mag pumps and tubing????

[dclegern]

So I bumped up to a mag 12 from the old mag 7.
It's supposed to have 3 times the flow at 5', and I'm not really seeing it.
The pump manual said to use 1 1/2 inch tubing, but it only has a 3/4 inch outlet.

so I kept using the 3/4 inch tubing for return flow....

Anyone know the spec's or rules on this?

[Sherita]

The rules for most mag pumps are tubing that is twice the size of out outlet on the pump, so if you have a 3/4 outlet, then 1 1/2 is correct.

[dclegern]

I guess i'm wondering. physics wise.....
If the initial flow starts at 3/4 inch@1200 gph, then bridges to 1 1/2. then the flow should be slowed down!!

[Gseclipse02]

you would think it would slow the flow down with more weight from the water in the tubing

[txg8gxp]

Going to a larger tube/pipe WILL decrease PSI, but allow for more flow (GPH). Not only will the larger pipe allow for more flow but the decrease in PSI will allow the pump to push more GPH aswell, if that makes sense

[dclegern]

Yeah, I switch from 3/4 inch tube with 1/2 exit port that was with the original set up.
to a 1 inch from start to finish, and my tank can hardly keep up with the amount of flow.
Had to back down from the mag12 back to the mag9.5 just to keep the water in the tank/sump.
CRAZY!!
Redid my sump to handle the volume..... we'll see!!

[alton]

Mag pumps are made very well but when it comes to pressure there GPH drops very fast. If you took your mag 12 (1200GPH) versus a Pan World 100PXX (1270GPH) and then connected them to your return with a 5' lift, the Pan World would smoke the Mag12. Remember if you are using barbed fittings you are creating more restriction on your flow because a 1" barbed fitting is 3/4" interior diameter.

[dclegern]

The mag 9 with the 1" tubing was pushing more water than the drill ports(overflow) could handle, so I put in a flow valve at the pump, and it seems to have fixed things.
Pray we have no flood!!!

[dclegern]

I still don't think I'm getting the desired 10x turnover in my tank that I wanted.
But it's a huge step up from what was probably only a 4x turnover from before with the 3/4 inch tubing and barbed fittings.
thanks Alton!!!
I wasn't thinking about that.