Plumbing/RODI question

[Wild Bob]

Hi all. I am in the middle of my annual kitchen sink stoppage and am concerned about my RO/DI unit under that sink. The wastewater saddle clamp attaches to the sink drain pipe and is located above the RO/DI unit. What are the chances that the nasty stuff - including the useless drain cleaner - back-flowed into my RODI? I don't recall seeing an anti back-flow valve anywhere on that rig. Is my concern justified? Anyone know if there is anything available to prevent this from occurring?

 

[H2OPlayar]

Hi all. I am in the middle of my annual kitchen sink stoppage and am concerned about my RO/DI unit under that sink. The wastewater saddle clamp attaches to the sink drain pipe and is located above the RO/DI unit. What are the chances that the nasty stuff - including the useless drain cleaner - back-flowed into my RODI? I don't recall seeing an anti back-flow valve anywhere on that rig. Is my concern justified? Anyone know if there is anything available to prevent this from occurring?

So long as the unit is full of water, you won't get much mixing. The last couple inches of waste water line might get some contaminants through diffusion of the molecules, but it's kind of like when you stick a straw in water, then put your finger on the other end and pull it out. It should by a hydrostatic situation for the most part.

 

[Wild Bob]

Thanks- That makes sense. Anything that made it into the waste water line will get purged once I turn on the RODI.
Time to break out the drain snake, which requires a posture I am too old to maintain.