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43.841677 , -79.086692

Ok, here's the scoop. I have a combined 2600 gallons of water storage as seen here:

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=127264

The water level in the main tank will be up to 5' higher than my pump and sprinkler heads. This will mean after my pump turns off the rest of the water will siphon out of the tanks. Its not just as simple as closing a valve because I want this system to be automated. I was going to use a "master" valve on the discharge side of the pump and some one else said to forget the master valve and just install a vacuum breaker on the discharge side 6" higher than the highest level of the pump. I dont have a clue how vacuum breakers work but i need the most reliable method. Dont want 2600 gallons siphoning out when im not home.
Any advise would be greatly appreciated.

Regards,

Chris

3/29/2010 12:51:16 PM

Western NY

Tanks------------Check valve-------pump w/ pressure tank------then one of these:

http://www.orbitirrigation.com/products/Timers/01/

3/29/2010 1:51:09 PM

West Chazy,N.Y.

you will need to add a check valve !

3/29/2010 7:32:27 PM

43.841677 , -79.086692

Thanks for the reply guys. I must have described my application wrong. A check valve does nothing for me. I am not worried about the water running back into my tank. I am worried about the head pressure causing a siphon when the pump is off and draining my tank into the patch.

3/29/2010 7:44:01 PM

Back Yard

Hi Chris,
The vacuum breaker on the discharge side of the pump is correct. It will need to be 6 inches higher than the highest level of water expected in your tanks.

With the pump off (static state) the water level in the pipe AFTER the pump, will be at the highest level of your tank supply water. With the vacuum breaker at 6" above this level, you will not have water reaching the vacuum breaker so you will not lose any water.

When the pump turns on, the water from the tank is pressurized on the dicharge side piping and will close the valve on the vacuum breaker and allow water to flow through to your end use. Pump off - returns to first static state.

3/29/2010 10:14:57 PM

43.841677 , -79.086692

Thanks a lot 1tonorange1. I have a cross section view of the vacuum breaker and could not get it in my head how it would work.

3/30/2010 8:16:54 AM

43.841677 , -79.086692

1tonorange1, Is there any chance water can come out the air vent in the vacuum breaker??? Just wondering because this will be directly over the pump, electrical.
Should i run a elbow off the pump to get the vacuum breaker away from it?

Cheers.

3/30/2010 8:22:04 AM

Western NY

chris, the check valve would be needed if you had a pressure tank setup so that the water does not flow back into your big tanks. The valve timer out in the garden is what stops the water on that end. That's my current setup

Vacuum breaker would also work.

3/30/2010 8:26:50 AM

Back Yard

There will be a need to relocate the AVB to a safe area for this reason. It can be a far away as you feel is safe, but the elevation must be maintained. The set up should be:

Gravity feed to tanks from roof drains -
Tanks connected by piping -
Pump suction connected to this manifold -
AVB on discharge side of pump 6 inches above highest elevation of water in the tanks -

If you are not pressurizing the tanks, an AVB will do what you are describing.

3/30/2010 3:20:11 PM

Back Yard

Andy is correct. If you are using the pump to supply the pressure for the irrigation and NOT using the bladder tank system to maintain pressure, this will work to drain the tanks and irrigate. This is what I have at home.

3/30/2010 3:26:30 PM

43.841677 , -79.086692

Thanks everyone!!!
My pump is in my shed so what I will do is poke a hole thru to the outside and have the AVB outside. Then poke another hole and have the line go back in so my manifolds and valves can be inside.

Do the AVB leak every time they start up? Or just when they fail?

3/31/2010 8:15:49 AM