Effect of Atmospheric Pressure on Pump Lift

[polyroly]

I am sizing a small jet pump to lift a low flowrate of water into a building for a temperature measurement.
The problem is that a high amount of lift is required.
I have a pump selected that has a good amount of lift but the disclaimer says the capacities are given at near sea-level conditions.
The location is at 481 m above sea level and I am wondering what impact this elevation difference will have on the suction lift?

Thanks!

 

[katmar]

Ask the manufacturer.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[RayA1004]

If you're set on using a pump to move the water to the measuring device, I agree with Katmar - check with the manufacturer.
I tend to throw in my 2 cents worth (and I have a handful of pennies).
How accurate does the reading have to be? Would pumping a low flowrate stream into a building affect the reading to a degree that you'd consider significant?
Have you considered putting the thermometer/thermocouple/RTD into the bulk of the stream?

 

[polyroly]

Thanks guys. I had asked the manufacturer previously but have not gotten a response. I would like to put the thermocouple out into the water stream but I am getting some resistance from other members of the project group.

 

[Artisi]

First up, why are you using a jet pump?

"The problem is that a high amount of lift is required" --is this suction "lift" or are you referring to discharge head?

At 481m ASL the effective maximum suction "lift" achievable from any pumping system will reduce by something like 0.7m.

 

[polyroly]

I am referring to suction lift. The discharge head requirements are negligible.

Is there something wrong with jet pumps?

Where did you get 0.7m from?

 

[Artisi]

The question "why are you using a jet pump" was to try and establish the "suction" lift - what suction lift are you talking about?

Absolutely nothing wrong with jet pumps in the right application - however, as your application is not fully explained would you be better served with a standard pump?


Where is the eductor(jet)located in your pump system - at the pump inlet or external to the pump (at the inlet to the suction pipework)?