Sizing up water pump...

[flamenco-t]

On my 240, I am running 2 Durso standpipe at 1 1/4" from the overflows to the bulkhead and 1" from bulkhead to the sump

I have a 1" PVC from the water pump coming up to a tee, then split in between the two return pipe up to the tank.

My question is this;

The Durso I calculated to drain out about 600 gph each x 2 = 1200 gph going into the sump.

Shouldn't I want at least 1200 gph coming out the pump to reach the two return pipe into the tank ?

Considering 6 ft of vertical line, 3 ft of horizontal line and 2 90 degrees, I'd imagine that I need a pump that is capable of doing 10 ft of head loss and at 1200 gph, this means I need somewhere between mag 24 and comparable pump..

It seems kind of a lot of pump (mag 24) to be able to match the flow of the return from the dursos.

Any input ?

stan

 

[Volenti]

The overflows will only return the water available to them, there's no lower limit to flow, only an upper one.

If you want to have 1200gph of flow back into the tank then you will indeed need a pump capable of 1200gph at ~10' of head, you will need the manufactures head curve to figure that out.

 

[Tongue33]

Rather safe than sorry I wouldn't go over mag 18 at 6 feet you are gettin 1200. You will lose alittle more with the 90's but if you go up to a mag 24 it will be too much. At 6' I believe it is around 1850 But not lower than 1800 gph.. And even with the 90's you will not lose enough flow to drop to 1200.

It is best to go with a pump that will not land right on or exceed the drains maximum capacity. mag 18 should be fine.

Strictly my opinion

I have a mag 24 on my 250

 

[flamenco-t]

This is the picture of my setup..

From the pump, it comes up, tee off to the other side. 1 tee and 1 90 degree bend overall.

Now, in order to find out the amount of head loss, do I have to add the other vertical height of the return pipe ? For example..the left side have a pretty straight shot of vertical line from the pump to the nozzle which is 6 feet.

The right side however, have a 3-4 feet of horizontal line and 4 feet of vertical line.

So, with this, when I plug the numbers in the head loss calculator, do I put 6 feet of vertical line or 10 feet or vertical line ?

 

[CHOMPERS]

To make is simple...

Your overflows must flow more water than the pump can return.

Otherwise the filter will always be empty and the pump will constantly be sucking air. Pick any pump that will flow less than 1200 gph (be sure to add wiggle room).

And vertical distance is only vertical distance. The head loss from the fittings and horizontal plumbing is negligible at that flow rate.