Throttling Suction Valve 2

[arm83]

Guys, I got this quote from a website:

"Pumps are normally throttled with a discharge valve, but in rare cases it can be done with a suction valve.

1. You must have sufficient NPSH to prevent cavitation.
2. Suction throttling prevents the over heating caused by discharge regulation. This can be important with fluids like jet fuel where the additional heat could vaporize the fluid. "

Is the above correct information? I have read in most books that the suction valve should ALWAYS be fully open in order to prevent cavitation and uneven forces in the pump. Can someone please clarify?

 

[Artisi]

25362 (Chemical)

For interest look at super cavitating pumps.

 

[786392]

I assume, there are auto adjusting systems of throttling on suction side of some special service pumps,although can not specifically recall any;

but there should be many knowledgeable's around to enlighten/ update us I believe.

Best Regards
Qalander(Chem)

 

[25362]

Artisi, thanks. I already knew about supercavitation. See thread407-218061 started by none other than...

BigInch, you're right, creative thinking will, however, last beyond QA/QC. It was Wernher von Braun who said: "I have learned to use the word impossible with the greatest caution".

Besides, having acted most of my professional life as a process engineer, when speaking about the subject of curiosity, lateral thinking, brain storming, and the like, I recommend reading David Saletan in his Creative troubleshooting in the chemical process industries, Chapman and Hall.