Fresh Water / Black Tank Flush Mod

[youroo]

Originally Posted by emm-dee

How is this vacuum condition created. Even if you removed the charcoal valve and put a vacuum cleaner hose on the inlet all you'll get is smelly air.

What and where is this "Charcoal Valve" you speak of? Youroo!!

[JP Camper]

Some water in the fresh tank and all you need to do is switch on the pump while rinsing the BLack Tank. Quick connects make it simple which you already have.

[DouglasReid]

I WILL NOT use even the same hose to flush my black water tank that I hook up to the camper for freshwater!

I have Y connector at the water supply. One side goes to my filter and fresh water supply. The other side, with a backflow preventer can be used to wash my truck or to flush the black water tank, etc., but NEVER use the same equipment for both!

[Dwilcox]

The vacuum breaker on the Black flush system is not spring loaded. It can be held open by back pressure. If you forget that you're flushing and water comes off of your roof you will now have a back pressure condition, if the hose gets disconnected black water will run into the hose. As a plumber for the last 30 plus years keeping black water and fresh water separated as been my main job I would never use my drinking water hose to flush my black tank.

[emm-dee]

Originally Posted by Dwilcox

The vacuum breaker on the Black flush system is not spring loaded. It can be held open by back pressure. If you forget that you're flushing and water comes off of your roof you will now have a back pressure condition, if the hose gets disconnected black water will run into the hose. As a plumber for the last 30 plus years keeping black water and fresh water separated as been my main job I would never use my drinking water hose to flush my black tank.

The mfgr specs for the valve in my system specifically says it is equipped with springs. Here it is:

"
Series LF7R Lead Free* Dual Check Valves prevent the reverse flow of polluted water from entering into the drinking water supply at the service entrance or at individual outlets. It consists of a Lead Free* cast copper silicon alloy body construction, with two compact replaceable plastic check modules, and stainless steel springs. Series LF7R is designed for non-health hazard residential water system containment, continuous pressure applications. It is installed immediately downstream of the residential water meter, in a vertical or horizontal position. Check with local inspection authorities for installation requirements. Minimum Working Pressure: 10psi (69 kPa) Maximum Working Pressure: 175psi (12 bar).

[Dwilcox]

You have what's known as a double check valve which is spring loaded most have an atmospheric vacuum breaker up underneath one of the sinks completely different animals. Mine has the atmospheric vacuum breaker no spring.

[rockfordroo]

Originally Posted by emm-dee

The mfgr specs for the valve in my system specifically says it is equipped with springs. Here it is:

"
Series LF7R Lead Free* Dual Check Valves prevent the reverse flow of polluted water from entering into the drinking water supply at the service entrance or at individual outlets. It consists of a Lead Free* cast copper silicon alloy body construction, with two compact replaceable plastic check modules, and stainless steel springs. Series LF7R is designed for non-health hazard residential water system containment, continuous pressure applications. It is installed immediately downstream of the residential water meter, in a vertical or horizontal position. Check with local inspection authorities for installation requirements. Minimum Working Pressure: 10psi (69 kPa) Maximum Working Pressure: 175psi (12 bar).

Originally Posted by Dwilcox

You have what's known as a double check valve which is spring loaded most have an atmospheric vacuum breaker up underneath one of the sinks completely different animals. Mine has the atmospheric vacuum breaker no spring.

X2 Most of us have one of these:


No springs.

https://www.amazon.com/JR-Products-5.../dp/B0095TD5S6

[CZNEDY]

All I can say is "if the RV industry thought this was a good idea, they would offer it as an option".

[spock123]

Since I don't use the outside shower I hook the shower hose to the black water tank flush. I did install a backflow preventer, when cleaning out black tank I can use hot water which gets everything loose.

[MtnGuy]

I am intrigued by the OPs innovative solution to his problem, but like others, I would be a bit concerned about contamination if the black tank flush back flow preventer were to ever fail.

Originally Posted by emm-dee

I made a quick connect hose that plugs into the outside water outlet. Turn the handles on and activate the flush.

I do similar to what emm-dee does. My SOB camper came with a Nautilus water panel....maybe the same Nautilus that the OP showed in his photo. I make sure that I have good pressure, either from the on-board water pump from the fresh water tank, or city hookup pressure. I will install the shower hose, run water through that (again checking for pressure), then hook up to my black tank flush and let it happen........but ALWAYS with the black tank dump valve open.......it is too easy to walk away and forget about things. I also make sure the missus is not using water inside the camper, just as a precaution so there would be no loss of water pressure. After flushing the black tank, I immediately unhook the shower line, and again run some water to the ground. As an added bonus to this method, I can also use warm water.

This ol' boy is a germaphobe. If there were more than a slight possibility of contamination, I would not flush my tank this way. I have more of a concern with hooking up to a camp site fresh water hydrant, and the last person there unhooking his black tank flush water hose without washing his hands after dumping his tanks.

[hikerjohn7]

Originally Posted by Charles.maine

So for a little over a year now my biggest grip about hooking up services to my fifth wheel is when I have to swap between fresh water and tank flush. For example we pull into our spot late evening and we hook up the hose to the black tank flush (just to get some water in there) and without fail within a matter of seconds I hear a voice from inside. "If you would hook up the water I could start on dinner!!" So I finish putting water in the tank and then swap the water hose over to the fresh side. Everything is fine until it comes time to empty the black tank again. Without fail I always see an opportunity to do it while someone is in the shower or while she is washing dishes. Again that will not work. Or when we are packing up to leave and I want to flush the tanks and I hear that voice again, "I need water to finish these dishes/clean up etc."

So I had this idea. I actually did it several months ago with the use of water hose tees and elbows. However it was not lined up perfect and was very difficult to maneuver. So finally today I ran into the hardware store and picked up a few things and here is what I came up with.

Both sides have shut off valves and there is a quick connect at the bottom. I hooked everything up and no leaks!! The boy is super excited about the quick connect. As he is usually the one handling the water hose.

** Not really sure why the pics uploaded sideways. That is weird. **

I have one question. If you shut the little gate valve off to fresh water intake, does create a vacuum in the fresh water tank when you draw water from that tank using the water pump?

[rockfordroo]

Originally Posted by hikerjohn7

I have one question. If you shut the little gate valve off to fresh water intake, does create a vacuum in the fresh water tank when you draw water from that tank using the water pump?

Fresh water tanks have their own vents. Will not pull a vacuum.

UNLESS - some people have problems with water siphoning out of their vent lines and have added a valve to the vent to prevent that. If they forget to open their vent valve they can pull a vacuum on the tank.

[bubbles]

Originally Posted by Dwilcox

You have what's known as a double check valve which is spring loaded most have an atmospheric vacuum breaker up underneath one of the sinks completely different animals. Mine has the atmospheric vacuum breaker no spring.

Your Forestriver installed black tank flush valve is the same. The vacuum break is on the input side of the valve (allows shut off of input side when pressure is removed) and the backflow spring plunger (check valve) is on the output side of the valve. The spring loaded plunger shut off is loaded to the closed input port (install the valve backwards and there is no flow through the valve). The backflow preventer will not allow any syphoning etc. from the black tank. Much a do about nothing.