Yes, I know, as I've read that (Pump Handbook) excerpt carefully, and I've seen something similar reproduced elsewhere in standards over the past 20 years or so.
My point is that the fluidedesign.com image excerpt from "The Pump Handbook" contradicts most other sources when it comes to flow coming into a centrifugal pump from above and the proper orientation installation recommendations for an eccentric reducer on a pump suction (FOT vs. FOB).
Where is entrained air/vapour going to collect after extended operation in the visual scenario proposed by Figure 1 at http://www.fluidedesign.com/download-free/guidel_pump_syst-extract.pdf ?
I'm assuming that there will be some turbulent flow characteristics due to the change in direction through the elbow (and also any upstream combination of X-Y-Z axis piping) and that air/vapour would naturally collect in the high "cavity" point of a FOB reducer. Then, this collection of air/vapour could slowly impinge on the impeller or let loose all at once. This IS fluid dynamics analysis, so event prediction is one of those things that cannot be reliably measured.
Am I wrong in my interpretation or am I going straight to pump hell for being a heretic (or, even worse, condemned worldwide as being a moron in the piping design community)?
Maybe some inexperienced draftsman made a drawing mistake and it wasn't caught by the editors for all these years.
And as usual, I'll add the caveat that I'm just asking questions since the only dumb question (within reason) is the one you didn't ask.
Paul
Jacques Chaurette wrote:
> The Pump Handbook actually recommends both situations, depends on whether the
fluid is coming horizontal or from the bottom (FOT) or if it is coming from the
top (FOB).
Received on Fri Feb 25 22:27:00 2005
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