winterizing dump valves

[RV_daytrader]

after final tank dump, do you leave valves open, close valves, or close valves and pour in enough pink antifreeze to keep valve seal wet??...tia

[tenbear]

I have never given any thought to the valves. When winterizing some of the pink stuff ends up at the valve. My black tank has 2 valves, one at the tank, the other at the hose connection. The one at the hose has always remained dry. Never had a problem after 9 years.

[weathershak]

Before I went FT, When I winterized and got done running antifreeze thru the fresh water lines, down the toilet and P traps, there was enough antifreeze down there to protect the valves.

[Mocoondo]

downtheroad wrote:
This choice:
" pour in enough pink antifreeze to keep valve seal wet"

Note that with this method, you are only keeping the lip of one seal wet. With the blade closed, the remaining seal is on the other side of the blade. In the end, the lifespan of the valve will always be limited to its weakest link, in this case, the "dry" seal.

If you really want to be proactive in prolonging the life of your seals, the valve should remain open and spray some rubber protectant up in the termination valve. That is the best case scenario, and even doing this, you are only coating a very small part of the seal. I personally don't even bother.

For those who have never seen a dump valve and its seals before, here is what one looks like:



Also noteworthy is that the plastic blade is what actually keeps your "business" contained. The rubber seals exist to keep the pipes sealed. In this photo, you can see the gap between the seal and the valve:

[Dick_B]

X2 on the antifreeze in the lines.

[downtheroad]

Valves open, cap off.

Sounds like a open door critter hotel to me....rodents, bees, etc...

[Mocoondo]

Valves open, cap off.

[downtheroad]

This choice:
" pour in enough pink antifreeze to keep valve seal wet"

[harold1946]

You got it. Close the valves and add some pink stuff. One or two cups should be plenty in each. Don't forget to put a cup where there is a P-trap,sinks and shower.