1 + 1 = 1.5?

[Armando]

I need to split the output of a Dolphin 2100, which is a 1.5" fitting.

The manufacturer recommends to not restrict flow to less than 1.5" or the GPH can be reduced up to 40%.

So... If I split it into two 1" pipes would it be OK? Or do I need to go bigger?

TIA!

 

[Pinkskunk]

if the T you are using is the 1.5 to 1" reducer then it is fine. But if you are using the 1" T, then it is not ok.

Example: T = Input is 1.5", Output is 2 - 1".s

I did this for mine and works great.

 

[Clutchcargo]

Well lets see, the surface area of a circle pi*R^2.
So for a:
1.5" pipe, pi*(1.5/2)^2 = 1.767145868
1" pipe, 0.785398163 x 2 pipes = 1.570796

You'll be restricting the flow by about 11% + some for the T, a 1 1/16" pipe would be perfect.

I think you'll be fine going to 2 1" pipes

 

[Matt L.]

Clutch is right. You split flow by the area of the pipe, not by the diameter.

Two, 1" pipes are approximately equal to one, 1.5" pipe. It is always best to round up, though. It can't hurt, space permitting, and will only give you less head loss (higher flow).

If I was in your situation, I would use a 1.5" non-reducing tee. Then I would step the laterals down after the tee from 1.5" to 1.25" (or 1", if you are short on space).

Matt

 

[JayG]

They sell this item for the Dolphin pumps:

Pump Union Tee 1.5 in x Two 1 inch Ports for Dolphin Pump

http://www.marinedepot.com/md_viewItem.asp?idproduct=DP2923

So one would assume it wouldn't be a problem

 

[Armando]

Cool responses.

One of the pipes needs to be 1". But I could do:

1" + 1" + 0.5" (fuge). Maybe this would be better?

JayG the problem with that fitting is that I'd prefer to have a true union ball valve connected to the pump before the split, for easier maintenance.

 

[Jim Tansey]

Not to nitpick but when doing pipe calculations you need to use actual pipe inside dimensions not the nominal size, 1 inch schedule 40 pipe is 1.049 ID and 1 1/2 pipe is 1.610 inches. As the schedule number gets larger the wall thickness gets larger, the OD always stays the same, so as the wall thickness increases the ID gets smaller. standard schedule numbers are, 10, 40, 80, & 160, 40 is what we see most.

Jim

 

[Armando]

After reading reports of Dolphin pumps having leak and power consumption problems I am leaning towards getting a Sequence pump instead. Good thing is that this still aplies, as the Sequence output is also 1.5".