1968 Travel Queen Resto Mod - 8. Fresh Water
This Part 8. Fresh Water, begins at a stage in our game of rebuilding the left sidewall of the camper. It is here on that side where we run into the utility connections, much of which are fresh water ...
Forum Discussion
Ticki2 I think your air-gap thoughts on plumbing codes are quite correct in many - especially residential or commercial - applications and are probably addressed throughout the national plumbing code. However, I am thinking it doesn't apply in this situation. I accept I may be wrong and would like to hear definitively, but here's my logic.
Normal RV plumbing standards place the city water fill (with check valve right at the fill fixture) onto the RV's cold water plumbing. Immediately after the check valve is a "shared" city water/fresh water tank "water supply". If the fresh water tank is contaminated, that water supply plumbed right up to and right at the city water check valve point, is potentially contaminated. There is no air-gap right there.
Should the city water fixture check valve fail, and should the city water supply stop, creating a potential suction from your contaminated fresh water tank supply and be pulled into your home or the RV Park's potable water supply, there is no air gap to prevent that action.
And the Anderson device you linked to does just what I'm describing without an air gap.
I believe air-gaps are important and have their place; I just don't think it applies in this case because of the check-valve.
One reason I don't want an air-gap at the fresh water tank fill under the cab-over step is because I'd prefer that whole area to be free of "splash" potential. For that reason I would be hesitant to fill through an access hatch with a bucket. However, I like the hatch idea just for added functionality at times when it becomes important to fill without a hose.
Normal RV plumbing standards place the city water fill (with check valve right at the fill fixture) onto the RV's cold water plumbing. Immediately after the check valve is a "shared" city water/fresh water tank "water supply". If the fresh water tank is contaminated, that water supply plumbed right up to and right at the city water check valve point, is potentially contaminated. There is no air-gap right there.
Should the city water fixture check valve fail, and should the city water supply stop, creating a potential suction from your contaminated fresh water tank supply and be pulled into your home or the RV Park's potable water supply, there is no air gap to prevent that action.
And the Anderson device you linked to does just what I'm describing without an air gap.
I believe air-gaps are important and have their place; I just don't think it applies in this case because of the check-valve.
One reason I don't want an air-gap at the fresh water tank fill under the cab-over step is because I'd prefer that whole area to be free of "splash" potential. For that reason I would be hesitant to fill through an access hatch with a bucket. However, I like the hatch idea just for added functionality at times when it becomes important to fill without a hose.