prov356 said:
The Reef Central Calculator is a total system calculator for systems under pressure, hence the calculator output of total head loss in feet and in PSI. If it was a "drain" it wouldn't include the pump brand/type factored into the equation.
You'/re right, my bad. I thought by your conclusion you'd used the other calculator. Should have looked.
Still not clear to me though how you can overcome the 3/4" bottleneck at the pump inlet and outlet just by using 1" pipe in the rest of the system. I'm moving 600gph (measured) through my 3/4" returns at 5' head with elbows, check valves, etc. That's the size outlet on the pump. Not trying to be argumentative, just understand.
The inlet and outlets are already factored into the pump ratings - meaning that even though a pump has a 3/4" inlet/outlet, you don't have to worry about the "bottleneck" and the pump rating at 0' of head will still be the maximum GPH output. Does that make sense?
I've gone to a couple of manufacturing sites to showcase the thought behind the idea of using larger diameter plumbing.
I also like to think that the theory behind using larger diameter plumbing is like dragging your hand across sand paper (Your hand is the water, the sand paper is the PVC plumbing).
When you use larger diameter plumbing, it's akin to placing your hand casually on the sand paper and slowly moving it across the surface. Does it resist? Yes, but you are still comfortable and your hand is clearly unaffected.
When you use small diameter plumbing, it's like pushing down as hard as you can on the sand paper and ripping it across it as fast as you can. Does it resist? Yes, a lot more than the previous model, and your hand is now scratched up and possibly bloody (depends on what grit sand paper you were using :wink: ).
So, because the pressure in the
pipe is less, there is less friction, thus less head loss. Subsequently, since you have reduced the head loss, the pump can perform at a level farther out on the pump's curve (i.e. a higher GPH) and because of that you'll get a higher PSI at the end of the line (i.e. UGJ nozzle).
Anyhow, here are the two answers from MagDrive's FAQ section and Sequence's (Reeflo) FAQ section . . .
Danner mfg. (MagDrive)
". . . [T]he friction or resistance added by the pipe and fittings the water must flow through is the Friction Head, which is added to the Static Head to get the Total Head. You can keep your Total Head as low as possible, maximizing the flow from your pump, by keeping the friction losses in the plumbing as low as possible, usually accomplished by using as large a diameter pipe and [the least amount of] fittings as possible.."
Sequence (Reeflo)
"There are two elements that cause pressure requirements in your system; vertical lift and
“FRICTION LOSSâ€