Check valve?

[bob30329]

I plumbed my chiller in the garage to my sump using flexible 1" tubing. it is pushed by a Mag 9.5. Since then, I plumbed three valves into the chiller line to do water changes.

Now I want to tap into the chiller line to push in top-off water. I was planning on using a powerhead controlled by a float valve in the sump.

Check valves are normally open, they only close when there’s a power outage. In this case, the valve needs to stay closed to prevent backflow to the top-off powerhead, but opens when the powerhead comes on to add water to the flow.

Would a regular ½" check valve do the trick or do I need to spring for a pump that doesn’t allow backflow?

The photo shows the water change setup except I used different valves & flexible pipe instead of PVC. I want to tap into the nozzle on the upper left.

[RobinsonFam1]

can you just put the check valve in backwards?
I know that sounds awfully simple but im kinda confused on the order, its one of those things i would have to put my eyes and hands on to really see.

[Geoff]

i am not a big fan of check valves in the SW environment. they get clogged very quickly. i would just use a ball valve and do it manually. you need to make sure the pressure behind the ball valve is greater than the chiller side. depending on the pressure a PH may not have enough oomph to push into the chiller. without seeing pics it is hard to tell what your head pressure is between all of the described units.

G~

[Loverotties]

I also thing something would hang it up easily like calcium,algea...etc.

[bob30329]

Originally Posted by RobinsonFam1

can you just put the check valve in backwards?

That was my thought.

There will always be pressure in the system that'll want to backflow. The other comments have me leaning towards a separate hose for topoff. maybe I can Y in a kalk doser.

But I do plan to plumb in my UV sterilizer without a pump, using a ball valve to regulate flow thru the UV. I don't really care about the dwell time in the skimmer or UV, the slower the better.

I'll post photos when I'm done.

Thanks for the input! Helps a lot!

[Doug1]

I agree with Geoff on using check valves, esp on return lines from the sump, they tend to restrict flow somewhat and are apt to fail at bad times

[yardboy]

I work in a power plant and no electricity would be produced without prodigious use of check valves. Yes, they must be maintained frequently, but then so does so much else in an aquatic marine system. They have some new ones (MArine Depot sells some) that are clear and you can visually tell when they may need servicing.

I don't use them, paranoid too, but sometimes I fantasize about not having the level in my tank drop everytime I cut the return pump power. Or when I see the saltcreep that builds up from the darn return line vent.
Oh, and there's no "backwards" in a check valve. You can install it any way you want, but remember that water will only flow one way in it, and there's a neat arrow on the valve to show you which way that will go. Actually I remember a catastrophic failure when a pump pushing 3000# pressure found a check valve installed the wrong way. It was quite dramatic. The check valve and the pump exploded.