flow meter?

Hi, I'm getting some varying answers to this question but I think its a simple principle question.

CAN I read the flow rate of a centrifugal pump if I only know the suction pressure, the discharge pressure and I have a the manufacturer pump curve?  (If yes, how do I use the pump curve to get the flow rate?)


RE: Pump Flowrate with no flow meter?

Assuming the manufacturer's pump QH characteristic curve is steep (neither flat nor drooping) and indeed represents the pump's performance, enter the "head difference" obtained from the pressure readings and the specific gravity of the fluid at the ordinate, and the intersection with the curve will tell the flow rate on the abscissa.

RE: Pump Flowrate with no flow meter?

The above suggestion from #25362  will only give you a very rough indication of the flow rate, you should also check pump speed against the performance curve and make any corrections but more importantly calculate the input power. Having said this, from my experience you will probably end up with a bunch of numbers that will be confusing and  contraditory.

RE: Pump Flowrate with no flow meter?

   Expanding on artisi's cited need for on-site vs test curve speed comparisons/adjustments, one should also compare line voltages and pumped fluid temperatures between on-site and manufacturer's test curves. It is not a simple matter to obtain correct voltage adjustments (which influence running speed) to head readings and it may be a rare occurence that this is done by the manufacturer for each of his pump designs. For a very large production order, one of our pump vendors tested more than 6 pumps of a particular design just to get reliable line voltage adjustment data to demonstrate compliance with rated head-flow and input power performance for all the pumps on the order which were individually tested. The prospects of using input power to a drivemotor to verify pump head-flow performance is also somewhat difficult since both the motor and pump hydraulic efficiencies must be known rather exactly. Again, this may entail multiple unit testing to determine the best average of efficiencies which are prone to unit-to-unit variations. As artisi says, all of these complications can make the matching of on-site and manufacturer's performance data a royal crap-shoot, even neglecting system piping variations which frequently exist and alter the slope of the head-flow curves from manufacturer's test results.

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


eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. Download Now
White Paper - Industry 4.0 and the Future of Engineering Education
With industries becoming more automated, more tech-driven and more complex, engineers need to keep their skills and knowledge up to date in order to stay on top of this wave—and to be prepared for the Industry 4.0 future. The University of Cincinnati offers two online Master of Engineering degree programs designed specifically for practicing engineers. Download Now
eBook - The Design Gridlock Manifesto
In this eBook, you’ll learn 6 ways old CAD technology slows your company down and hear how design teams have put those problems to rest. “The Design Gridlock Manifesto” shares first-hand modern CAD experiences from 15 companies around 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