vacuum breaker delete??

[gwking11]

I am now replacing like my 5th failed vacuum breaker in 3 years. makes a heck of a mess in the trailer when they fail.

Has anyone deleted these from the flush system? are they really necessary??

this seems useless to me as the hose is open the entire way.

any input accepted!

[sundancer 87]

Originally Posted by gwking11

I am now replacing like my 5th failed vacuum breaker in 3 years. makes a heck of a mess in the trailer when they fail.

Has anyone deleted these from the flush system? are they really necessary??

this seems useless to me as the hose is open the entire way.

any input accepted!

Are you calling the vacuum breaker the place where you connect the garden hose to flush the black tank?

[gwking11]

No...the vacuum breaker is actually on the inside of the wall right behind the hose connection. When they fail they spray water all over the inside of the trailer. In my trailer there is one in the half bath and one behind the connections in the front.

[sundancer 87]

Originally Posted by gwking11

No...the vacuum breaker is actually on the inside of the wall right behind the hose connection. When they fail they spray water all over the inside of the trailer. In my trailer there is one in the half bath and one behind the connections in the front.

I'm thinking it's the tank flush connection from the location description but a photo would help.

[Thom]

I'm thinking back flow preventer.

But I haven't seen one of those fail

[gwking11]

Originally Posted by Thom

I'm thinking back flow preventer.

But I haven't seen one of those fail

Is there a backflow preventer on the flush side...if so maybe that is what it is, but it is literally right at the water hose connection.

A short piece of tubing comes out of the wall to this thing, which lets air into the tubing going down to the tank. No idea why it is needed, but the dealer told me they had to replace it and couldn't delete it. If they fail, or if you turn on the water hose too slow, then it doesn't seal and water sprays out of the top of it. And, of course since I am not in the trailer when i flush, I end up with water seeping out from under all my cabinets!!

I will take a picture and post it tomorrow....

[sundancer 87]

Originally Posted by Thom

I'm thinking back flow preventer.

But I haven't seen one of those fail

Might be one of those back assward installs.

[KN5DX]

It does act as a back flow preventer and key purpose is anti-siphon device. It is set between the inlet and outlet at high point. When no water connected allows it to drain back into tank through air valve. Water connected its spring loaded valve opens, closes off air vent and flows to tank (basically acts as a 3 way valve).

The repeated failures could be to water freezing and cracking interior of valve. I use air to blow lines clear on winterizing. See picture of home brew rig. Not had any problems with them.

As to deleting the valve, just make an informed decision about its purpose. You could have black water siphoned back into fresh water line or onto you. Maybe use a hose line black flow preventer.

[Tanman]

I am confused as hell... what part of the picture are we looking for and is the picture and actual part removal?? Are the gate valves part of this plumbing behind the wall???

[sundancer 87]

Originally Posted by Tanman

I am confused as hell... what part of the picture are we looking for and is the picture and actual part removal?? Are the gate valves part of this plumbing behind the wall???

Tanman man,

I use air to blow lines clear on winterizing. See picture of home brew rig. Not had any problems with them.

[KN5DX]

This is picture of rear bathroom under sink. The black valve mounted to wall is the vacuum breaker (anti siphon valve). The hose on right is from sani flush connection outside. The hose on lower part goes to black tank #2.

[KN5DX]

This picture is of vacuum breaker behind shower access port.

Second pic is shower access port. This valve serves the forward sani flush and the main black tank.

[KN5DX]

This is picture of home made winterizer fixture. Made from CPVC, brass hose Bibb fitting, CPVC valves, and air fitting. I use blue fittings for all tools that do not use oil. Red fittings for oil operated air tools.

The air compressor regulator can be set to 40 psi and effectively blow the water from lines.

The bottom of fixture has hose barb (I took off hose other day to store for summer). Piece of poly hose then can suction from RV antifreeze bottle sitting on ground.

[dougs2]

Originally Posted by KN5DX

This is picture of rear bathroom under sink. The black valve mounted to wall is the vacuum breaker (anti siphon valve). The hose on right is from sani flush connection outside. The hose on lower part goes to black tank #2.

I had same problem with water leaking from under the rear bath sink when I used the black tank saniflush, turned out those hose clamps were never tightened from the factory, cinched them down really tight to get it sealed up and have never had a problem since.

[sundancer 87]

Several of them have been noted as being installed backwards as well as installed poorly.
This could be the reason for five failures in this one RV.

[dougs2]

Originally Posted by sundancer 87

Several of them have been noted as being installed backwards as well as installed poorly.
This could be the reason for five failures in this one RV.

Yes and as you and others have said, it's a good idea to blow compressed air through the sani flush lines, I also push rv antifreeze through them to be safe.