×
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

Jobs

Pump performance

Pump performance

Pump performance

(OP)
In a plant a condensate pump is not performing upto the desired ( also designed) performance.

The NPSH required for the pump is 1 meter where as the available is 3 meter. ( The condensate temp is 96 degree centigrate and the tank is open to atmosphare.).

The duty point mentioned on the data sheet says follwing:

Capacity : 1.5 m3/hr
Head     :20.7 meter
Condensate Temp : 85 degree centrigrate.

I wanted to know that if the condensate temperature increases from 85 to 96 degree celcius the pump shall not delever duty point parameters though the NPSH available is more than required even at 96 degree celcius.

RE: Pump performance

What is the pump delivering for flow and head and how does it compare to the pump curve?
Have you checked the inlet piping for pressure drop to ensure you have at least 1 m available head?
Is there a suction strainer in the line that could be partially plugged and taking a larger than normal pressure drop?
Are you confident in your data, for example, the flow rate through the pump?
Is the available NPSH of 3m off the data sheet or is it a calculated value based on 96 deg C condensate?

RE: Pump performance

Hello TS
AS TD2K says, you have to identify and to calculate all the pressure losses in suction/inlet system and to balance it with the pump required NSPH, expressed in the pump data-sheet. See any common Hidraulic manual, how to perform that basic calculation. Be aware of the temperature effect, which is related with the respective vapour-pressure it means, as higher is the condensate temperature, lesser the difference [required NSPH - installation NSPH]. Better always to consider a positive (+) margin for security reasons 20 ~ 50 %, shall we say.
Good comissionning!
zzzo    

RE: Pump performance


 always start with the easiest part

do you have a meter at pump discharge ? how much it reads ?have u taken pressure measurements ? collect data do simple calculations and check on the curve where pump is operating and why ?

 cheers!

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!


Resources