Valve on fresh water overflow pipe?

Richard_R

In one of those wonderful dump station conversations (ahem), a fellow RVer recommended adding a valve to the fresh water overflow pipe suggesting that if you close it you while you're trundling down the highway, you would lose a lot less water from a full tank. Seemed like a reasonable idea, you just have to remember to open it at the campsite. It's an easy enough modification, but as I was digging through my irrigation supplies to see if I had what I needed, a couple thoughts came to mind.

First, do you really lose enough water to necessitate such a thing? Second, I'd be a tiny bit concerned about expansion due to heat; i.e., would that extra pressure in the tank cause short- or long-term problems? 

Thoughts or comments are appreciated...

AndreO

What trailer and year do you have? On a 400 the overflow  pipe is well above the water tank. I doubt even one drop is lost to sloshing etc.

Richard_R

2023 TAB 400 boondock

KK1L

And when you forget to open the valve when filling...and you will...what then? I have filled fresh to overflow as a habit in my campers, but I don't know if anything gets lost enroute. I might say you could give it a try and let us know My guess is it is not worth worrying about or worse setting yourself up for a potential problem. Certainly the time spent on the experiment below is not worth the time. Unless you have a YouTube channel and need an idea for an episode.

1. fill to overflowing
2. empty and measure the volume
3. fill to overflowing
4. drive around
5. empty and measure the volume
6. subtract 2 and 5
7. report the loss

Richard_R

Thanks for the input @KK1L, but I think I'll decline on your experiment  . In fact, I've already decided to abandon the whole project... 

rfuss928

KK1L said:

And when you forget to open the valve when filling...and you will...what then? I have filled fresh to overflow as a habit in my campers, but I don't know if anything gets lost enroute. I might say you could give it a try and let us know My guess is it is not worth worrying about or worse setting yourself up for a potential problem. Certainly the time spent on the experiment below is not worth the time. Unless you have a YouTube channel and need an idea for an episode.

1. fill to overflowing
2. empty and measure the volume
3. fill to overflowing
4. drive around
5. empty and measure the volume
6. subtract 2 and 5
7. report the loss

OR

1. Fill to overflow
2. Mount GoPro camera facing overflow outlet
3. Start camera
4. Go for a ride

More and better video for your YouTube....