View Full Version : check valve

06/20/2017, 02:32 PM
I need to add a check valve on my ATO 3155. I have a 1/4" John Guest that I could add. It has a 0.3 psi cracking pressure. Would the pump in this system be able to open the check valve?

06/20/2017, 02:40 PM
Is it feeding a kalkwasser mixer? Short of that I would just leave an air gap as a check valve can fail. The check valve we use for our kalk dispenser has a .5 psi cracking pressure so that should work.

06/20/2017, 03:05 PM
Yes, I am feeding a kalkwasser mixer. They are both on the same level and seek each others level.

06/21/2017, 05:45 AM
Well, the advertised cracking pressure for the John Guest check valve must be wrong. Installed the valve with the correct flow and the pump would not open it. I ordered the Tunze valve from AS. Will let you know how that one works.

06/22/2017, 03:13 PM
Install the Tunze check valve and worked great. Went ahead and adjusted the controller pot to full because of the added restriction to the pump.

06/23/2017, 08:34 AM
Just be sure to place the check valve above the reactor, that check valve is made in Minnesota and is all kalk resistant materials, it is the best we have found for the job, but what can happen is if powder gets back into it, it will jam open, elevating it helps prevent that as with the lower cracking pressure the spring is not very strong and it closes slowly so some water goes back for less than a second before it closes. If that happens, use a syringe and flush it with vinegar and it should work again.

06/23/2017, 04:12 PM
Thanks Roger. I installed it about 6 inch's above the inlet to the reactor vertically. So far so good.