air gap built into Fleck 7000 drain?

[lifespeed]

I was just looking at the waste pipe install my plumber did. It is 1-1/2" ABS with P-trap serving both a carbon filter and softener tank that are timed not to overlap. It does not have an air gap.

I have observed them in operation. At the end of the drain cycle the clear hoses to the valves quickly fill with air, leading me to believe the valve does not allow a cross-contamination situation to occur.

Is this an OK situation or should I install an air gap just so a theoretical building inspector will pat me on the back and tell me I did the right thing, even though it is safe as-is? No, I'm not going to get this inspected.

[F6Hawk]

Air gap. Absolutely. I put mine into a cap with an air gap above the p-trap in the septic lines, and went one step farther and drilled 3 or 4 air holes in the cap so no vacuum between the septic and softener drain lines could occur.

[Tom Sawyer]

Post a picture of the trap please.

[lifespeed]

Post a picture of the trap please.

Here it is. The 1/2" drain hoses are a good 14 - 16" above the P-trap. It is hard to see, but there are actually two entering the 1-1/2" drain via a tee.

Perhaps all I need to do is drill a couple holes where the tee adapts to the larger ABS drain to break the vacuum.

[Gary Slusser]

An air gap is meant to prevent contaminated sewage water from touching the end of the drain line if the drains in the house were to block up. That's to prevent possibly contaminating the water in the softener. Nothing to do with a vacuum.

The down side is that with an air gap and a blocked drain, you get sewage water all over the floor.

Now IMO and you may agree, if you have a blocked sewage line, you have much more to worry about than if the water touched the end of your softener's drain line, but that's just me...

[johnjh2o1]

The two lines should just go into a open line very much like a clothes washer. There should not be a solid connection between the waste line and the backwash lines.

John

[F6Hawk]

An air gap is meant to prevent contaminated sewage water from touching the end of the drain line if the drains in the house were to block up. That's to prevent possibly contaminating the water in the softener. Nothing to do with a vacuum.

But it does have to do with a vacuum... you can have an air gap between the discharge hose of a softener and the sewage, but a seal between the stand pipe and the discharge hose, and if there is a malfunction with your valve, it can suck raw sewage into your DW lines thru the valve as long as there is enough water to fill the stand pipe. Likely? No. But possible. (think valve malfunction that allows the drainline to suck water at the same time a toilet is flushed, thereby providing enough water to fill said stand pipe). I am sure it would never pass a code inspection.

I'd also propose that what he is showing (and what I described in my house above) is an air BREAK, not an air GAP. Sticking a washing machine drain line into a stand pipe is an air break as well. An air gap requires vertical separation between the lines, with nothing touching.