×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Low Flow Discharge

Low Flow Discharge

Low Flow Discharge

(OP)
We have 2 Pumps runs parallel.  Pump Discharge before Turaround 70-72#. Pump Discharge right after Turnaround 65# of last year. We have about 7# differences ever since.  First we thought that might be we changed out the impeller, with new metal, it might slow down the flow. But now, we don't know what happened, no change in cooling water process, no one did anything to the valves neither the line services. We are looking at some causes such as: Check Valve Stuck, Impeller Wear/Erosion, Obstruction in Suction Line, Lower Turbine Speed.  
Does anyone ever encounter similar type of problem?

RE: Low Flow Discharge

Do you have total flow indication? If so an increase in total flow (in conjunction with decrease in pressure) indicates system change, decrease in total flow indicates pump change.

Do you have before/after vibration spectra which might indicate whether speed has changed?  Supply voltage decreased? Fluid temperature increase or other density decrease?  If only one pump runs, leaking check valve? Pump lift adjusted? Possible wearing problem?

There are certainly a lot of possibilities. What work was done during the outage?  others may be interested to know what type of pump?

RE: Low Flow Discharge

(OP)
Dear sir,

2 Pumps discharging the water from the Cooling Tower.  2 of the running Pumps are Steam Driven (Centrifugal). The 3rd one for back up is the Electrical Driven which is not used.  So the source of Voltage supplied, fluid temperature decrease/increase, pump lift are not the case.  We are ordering a new Impeller because of its delivery time for our January Shutdown.  
My question is what other possibilities you would think that might happened here.  We are thinking:
Check Valve Stuck, Impeller Wear/Erosion, Obstruction in Suction Line, Lower Turbine Speed.
We will have Dead Head measurements for each of the Pump. Does anyone else has any input for this problem.  Thank you ya so much in advance.

RE: Low Flow Discharge

If turbine powered, I'd take a close look at the governer setting and what the actual RPM is that you are running.

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


Resources

Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. Download Now
eBook - Managing the Context of Product Complexity Using the Digital Twin
Keeping track of changes to complex products is difficult—think Aerospace & Defense equipment, new generations of commercial aircraft, and software-based automobiles. A new way to managing the digital context of the physical product is required and the answer is the Digital Twin. This ebook explores the opportunity available for Operations and Maintenance for the Digital Twin. Download Now
White Paper - Trends in Industrial Filtration
Substantial progress has been made in filtration technologies in recent years. New filter media materials, designs and processes have led to filters that are more efficient, reliable, compact and longer lasting. This white paper will discuss the various trends that are impacting operational responsibilities of MROs today and the resources that are available for staying up-to-date on the latest filtration solutions. 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