Quote:
Originally Posted by JRTJH
No I don't "replace" it with anything. I simply take it off, put it in a box with some other things that we want to protect from freezing (hand soap dispenser, sun screen, hand lotion, etc) and leave the fittings open.
The black tank flush system is nothing more than a fitting on the outside of the RV with tubing running to that anti-siphon valve, then tubing running to the black tank sprayer head. It is NOT connected to the RV fresh water system in any way and is not connected to the gray tanks. Its "sole purpose" is to prevent sewer gas and fluids from "siphoning" back to the garden hose used to spray water into the black tank during flushing. The "danger" is that if sewer fluids were to "siphon" from the black tank, they could conceivably flow into the garden hose and cause contamination or spread of germs that are in the tank to an unsuspecting person who uses the hose for drinking purposes. So, that's the reason for the "double safety" practice of using a separate hose for black tank flushing and not using that hose to fill your fresh water tank or connect to campground water supply.
Most home garden hose faucets have an anti-siphon feature to prevent the effluent from your black tank from entering the house (or campground) water system, but it could enter the hose and cause contamination that way.
So, after all this "windy rubbish" I guess what I'm trying to say is that it does have a purpose (although it probalby wouldn't happen anyway) in the system. And when we remove it, we just leave the fittings open until next year and reinstall the valve as a part of the "de-winterization" process.
As for turning on the water gradually when using the black tank flush, some here have suggested (and I also follow the advice) that you turn on your water supply very slowly when using the black tank flush. There is a valve in there that snaps open when water is turned on. If you turn it on rapidly, the valve snaps open hard, turn it on slowly and the valve snaps open softly. The easier you "snap" that valve, the longer it will last before it snaps (breaks) the seat it's in and starts leaking.....
Hope that helps a little  |
Yes I understand now. I am not ignorant lol, rest assured. Since you opened my eyes to this I have read a number of forums on this. And found my fitting under the bathroom sink. Forgive me if you already answered this, I just want to be clear with all of this. So instead of using a pump to pump anti freeze into the black flush fitting, you just simply remove the anti siphon fitting so it does not freeze, correct?
I remember a few years ago, I had to install something similar on my auto lawn sprinklers as per code. It was not a big deal to do and as you said the dirty water contaminating the fresh water would probably never happen. But why not be sure.
I really do appreciate all of the help. I apologize if I am being repeat active. However, sometimes it is hard to get the picture someone is drawing when typing on a forum. Thank you for your patience, truly.