Dishwashe air gap outlet


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Old 04-15-16, 11:29 AM
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Dishwashe air gap outlet

OK, here's a question.
I want to install a multistage water filtration system in my kitchen. They all come with a little spout that is normally installed into a NEW hole drilled in sink top somewhere convenient.
Thing is, my kitchen is all solid granite and sinks are under the countertop style.
Means I'll have to drill a hole through an inch or so of granite plus sink plus countertop base.
I am rather not doing this.
But, I was standing there yesterday contemplating and looked at a shiny chrome cylinder next to faucet. Took cap off and it's plastic piece with a hole on the side inside. Traced it under the sink and it's a long corrugated tube going to dishwasher.
Found it's an air gap for dishwasher.
Fine with me, apparently some sort of a vent.
But see, it already has HOLE of suitable size and location for the spout - in the countertop.

Here's my question then. How crucial it is to have that air gap hole ABOVE the contertop level? As I could scoot it under the countertop and tape to its bottom, so it's still high up. Will drop the vent hole by maybe inch and half, 2 inches.
But then I have ready to use hole all done for water filter spout.
Yes, I know air gap can eventually start leaking water, but we use dishwasher maybe 3 times a year.
I am simply not sure, IF that vent hole in air gap MUST be above the dishwasher upper edge or not. Will be pretty close to it if moved under the sink.
Also, can't that air gap hose be simply routed to ABS drain pipe instead?
 
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Old 04-15-16, 05:12 PM
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Air gaps are not required by the Uniform Plumbing Code, so long as there is a properly installed high loop.

However they are required in Certain States, California is one. If required I recommend you keep the air gap.

Your DW drain is the 5/8" hose to gap, where does the other 7/8" hose go to now, disposer?
 
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Old 04-15-16, 05:28 PM
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Let me make sure we talk same thing

http://www.askmehelpdesk.com/attachm...1&d=1242773580

I have not noticed a 2nd hose connected to the air gap outlet. But I'll double check later tonight, there might be one.
So, according to the picture, there should be two hoses connected to that cylinder on the countertop?
What I have on the countertop looks like this:
http://www.build.com/imagebase/resiz...ickel-1971.jpg

In other words, I can bypass air gap and simply connect drain hose directly to the sink? No disposer, I am on septic.
 
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Old 04-15-16, 05:32 PM
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properly installed high loop.

What is that?
 
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Old 04-15-16, 05:40 PM
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OK, I got it. Simply loop drain hose all the way up to the counter bottom, secure there and run it down to sink drain. Then I can free air gap hole for my filtration system spout.

Dishwasher High Loop and Air Gap Devices - Racine Home Inspector
 
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Old 04-15-16, 05:41 PM
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There must be a loop in drain hose above the highest point water is in dishwasher. Usually someplace close to counter top.
 
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Old 04-15-16, 05:55 PM
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We are talking the same thing. The air gap definitely has 2 hoses.

In other words, I can bypass air gap and simply connect drain hose directly to the sink? No disposer, I am on septic
You cannot bypass the air gap if it is required by local plumbing code. You need to check the local code.

In your picture the larger hose goes to the garbage disposer, which is typical.
If you don't have a disposer, then the larger hose will go into a 7/8" outlet Branch Tailpiece.

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Old 04-15-16, 05:57 PM
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Or, I can bypass it if it is NOT required, right? I have buddy plumber, I'll find out from him.
 
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Old 04-15-16, 06:01 PM
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OK, it can be either high loop or air gap. Our house here before this one did NOT have air gap and passed inspection no questions.

Here's code:

Domestic dishwasher waste discharge diagrams
 
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Old 04-15-16, 06:12 PM
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You are required to have an air gap.

The Johnson Tee is not a high loop, it's actual pipes inside the walls, a separate "special" drain at a specified height.
 
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Old 04-15-16, 06:44 PM
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King County, Washington (where ukrbyk lives) REQUIRES either a standard (counter mounted) air gap OR a Johnson tee arrangement. The high loop does NOT meet requirements.

The Johnson tee is generally not recognized in other areas.

https://www.google.com/?gws_rd=ssl#q...on+tee+air+gap
 
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Old 04-15-16, 07:40 PM
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This is for members who wonder why an air gap is required in their area, and why a high loop is insufficient. This subject comes up often. Air gaps should be required everywhere.

The reason air gaps are required is because there is no way a high loop can be placed above the flood level of the sink.

The air gap must be above flood level of the sink so that sewer water cannot be siphoned back into the dishwasher. If your pipes clogged, and the sink rises to flood level with sewer water, the dishwasher will siphon the water into the tub.

Code doesn't give any exceptions for quality dishwashers that have taken precautions to prevent this.
 
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Old 04-16-16, 08:09 AM
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Thank you, Brian. Out of 3 places we , heck, 4 places we lived in here, in King County, this is the first one to actually have air gap. Just saying.
I know what I'll do.
Thank you all for insight.

Sorry, I just have to ask a stupid question. How dumb you have to be to NOT notice water backing into your sink BEFORE it reaches counter level? Add to this that dishwasher apparently must run 24/7 to run right exactly at that moment to siphon it in.
I know, it's idle question. Simply sitting here trying to picture the situation. Oh, look, sewer water is backing into the sink. Oh, let's turn dishwasher on.
 
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Old 04-16-16, 08:50 AM
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I've done research on the subject and find it interesting.
Obviously it would take a series of rare events for siphoning to happen, so it might sound overboard.

But the government is concerned for 2 reasons:
- I called the backup "sewer water", but the concern is better called raw sewage, stuff no one should be around. The backup might come all the way from the municipal sewer system.
- The government is also concerned that the raw sewage could make it's way back into the municipal water supply.

Trying to picture that situation will take awhile
 
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Old 04-16-16, 09:04 AM
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Yeah and I am on septic so government may kiss my right foot, honestly. My leach field will go bad and tanks overflow WAY BEFORE it will back into the kitchen.
As I saw it place else, not that a dishwasher police will knock on my door right after I move that air gap.
 
 

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