Questions: "Back Flow" devices on water systems

[meanwhile]

We have 4 water systems (1 well / 2 springs / 2 cisterns) and they are all linked with shut-off valves to direct the water where we need it. The water systems provide water to 3 houses, 2 barns and all outside spigots (spread out between the 3 houses). Two water systems were partially in place when we bought the property, two we added but at the time, I did not know of the need for "Back Flow" devices.

I suspect that I have a Design Flaw and water is "back flowing" and thus creating problems. Question: Can I add "back flow" devices anywhere I want? Or could that potentially cause another problem?

I want to add "Back Flow" devices to:

1. Keep water from coming back out of the 2 cisterns. I would add a "Back Flow" device....where? At the pipe where it goes into the Cistern? So it cannot get sucked back out of the cistern?

2. In between the well water line and the spring lines (all waters are connected at some place and it is possible to be using all lines and have water from all sources at once -- but I suspect water is being sucked back into one cistern from the well line and that water is going from the well line to another cistern......I have to stop it.)

3. And at one Pressure Tank, in between the well water line and the spring line?

Thank you for suggestions.

If you have different pressures on the different systems, and they're all connected, then, yes, you are getting backflow. any kind of pressurized system, you can install a check valve to keep the pressure from backing up(as in water backing down the well". If I were in your situation, I would separate the systems with shut offs, so that you could turn off the well water and turn on the cistern or spring water. So that if all 4 sources fed into a common manifold, each would have a shutoff at that junction to turn off the "in", as opposed to the usual shutoff that turns off the "out"

[Bearfootfarm]

They can be put anywhere you want
One near the well would be a good idea, with additional ones coming into the cisterns as well as one for each seperate feed to different houses/systems.

A diagram of your systems would be really helpful but yes , if you have water flowing backwards you can install check valves to prevent that from happening . Depending on the layout of your systems would determine where & how many check valves are needed .

[Jenn]

(Amateur here) Most backflow are for small issues- at hose bib on side of house so if my hose is up hill and I turn it down to low flow the water- from my perhaps dirty hose- doesn't flow back in to the 'city' water system and make us sick locally or just in my house. I agree with zong. We have well water hook up and city water hook up to our house lines. Only one is ever on and I'm sure the city would demand (if we didn't already do it automatically) we shut off the line from them before turning on the well input.

Most public water systems won't permit a home to be connected to another water source . They won't take the chance of another water source contaminating their water system .

[arcticow]

Check valves AND ball or gate valves, for a failsafe.

[tyusclan]

Check valves are what you need. You can install them anywhere you don't want the water to back up. I agree with arcticow, I would probably use check valves and ball valves.

Backflow preventers are installed in public water systems between the supply and the user to prevent sewage from being drawn into the water system in the event of a pressure drop in the water supply.

[Darren]

As WV Hillbilly said unless you need a backflow preventer because you're connected to a public water system, you're better off with a check valve. Backflow preventers can run from $40 to $50 for a 3/4" up to hundreds of dollars for 2" and above.

Some states require that a certified plumber check the operation of the backflow preventer yearly if you're cross connected to a public water system. That's what the ports in the side are for.

I have a similar but less complicated system than yours with the exception I am also connected to county water. I have a backflow preventer in the county connection to prevent water from wells or a cistern from back feeding. Other wise I rely on ball valves to prevent water from going where It shouldn't.

[meanwhile]

Thank you everyone - No, we are not connected to any public water! We are WAY out in the country. So - what I need is a check valve? Or ball values? How do I know which one to use? Are they similar?

Thank you

[oneokie]

Originally Posted by meanwhile

Thank you everyone - No, we are not connected to any public water! We are WAY out in the country. So - what I need is a check valve? Or ball values? How do I know which one to use? Are they similar?

Thank you

A check valve has a spring loaded stopper in it that only allows flow in one direction. It will require positive pressure on the supply side to open, and it will not prevent siphoning in the direction of flow.

A ball valve has a handle on it that you turn 90° to open or close.

[Ross]

The only place a back flow preventer can really cause a problem is with water heaters. If you cut off their flow to the pressure tank you could build up dangerous pressure/temp in the tank with explosive forces!!!

[rambler]

Originally Posted by meanwhile

Thank you everyone - No, we are not connected to any public water! We are WAY out in the country. So - what I need is a check valve? Or ball values? How do I know which one to use? Are they similar?

Thank you

Check valves are what you want. Light spring & flap allows water to run one direction, not the other.

Ball valves are 'better' hand valves that you can use to turn things on & off yourself. Good idea to have to isolate things.

Would be really nice to see a diagram of your setup, sounds terribly complex & if something goes wrong, would be nice to have the checkvalves/ ball valves in the right place! Any way you can draw out what you got?

The one thing is your water heater. As it heats water the water expands, water flows back wards to your expansion tank. If you have 3 houses with 3 water heaters and 4 pumps supplying water pressure (holy cow!!!!) then you need to be careful not to block off those water heaters. I don't know how to help you out there without a diagram.....

--->Paul

[meanwhile]

Thanks - and yes, it is too complex. I am working on a diagram since I think I need to find a plumber to help me. But, before anyone can help, they need to understand what I have designed. I will come up with diagram next week (Dr. Appmts this week). I think I need the Check Valves but I understand your point about the hot water heaters.

I already have shut off valves at several places so that I can shut off water here/there as I choose. The problem is sucking-pressure that sucks the water back where I do not want it to go. Those are the places I need the check valves.

At the same time, I need help moving a pressure tank and also putting in a new pump (ahh yes, yet another well and pump but this one won't be connected to the big system)......

So - basically I need to find a Sober, clean, honest Plumber near us! HAHAhahahahHAHAHHAHA.......sorry.......we have already tried six plumbers and I could write a book! One of them is in Federal Prison now for various crimes some having to do with a Bear! This is true........

Thank you everyone!

[Allen W]

The well with it's electric pump and pressure tank is going to have enough pressure to overide everything else. The well system is going to need to be seperated from the rest of the system some how.

There are small expansion tanks that can be installed near the water heater if for some reason the pressure from the water heater can't expand back to your regular pressure tank .

[Harry Chickpea]

If you keep pressures in the 40 PSI range, you can use a short length of 4" PVC and a cap as a small expansion tank on the cold side of a water heater. Just put it in a protected area where it won't get whacked. If you go much over that pressure, a metal tank is safer, although more expensive.