Drain plumbing question

[astreck827]

So I just want to double check myself on a plumbing situation. I want to add a new frag tank to my system, but the only place that works is on the other side of a door. It’s in a partially finished basement, and the bottom of the door is about 4” from the floor. I want to run my plumbing across the floor in front of the door and then build a small step up platform to conceal it… my main question is can the drain go down and then back up to get over the rim of the return sump? In my head, it works because it will still be well below the water level in the new tank, but I want to make sure I’m not setting myself up for disaster. I have included a crude drawing of the idea… of course there will be multiple drains etc but I just want to make sure the concept is solid.
Thanks!

 

[theMeat]

If where the water enters the pipe is higher than where the water exits it will work. But you will accumulate debris in lower part of pipe because it will essentially be a trap, like you have under your sink

 

[Snoopy 67]

And it will continue to drain until the siphon breaks unless you pump it back.
If the pump ever dies you have a flood.

 

[TheBear78]

I think that even a moderate flow would prevent debris build up like the U-bend on a sink in which the water is stagnant for long periods.
My first concern with this would be how to prevent siphoning. A siphon break would need pipework above the waterline of the higher tank but it would probably pull a lot of air in with such a drop.

 

[astreck827]

And it will continue to drain until the siphon breaks unless you pump it back.
If the pump ever dies you have a flood.

I don’t really get this logic. The new tank would have an overflow box just like a normal tank would… only difference is there is a dip in the drain line before it gets to the sump. The siphon would break as soon as the water gets below the overflow box just like any other tank.

I think that even a moderate flow would prevent debris build up like the U-bend on a sink in which the water is stagnant for long periods.
My first concern with this would be how to prevent siphoning. A siphon break would need pipework above the waterline of the higher tank but it would probably pull a lot of air in with such a drop.

Again, wouldn’t the siphon break just be when the water level gets below the overflow box? I didn’t draw the overflow in the picture because that wasn’t what I was concerned about. I just wanted to make sure the dip wouldn’t cause an issue.

 

[astreck827]

If where the water enters the pipe is higher than where the water exits it will work. But you will accumulate debris in lower part of pipe because it will essentially be a trap, like you have under your sink

I planned to have unions on either side of the low section for clean out. I’m hoping there won’t be a terrible amount of debris, it is going to be a bare bottom frag tank.

 

[RichReef]

Siphoning won't be a problem if the frag tank pipe in the pic is the overflow. It's going to be taking on air anyways. It's the return line that usually has siphon problems.

The problem I see with setup is flushing and uneven water flow through the pipe. Filling, draining, filling, draining. It will work but if you want even, quiet draining you will need stand pipes on each side above the frag tank water line to relieve pressure to create an even, steady flow.

 

[astreck827]

The problem I see with setup is flushing and uneven water flow through the pipe. Filling, draining, filling, draining. It will work but if you want even, quiet draining you will need stand pipes on each side above the frag tank water line to relieve pressure to create an even, steady flow.

I was planning on doing two drain pipes herbie style, keep one in a siphon and let the other handle a trickle.

 

[Snoopy 67]

If you don't explain it or draw it we have no idea it is there. Your drawing shows an elbow out of a tank down to another tank.

 

[Dburr1014]

Siphoning won't be a problem if the frag tank pipe in the pic is the overflow. It's going to be taking on air anyways. It's the return line that usually has siphon problems.

The problem I see with setup is flushing and uneven water flow through the pipe. Filling, draining, filling, draining. It will work but if you want even, quiet draining you will need stand pipes on each side above the frag tank water line to relieve pressure to create an even, steady flow.

I don't understand what you mean by uneven water flow, filling draining filling draining can you explain that?
I see it as once it's got water in it it's going to keep flowing like any other overflow siphon. The exit is still below the tank water level it would never stop and need to be, what you say, refilled.
I don't see why it wouldn't work. I would just plan once a year take the pipe out give it a good cleaning put it back together.

 

[astreck827]

If you don't explain it or draw it we have no idea it is there. Your drawing shows an elbow out of a tank down to another tank.

I did state that the drawing was crude and there would be multiple drains. I appreciate everyone’s advice but my question was about the dip and rise.

 

[RichReef]

I don't understand what you mean by uneven water flow, filling draining filling draining can you explain that?

It's easy to think that the water will flow evenly. If the flow is very slow, yes. But that elbow at the sump is going to need to be vented for even water flow. The water flowing down the pipe into the sump is going to create a vacuum. When the pressure in both pipes is uneven the water flow can not remain even.

You can set it up as you have it. If there is a problem you can add the stand pipe later. If it was me I would stand pipe both sides. Honestly it's not much work and doesn't cost a lot.

 

[TheBear78]

Gravity will sort out the flow. If there is a constant supply of water at the top, it will reach the lower tank. That is not in doubt.
Crude drawing or not you didn't mention that the pipe will take water from an overflow. It makes a big difference.
Don't be offended by the comments about siphoning, it's not criticism just a caution as I imagine many people (myself included) could see that pipework sucking a lot of water from the higher tank.
Depending on how flow is controlled you may struggle to keep the noise down but as far as transporting water is concerned, yes it will work.

 

[WVNed]

The only problem may be at the end where it goes up and over and then down. That can trap air. A bubble will sit in the high point and allow some water through but not the full amount expected. As someone mentioned this can be prevented with a standpipe at the side of the sump.

 

[astreck827]

The only problem may be at the end where it goes up and over and then down. That can trap air. A bubble will sit in the high point and allow some water through but not the full amount expected. As someone mentioned this can be prevented with a standpipe at the side of the sump.

Standpipe on sump side… so would this be and air release at the high point before going back down into the sump? Essentially a tee instead of an elbow down?

 

[Dburr1014]

It's easy to think that the water will flow evenly. If the flow is very slow, yes. But that elbow at the sump is going to need to be vented for even water flow. The water flowing down the pipe into the sump is going to create a vacuum. When the pressure in both pipes is uneven the water flow can not remain even.

You can set it up as you have it. If there is a problem you can add the stand pipe later. If it was me I would stand pipe both sides. Honestly it's not much work and doesn't cost a lot.

Okay, I understand about the standpipe. Air would get trapped, good to vent out out.
But that setup would not create a vacuum so it won't stay at an even rate. That would defy the laws of physics. Constant in has to have a constant out.

 

[WVNed]

Standpipe on sump side… so would this be and air release at the high point before going back down into the sump? Essentially a tee instead of an elbow down?

Correct
Here are mine on the top left being built

and running

My drains go down behind the tank, through a wall and then rise up and over into this tub.

 

[Roli's Reef Ranch]

I don’t really get this logic. The new tank would have an overflow box just like a normal tank would… only difference is there is a dip in the drain line before it gets to the sump. The siphon would break as soon as the water gets below the overflow box just like any other tank.

Again, wouldn’t the siphon break just be when the water level gets below the overflow box? I didn’t draw the overflow in the picture because that wasn’t what I was concerned about. I just wanted to make sure the dip wouldn’t cause an issue.

You're right... people be overthinkin' things.