What check valve for anti-siphon?

[I.B. Washincars]

I have an elevated RO tank and was experiencing dribbling wands, even after replacing all of the solenoid valves on the delivery pump. For a siphon break, I T'd this check valve into the line going to the bay

https://www.kleen-ritecorp.com/p-1733-kleen-rite-maxi-flow-check-valve-5000psi-14fxf-ss-hp.aspx

It seemed to work well enough until it came time for the weep system. My weep pressure is adequate for weeping, but not strong enough to make the valve "Check", so I get some dribbling. A new valve does the same thing.

Obviously, I'm using the wrong valve for this application, but don't really know what to get. Any suggestions?

 

[MEP001]

That check valve is a JE Adams which has really declined in quality control.

Have you considered using a valve at the boom as a siphon breaker?

 

[I.B. Washincars]

Have you considered using a valve at the boom as a siphon breaker?

Yes, but I would have to go into the attic to install and whenever they needed replacing. I have them in the eq. room up near the ceiling. It's much easier to deal with them there, and also to see if one is leaking.

 

[pgrzes]

It has to be at the highest point in the system.

 

[I.B. Washincars]

It has to be at the highest point in the system.

I don't understand why that is totally necessary as long as the CV is above the water level in the RO tank. I understand that the hose may empty out from the CV to the wand, but don't really see that as a big deal. Am I missing something?

 

[Jim L.]

I.B.

I’m using the same check valve as my suction breakers.

Periodically one has trouble checking a weep flow. I take the spring out and stretch it a inch or so. You might have to do this more than once…it is trial and error.

 

[MEP001]

In my experience, the check valves that have the highest cracking pressure are Parker.

https://www.kleen-ritecorp.com/p-1773-parker-14-f-x-f-check-valve.aspx

Since you're just using them inline to prevent siphon and not as an actual siphon-break, it should stop the dribble without being mounted at the highest point.

What solenoid valve are you using? I switched to these for spot-free and haven't had any problem with leaking at the bays.

https://www.dultmeier.com/products/search/6027

 

[I.B. Washincars]

To be clear, I'm having trouble with the CV itself dribbling when the bay is weeping. I don't have problems with dribbling at the wand.

I'm pretty sure the valves are Dema piston type, 416P maybe?

 

[MEP001]

So it's actually leaking weep water back into the spot-free tank? In that case the type or brand of solenoid will make no difference.

I like the Fluid Controls valves I get from Kleen-Rite, and I order the Teflon seal ones because the seal won't come off. I've had no problems with them not seating completely with a small amount of pressure on them.

https://www.kleen-ritecorp.com/p-1764-fluid-controls-check-valve-14-viton-ss-hp.aspx

It may not be strong enough to prevent the siphon dribble, but maybe one 1/2" valve on the supply line to the solenoids will stop the backflow.

 

[I.B. Washincars]

No, the CV is open to atmosphere. It checks just fine when on HP, but when weeping it dribbles out of the open CV onto the floor.

 

[Jeff_L]

Trying to envision your setup. You only have one end of the CV connected into the T right? Checks with pressure, and opens to air to allow air to escape/break the siphon. The issue is when weep is on, it's not enough pressure to close the check and you get some dribbling because the check doesn't close?

Sorry if this is obvious to everyone else, just wanted to make sure I understood the setup.

That's a delicate balance between siphon pressure and weep pressure. My initial thought is to increase your weep (I know, cost more $). But at least you could make sure that is the exact problem if it no longer dribbles. And/or put drain lines on the open side into an open tank or something to recycle the water. (Doesn't solve the problem)

 

[I.B. Washincars]

Trying to envision your setup. You only have one end of the CV connected into the T right? Checks with pressure, and opens to air to allow air to escape/break the siphon. The issue is when weep is on, it's not enough pressure to close the check and you get some dribbling because the check doesn't close?

That is exactly what is happening.

 

[Jeff_L]

Just a thought, but have you tried putting the open end of the check downward to allow gravity to assist in the closing?

 

[2Biz]

I was thinking just the opposite! If the check is horizontal, its opening just enough to draw air in at the top side and dripping a little water out the bottom side. If it was pointing down, it could still do the same thing. Pointing up, it could only draw in air. Just another thought?

 

[MEP001]

No, the CV is open to atmosphere. It checks just fine when on HP, but when weeping it dribbles out of the open CV onto the floor.

That's why I quit using the Adams valve you linked in your first post. It would seat fine on high pressure but tire cleaner/presoak would leak back into the spot-free line. You might need the Fluid Controls valve with the o-ring seal to get a 100% positive close on weep but I think that would work the way you want. You shouldn't have a problem with the o-rings coming off if there's never any flow through it.