sjsmithjr said:
Not to add to the debate, but the last dishwasher I installed had the discharge hose routed "high loop" against the case by the manufacturer. With this configuration, would there be any negative effects to high looping again under the sink or using an air gap?
Still learning somthing new everyday,
Sam
Not at all. The Air Gap provides the "break" to the free atmosphere that prevents the continuation of fluids/contaminates back to the dishwasher.
A perfect way to simulate a high loop; take a garden hose over the edge of a swimming pool. Once you have continuous flow the reversal of water out of the pool mimics the same as a high loop on a dishwasher.
To Cass,
I know that in Ohio that Air Gaps are not required but even though that is true my customers know that I will not install a dishwasher without one. I explain what the cause and effect is, they normally recount an event in time where the dishwasher filled with wastewater when the kitchen sink clogged.
My initial instruction as a backflow tester along with the years of involvement with the local cross-connection prevention program in my area has taught me a great deal of "what ifs" and "what can" happen if the right situation poses itself. I left many a meetings scratching my head and ass wandering how could it be. But, if you take the time and research the many case histories of cross-connections.....it's all there to see for anyone who wants to explore it.
So that is why I get involved in conversations like these because in most but merely all commercial applications
in every state there are Air Gaps used in many types of applications......including down to your local restaurant with the dishtank. That's why sink faucet spouts don't hang down below the flood level rim of the fixture it serves.
That is why a T&S sprayer is spring loaded and relaxes above the flood level rim when not in use. We afford this protection in our restaurants, no reason why it cannot be implicated down the line to residential. Are the odds less likely? Sure it is. Does it mean the idea is faulted for not using it? Absolutely not.
Just yesterday, sunday, a customer calls me to rehook up the plumbing to a new sink so they can use their kitchen till their countertops come in. Sure enough, I get there and this guy has already hooked to the dishwasher discharge to the garbage disposal. Here's my exact words, verbatim, "Better you than me, in the state of Kentucky you cannot directly tie a dishwasher to the garbage disposal without proper protection. THEN the wife chimes in after I give the facts of why it shouldn't be and what we expect of that dishwasher once it is finished running and produces clean and sterile dishes. She says that when the kitchen sink backs up when running the garbage disposal the dishwasher has about 2 inches of nasty water with food particles in it.
I rest my case. That's proof of the reversal of flow. And this guy initially had no intention of hooking that Air Gap back up because like most, he doesn't think it's needed as it has no bells and whistles like most items in plumbing. I won't be there for the countertop replacement but if he puts that Air Gap in like it's required in his state, and if I fully explained what can possibly happen to his family and children as a result of drainage reentering the dishwasher, I believe I've done my job as a licensed plumber educating the customer of why it is important.
That attitude and instruction lands me a ton of work in my area. Information seekers really like someone who is willing to explain all things considered. I have to work in Ward's Corner again this week, have to install a primary and secondary battery back up sump pump. This guy also wants a kitchen sink with dishwasher installed. I've already implied that even though it isn't code, I will not do the install without that device.
Do you think the plumbing inspectors would fail an install with that device installed, even though it isn't required? Of course not. They know that they can drive down the street to a restaurant or Kwik-E-Mart and see that device readily in use, protecting from the reversal of flow.
I know you have a backflow/cross-connection program in your area. It does not cost that much....you'll know the ins and outs of all the backflow devices made and the background knowledge opens up a whole other side to plumbing that most don't know about. I am so glad I got this knowledge back when I had the time to invest. I look forward to every year to the meetings because they are just that interesting to hear of the developing remedies and products/technology to provide safety to all the devices in plumbing that we use every day.
I'm sure glad I chose backflow over medical gas certification when I was a union service plumber; I would not be using the med gas certification for anything right now or in the past 7 years.
