Pro/Forums - View Single Post - My theory of calculating necessary head in a loop

bobkoure · 12-28-2004, 08:55 AM

Here's a thought experiment.
Take a pump with 3.5' head. Connect the inlet to the outlet with a single length, say 8' of tubing, ID large enough not to be much of a factor. Garden hose should be fine.
With the tubing laying on the same surface as the pump, it should work fine, right? (water goes 'round).
Now lift the center of the loop so it's higher than 3.5' above the pump.
Does the flow stop? If you think it does, maybe you should actually try the experiment, rather then just think about it. If you don't think the flow stops, then how is a closed system different from a single length of hose?
[edit] BTW, mounting a rad like that, with inlet and outlet at the bottom is not un-usable but will present problems with air being captured in the top tank, at least at fill-time.[/edit]

12-28-2004, 08:55 AM	#6
bobkoure Cooling Savant Join Date: Feb 2003 Location: USA - Boston area Posts: 798	Here's a thought experiment. Take a pump with 3.5' head. Connect the inlet to the outlet with a single length, say 8' of tubing, ID large enough not to be much of a factor. Garden hose should be fine. With the tubing laying on the same surface as the pump, it should work fine, right? (water goes 'round). Now lift the center of the loop so it's higher than 3.5' above the pump. Does the flow stop? If you think it does, maybe you should actually try the experiment, rather then just think about it. If you don't think the flow stops, then how is a closed system different from a single length of hose? [edit] BTW, mounting a rad like that, with inlet and outlet at the bottom is not un-usable but will present problems with air being captured in the top tank, at least at fill-time.[/edit] Last edited by bobkoure; 12-28-2004 at 09:00 AM.