High Loop In Black Tank Flushing Circuit?

[Gordon1152]

With all of the expertise out there, I'm sure that someone can give me a good answer as to why the coach manufacturer would put a high loop in the tank flushing circuit?

I'm redoing the wet bay and what to cut out as many extraneous hoses or extra length of hoses that I can ...

[SuperD]

The loop is to prevent siphoning when you take the cap off to attach a water hose, suggest you leave it there to avoid a potential mess!

[Gordon1152]

Wouldn't a check valve do the same thing / work as well?

[SuperD]

Originally Posted by Gordon1152

Wouldn't a check valve do the same thing / work as well?

Probably, but that's how Thor does it. If it ain't broke, don't fix it!

[Gordon1152]

Copy that ... Thanks! I guess it's a question of how you define "broke" ... They use 20 feet of hose to do what a check valve will do and I am all about eliminating unnecessary runs like that ...

[16ACE27]

All aftermarket flushers use a check valve.

[Gordon1152]

Understood ... Thanks! I'm also finding out that the high loop approach is not without its' own pitfalls (i.e. break and leak all over the inside / living space of your RV) ... I think I'll head the check valve route and save on unnecessary headaches and pipe runs ...

[Porkchop]

BOTH are required by building codes because you are directly tying potable and black water together.
So you are just willy nilly cutting out anything you don't think needs to be there? Sounds like a real plan to me. Do you really think the manufactures would put 1" more in than was required by code?
Make sure you keep posting as your project goes along. I can't wait to see what is next.

Bill

[Gordon1152]

Don't care much for your "willy nilly" comment, but the rest of it I'll take ... I was just surprised to see that they took a fixture on the driver's side and ran tubing all the way to the passenger side outside wall to accomplish what a check valve would but I understand your code perspective ...

Thankfully being an owner and not a manufacturer, I can do whatever pleases me and neat, clean, functional and effective pleases me ... but not at the sake of sound engineering logic of course ...

[SuperD]

I would double check to see if there is actually a check valve installed.

[Gordon1152]

Copy that ...

[scubes3]

Check valves can clog or jam open (they are mechanical). A anti-siphon loop shouldn't. KISS (Keep It Simple Stupid) philosophy.

[Travelin' Texans]

May want to track that "high loop" to make sure there's not an anti siphon valve at the high point in the loop. Mine has the valve hidden up behind the bathroom sink. IMHO that's a few wasted feet of pipe I'd leave as you found it.
If I were get real energetic to do what you're doing, my 1st step would be to build a water manifold for hot/cold so I could quickly shut either hot/cold off to every fixture individually from 1 handy location, which would most likely require more tubing.

[SuperD]

Originally Posted by Travelin' Texans

May want to track that "high loop" to make sure there's not an anti siphon valve at the high point in the loop. Mine has the valve hidden up behind the bathroom sink. IMHO that's a few wasted feet of pipe I'd leave as you found it.
If I were get real energetic to do what you're doing, my 1st step would be to build a water manifold for hot/cold so I could quickly shut either hot/cold off to every fixture individually from 1 handy location, which would most likely require more tubing.

You wouldn’t have to build a manifold, you can buy one, it’s a Manibloc manifold made for pex tubing. Maniblocs come in several different sizes with more or less ports, I have one in my house.

[Gordon1152]

All great input ... Thanks Guys!

p.s. Manibloc is already part of the plan ...

[Huck]

This is a little bit off topic, but has everything to do with plumbing. I have a Challenger 37LX, and the water supply to the toilet in my rear bathroom has started leaking where the blue pex tube connects to the 90 degree elbow. Since you are talking about redoing the plumbing in your whole coach, I figured you might know how I can tighten or replace that fitting. Do I need a special tool, or can I get it tightened with pliers, or even replace that clamp with an automotive screw type clamp?

[Travelin' Texans]

There at least 2 kinds of pex clamps; crimp which has a small loop sticking out somewhere on it which requires a special tool (sold at most home improvement stores) to tighten it & the same tool will work for all sizes of clamps. The other is a band clamp which just a band compressed on the pipe, also requires a special tool for each size of band. Both types a very difficult to remove without damage to the pex. My rv has the crimp fittings so I bought the tool & went through & tightened all the clamps I could get to, that's most likely your easiest fix, but not necessarily the cheapest.

[Laco]

I had a flush valve added, when I bought the Gemini. I am going to guess since it did not come factory equipped with a black tank flush, I have no high loop. Since every time I flush the black tank, every time I dump it, I would guess all that high pressure water would tend to keep that valve clear. So far no problems or issues.

[Huck]

Originally Posted by Travelin' Texans

There at least 2 kinds of pex clamps; crimp which has a small loop sticking out somewhere on it which requires a special tool (sold at most home improvement stores) to tighten it & the same tool will work for all sizes of clamps. The other is a band clamp which just a band compressed on the pipe, also requires a special tool for each size of band. Both types a very difficult to remove without damage to the pex. My rv has the crimp fittings so I bought the tool & went through & tightened all the clamps I could get to, that's most likely your easiest fix, but not necessarily the cheapest.

Thanks! I believe mine is the loop kind, so I will head to Home Depot to try to find that tool.

[ctpres]

On my to-do project list is a gradual R/R all pex plastic fittings with metal. The id on metal fittings is much larger.