Quote:
Originally posted by unregistered
jeez fellahs, its a super simple test yielding an approximation;
no need to try to 'over-engineer' it
bigben2k
take your pump's deadhead pressure, convert the units to in.H2O (or ft.H2O); and rest assured, NO water will come out the top
- well, there is a surge when the pump starts up - so add a foot (or pinch it off)
-- the size of the risers is irrelevant as there is no flow through them
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But over-engineering is what we do best!
Besides, if we didn't do that, we wouldn't have noticed that this simple test also involves taking the result of the weight of that water column, convert it to psi, and multiplying it by two, since the rig is still running, and the pump will split its load between the cooling loop and keeping that column up.
The part that was hard for me to understand is how this tube on the intake isn't going to suck air in: I have to remember that its the column at the pump output that's preventing that from happening, assuming that there's been a good enough quantity of water added. It's otherwise clear that both these tubes will have the same level of water, when the pump is off, as they balance each other out (through the pump, assuming that it's not an odd pump).
The result, a difference in height of coolant level that stabilizes at a certain height, will indicate the pressure drop between the outlet and inlet, but not the actual pressure readings. Few people know that the pump inlet's pressure is negative (i.e. below atmospheric).
I don't think that Skulemate has anything to worry about. I would expect pressure drops to be around 5, maybe 10 psi in the worst of cases, which translates into... what's the calculation again?