Help! What am I doing wrong? Air in overflow pipe

  • We are currently upgrading MFK. thanks! -neo
MATTCB;3952180; said:
are youre overflow pipes in the tank or in a seperate overflow box?

I don't have an overflow box. Just 4 pipes sticking out from the bottom
 
To those who say they have a 1000GPH pump running w/ just two 1" overflows. How many elbows does you overflow have for each overflow pipe??
 
technically speaking 6 plus a 45. Actual elbows in place is 4, but my design is a bit different.

Here's a pic of my overflow:
DIY_Intake_12.jpg
 
frootloops;3953877; said:
I'm having a hard time finding 45 degree elbows here that are made of PVC.
I'll send you some 45's if you send me some of that blue pipe. :D The Philipines is the only place that it is available (that I know of).


Things get weird when you approach the maximum flow of the pipe (sucking air, etc.). The horizontal run complicates it somewhat too. The water doesn't flow well horizontally, and with air in it, the problem is compounded. Since you have the slope, the air is trying to go the other way. The ideal solution is to vent the horizontal run and give it a downward slope of about 1/2" per foot of run.

The idea of having a larger riser inside the tank does work. It allows more water to enter the pipe and it bleeds the air out. The water builds up at the bulkhead fitting (the bottle neck) and fill the lower end of the pipe. The air rises and vents out of the center of the water flow (as in the void in the center of the flow in your pictures).
 
CHOMPERS;3954019; said:
I'll send you some 45's if you send me some of that blue pipe. :D The Philipines is the only place that it is available (that I know of).


Hahahaha if only I could do that. It would probably cost me an arm and a leg to ship a 20' piece of pipe to the US :ROFL:

The air going the opposite direction of the water flow makes sense to me. I chopped the 4 horizontal pipes as I think they are the limiting factor. The longest pipe travels close to 6 feet before dropping to the sump.

What remains in each overflow pipe now is 1 elbow at the bottom. Will test to see if it works now. I'll post some pics later to share my findings so that those wanting to make the same design won't commit the same mistake.
 
The ideal solution is to vent the horizontal run

Just like an unvented bath drain line...SLOWWWWWW.
Add venting(air-over-water) and away it goes.

Was that the sound of a nail being hit on it`s head...
Chompers got it right.
 
Here are the modifications I made tonight

Before
ofpipes.jpg


After
aftercz.jpg


Under the tank
stsump.jpg


I'll do a test run tomorrow. I'll let the pvc cement dry overnight
 
ok how about a tank shot I am wondering what your tank looks like
 
CHOMPERS;3954019; said:
The idea of having a larger riser inside the tank does work. It allows more water to enter the pipe and it bleeds the air out. The water builds up at the bulkhead fitting (the bottle neck) and fill the lower end of the pipe. The air rises and vents out of the center of the water flow (as in the void in the center of the flow in your pictures).

Is this what you mean by a larger riser? Because I have no idea what it is..:confused:

riser.jpg


Will the pipe on the right take in more water then the pipe on the left?
 
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