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.
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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.
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.
Post a picture of the trap please.
No, plumbing ain't rocket science. Unlike rocket science, plumbing requires a license!
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.
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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...
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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
johnjh is correct here. As long as there is not seal between the crain lines and the standpipe you are in good shape.
No, plumbing ain't rocket science. Unlike rocket science, plumbing requires a license!
As you should know, an air gap is a distance of twice the ID of the drain line from the softener above the rim of the stand pipe or sink I.E. a standard 5/8" OD (nominal 1/2" ID) drain line would be 1" minimum above the high water overflow line of a sink or stand pipe. Otherwise it does not qualify as an approved by code air gap.
So in essence pushing a drain line into a stand pipe, or sticking it into a sink, is no different than a hard connection except air can't get into the stand pipe as it would in a washer stand pipe. BTW, that hard connection would help to prevent the water in the trap from being sucked out. I do not like hard connections and would push the drain line into a stand pipe about 2-3" and anchor it so it can not be knocked out easily instead. Drilling holes is good too, as long as drain water doesn't leak out of them during regeneration.
Click Here to learn how to correctly size or program a water softener.
Exactly. There is plenty of distance from the freshwater to the P-trap. I think all I need to do is drill holes to the side of the drain water 1/2" hose tee entry point to the ABS adapter (so it doesn't spill out) and by definition it becomes an air gap. I don't think it has anything to do with whether it is a "hard" connection or not. In fact, Air Gaps are sold, which are hard connections, but do what I just described by venting to the outside air.
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.
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My apolgies for not being clear on this. Filtration discharge piping may be connected to the drain by means of an air gap or an air break. In his case, the plumber opted to use an air brake which is acceptable by code.
I.P.C. 802.1.5 Nonpotable clear water waste. Where devices and equipment such as process tanks, filters, drips and boilers discharge nonpotable water to the building drainage system, the discharge shall be through an indirect waste pipe by means of an air break or an air gap.
Securing the discharge line so that it does not come loose or out of the stand pipe is highly recommended also. So, what I am sayin here is that the OP's installation does indeed meet code requirements and no changes need to be made.
Last edited by Tom Sawyer; 05-16-2012 at 12:03 PM.
No, plumbing ain't rocket science. Unlike rocket science, plumbing requires a license!
Nope, I can't come up with any valve malfunction that can cause a vacuum. All valves have an internal valve that is opened to allow flow out to the drain line and there is no way for a vacuum to be created to reverse flow in the drain line.
An air gap is meant to prevent cross connection contamination of potable and non potable waters.
Yeah that's what I said, an air gap is a gap (read separation) of at least twice the ID of the drain line from the end of the drain line to the top of the stand pipe or sink rim. BTW, some approved air gaps are not vertical.
Click Here to learn how to correctly size or program a water softener.
He said;
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.
The tee is screwed into the top fitting of the stand pipe which seals the stand pipe which sounds to me as if it is not an air break. It will be unsealed and an air gap when he drills a few 1/4" etc. holes in the top part of the stand pipe.
Now you need to get into whether the drain water from his filter and softener is potable or non potable.
BTW, what do the other 4-5 national plumbing codes say about this? I ask because in the past here'n other where you have always said an air gap was required.
Click Here to learn how to correctly size or program a water softener.
Thanks for posting the actual rule, Tom. Good to know it meets code. I wasn't about to change mine, and wasn't suggesting he change his. But it IS good to know we are legal for future home sales.
Gary, I'm sure you know the inner workings of the valve better than I, so if it's not possible for a malfunction to suck waste water into the valve, so be it. In my case, my drain runs overhead into the sewer lines which are in the ceiling, so I know drain water lays in the tube after a cycle. I would think it would be more prone to cross contamination than a drain that only runs down hill. But I drilled the holes you mentioned, and it's a fairly good air break, IMHO, so perhaps I will be safe.
Thanks for the input!
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