Backflow Valve

[droregon]

Anybody use a backflow valve on their "garden hose" to keep it "clean" when using it on the Black Tank Flush?

Lots of videos instructing to use separate hose, not fresh water hose, when attached to Black Tank Flush. If contamination is a major problem, wouldn't a simple backflow valve reduce the risk?

Don't get me wrong, I would use a separate hose, but intend to add a simple backflow valve to keep the garden hose clean too.

[halfprice]

It won't hurt any to add one but I use separate hoses always

Jerry

[Travelin' Texans]

If the original backflow device is still in place & working properly you shouldn't need any addon backflow device.

[Lt Keefer]

My Hurricane flush doesn't seem to have a back flow valve so I use the everyday garden hose for flushing the tank.

[Bob Denman]

Separate hoses... and run a bleach mixture through it after each use.

[wrapped]

Separate hose and your black tank flush should have a valve on it,usually hidden.

[droregon]

Thanks for the replies, All.

[Davidgrape]

Yup...my house water hose is white....black water rinse hose is green....in separate areas for storage too....I have a backflow on my h20 y adapter also.

[Popfla]

My "San-T-Flush" has a check valve built in, and the piping rises above the tank; the check valve is at the top. But I still use a separate hose to flush the tank. Same as this diagram, but different brand.

[Porkchop]

Unless your flush was installed after the fact by an untrained, uneducated person it has a check valve in it from the factory. Every factory. Code required.

Bill

[droregon]

So, if all the black tank flush plumbing have back flow valves built in, why the great concern about using a dedicated hose?

I can understand not using your white fresh water hose, out of abundance of caution. But any other hose would do?

[lwmcguire]

Real back flow preventers have dual valves and test ports and are required to be tested and certified annually. The little Mickey Mouse ones on the black tank rinse are simply a band aid. Usually if you have positive pressure when turning off the hose and everything works nothing happens. Many frost proof hydrants when used as the water source and turned off drain back creating a small vacuum which can exacerbate a real problem.

Isolating and separation of the two systems and hoses as many said they do just makes sense and protects you and the next person attaching a hose to the bib.

[Porkchop]

Some people are just squimish and think a separate hose will protect them better, and some people do not realize there is a backflow preventer already there. Me+not so much but I grew up drinking out of green hoses in the yard. This discussion does not pertain to what you consider 'REAL" backflow preventers. And yes they are required in a sewer flush system in an RV, same as vacuum breakers are required on outside bibs in new construction. YEMV

Bill

[ducksface]

I carry two hosez because I can and I might want to use both hoses at once. I might even want to run the black hose down a sewer outlet or push it down a rat hole. I might, if the need arises, use it to transfer fuel. I could sure use it to pour oil into some hapless guys v10 who though he could get a oil can in there, and I'm sure it'll pour antifreeze into a radiator or be cut up as emergency tie downs.

Really we have three hoses because I carry whatever the good brand of collapsing hose is, 150ft of it, on one of those cheap orange plastic extension cord reels. Used once, it was a good thing we had it.

I've been known to pull a hunk of jerky off a coyote killed cow carcass that's been sitting out for a year so it's not fear for me, it's preparedness and utility(and I'm unconvinced how a cheap backflow valve without pressure on it would stop fumes.)
I'll use two hoses.
There is no sense, nor practicality to using just one hose except in an emergency.
(one is none, two is one. Some of us live by that)

There's something called
False economy.
I think it means using just one hose.

And
This is sitting in the mod box. It will permanently install between the generator and rear wheel of the 24.1. No more hose to drag out and unroll and cuss and re-store. A slight pull and it rewinds itself. 65 feet or three feet, it won't care....
https://www.amazon.com/gp/aw/d/B003S...b_b_asin_image
I paid $69 tax included.

[Bob Denman]

Originally Posted by droregon

So, if all the black tank flush plumbing have back flow valves built in, why the great concern about using a dedicated hose?

I can understand not using your white fresh water hose, out of abundance of caution. But any other hose would do?

It may not be necessary; but is probably a pretty good idea.
Valves CAN leak...

[Popfla]

My tank flush hose has a ball valve where it connects to the RV so I can turn it on or off without having to drag my ancient bones to the hose bib several times. I leave the hose charged all the time, except if we leave the site.

I use a second hose mainly out of sheer laziness. I don't feel like disconnecting the white hose, connecting it to the tank flush, eventually disconnecting it and reconnecting it to the other connector, turning valves on and off several times, when I could spend all that time sipping a cold adult beverage and watching a football game.

[16ACE27]

Originally Posted by droregon

So, if all the black tank flush plumbing have back flow valves built in, why the great concern about using a dedicated hose?

I can understand not using your white fresh water hose, out of abundance of caution. But any other hose would do?

Because the backflow preventer for the flush is exactly the same as the backflow preventer for your city water inlet: it's a simple rubber disc check valve which can and do fail. And unlike a vacuum breaker backflush preventer, when it fails you have no idea unless there's pressure in the tank and you hear it escape when you disconnect the flush hose.

[ducksface]

I had assumed everyone would know of the
Laze factor.
One hose is far more work than needed.

https://www.amazon.com/gp/aw/d/B07R1...b_b_asin_image
These are the nicest quick fittings I've ever used. They're like handling an expensive shotgun. Beautiful work.

[Popfla]

Originally Posted by ducksface

These are the nicest quick fittings I've ever used. They're like handling an expensive shotgun. Beautiful work.

But you still have to remove the male fitting of the quick-connect when you're traveling or storing the rig so you can use the rubber/plastic covers to keep dust and critters out of your plumbing.

[ducksface]

You plug up by one of the female quick connect ends by using your normal male plug and use the quick connect.
Or, as I do with the black hose;
screw/quickconnect one end to the other so there's no hope of a leak or 'misplacing' an end in the tangle of things and it stays coiled better.