REALLY COOL!!!

doch · #1 02-08-2005, 06:14 PM

Out of curiosity, not to mention a little bit of 'cover my butt' has anyone ever had any problems with inline check valves failing on their return lines? I would like to get a return line coming in around the bottom of my tank to get a good amount of flow going through my rocks, but am worried that if the power goes out the checks may fail... or even just leak through enough over say a 12 hour shift to flood my place

. Somewhere along the way I have heard that checks can't be fully trusted... is this true? If so is there a brand or style that is least likely to have me end up with a very large bill? What about a redundant system of 2 in-lines?

muck · #2 02-08-2005, 06:26 PM

Quote:

Originally Posted by doch

HAHA! Tricked you:

??

Why not just drill the tank for a closed loop with the return near or in the bottom of the tank. No worries about it failing that way.

Delphinus · #3 02-08-2005, 06:34 PM

I'm not a real big advocate of check valves as a fail-safe mechanism.

In my experience, check valves can place enough back pressure on the pump to cause a noticeable loss of flow. Further, I think it is a question of "when" not "if" it will fail. All our plumbing, the pipes get coated with a slime over time, that will eventually cause the seal to fail in a check valve.

Thus the only way to keep check valves is to routinely clean them out. Thus it's another maintenance chore to keep on top of, and further since it tends to be an "invisible" task (you don't "see" that the check valve is dirty unless you look inside), human nature being what it is, I think the risk is that it will tend to be ignored at some point or other.

Depending on how you have your plumbing, there are ways around having to need a check valve to prevent overflowing your sump.

The first method is size your sump to accomodate all the extra water that drains into it in a power fail scenario.

Along those lines, also make sure your returns are near the surface of the display tank(s) so that the tank(s) don't empty beyond a couple inches off the top in a power fail scenario. Sounds like common sense, but you'd be surprised how many people put sump returns down near the bottom of the tank.

(In that situation, you're completely reliant on the check valve, and it "must not fail." But there's no way to guarantee this: by cleaning the best you are doing is "hedging your bets." How comfortable are you with risk?)

The last idea I want to share is that if you have your sump return lines come "up and over" the tank wall, if you drill a few holes in the pipe near the surface, these will serve as siphon breaks. As soon as they suck air in a power failure, the siphon is broken. This idea isn't foolproof, nothing really is, but at least you can spot at-a-glance if the holes are clogged and clean them out with a minimum of fuss.

Just my $0.02. HTH.

Coralquay · #4 02-08-2005, 07:16 PM

Good Lord Tony wrote a novel again....

Delphinus · #5 02-08-2005, 07:17 PM

Uh ... Welcome to Canreef. (I think.)

AJ_77 · #6 02-08-2005, 08:28 PM

Quote:

Originally Posted by Coralquay

Good Lord Tony wrote a novel again....

One post and you seem to have a grip on the place...

You go, Tony!!

Chin_Lee · #7 02-08-2005, 08:50 PM

do not rely on check valves. they will collect gunk and are considered very unreliable in our hobby. many stories of flooding when relying on this method.

monza · #8 02-08-2005, 10:19 PM

Never used a check valve, but I hear if you replace them once a year they can work 'most" of the time.
Dave

danny zubot · #9 02-08-2005, 10:36 PM

To solve your problem. Get rid of the check valve for starters, they do reduce your flow as stated above. You can drill a 1/8 or 1/4 inch hole near the top of the return tube/pipe just under the water. When the power goes out and the level drops by an inch the siphone will break because of that hole.

Nemo · #10 02-09-2005, 06:24 AM

I run check valves in my system.

1. clean them every time you do a water change, they have built in unions, take the ball out and wipe it off and wipe out the seat.

2. they do not reduce the flow, the check valve is a lot larger than the pipe size it conects to. This is to allow ( in my case) a full 3/4" of flow around the ball, so the 3/4" line is always full.

3. If you ever decide you do not want the check valve in your system, take the union apart remove the ball and what you have left is an expensive union.

4. you can always decide to drill your return pipe in the tank at a latter date, but you can not decide to un drill a hole.

Robert