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View Full Version : Salt resistant spring check valve out there?


Edward Smith
01/18/2009, 12:23 PM
Here's the scoop.

Got a 17g zero edge setup (its very sweet!). Had it for year.

Being more paranoid then most, I don't trust the standard check valve. Initially, I tried thy Wye valve but it would still not drop about 1 in 20 test, too nerve racking for over a grand in livestock. As a result, I made a return that reached right to the surface of the water and then redirected the flow downward so it wouldn't disturb the water surface.

This has worked great for the last year and doesn't depend on any check valves but.......the wife is tired of the return being visible in the middle of the zeroedge.

I've considered many different options and designs (thanks to you great DIY'ers at RC!) and think the best option is a spring loaded check valve.

So finally the question......any spring loaded check valves out there that will be safe in a reef aquarium?

Thanks!

coralfragger101
01/18/2009, 12:26 PM
I wouldn't trust any check valve - period.

I'm not following how it is now and what you are attempting to do. How about a little more clarification?

Edward Smith
01/18/2009, 12:32 PM
<a href=showthread.php?s=&postid=14183604#post14183604 target=_blank>Originally posted</a> by coralfragger101
I wouldn't trust any check valve - period.

I'm not following how it is now and what you are attempting to do. How about a little more clarification?

Thanks, but I just need to know if there is a spring check valve that is reef safe. Concerned about the stainless steel spring effecting water quality.

stugray
01/18/2009, 02:21 PM
I'm with coralfragger101

"I wouldn't trust any check valve - period."

We need to know more about what you are depending on the valve for.

I have found check valves are accidents waiting to happen & should never be depended upon in a reef tank.

Stu

kcress
01/18/2009, 02:21 PM
Search McMaster-Carr.


Then search out an alternative. Check valves have no place in tank systems. They are the devil's work.

coralfragger101
01/18/2009, 02:36 PM
At least tell us about what size you are looking for.

ob1thx1138
01/18/2009, 02:40 PM
I agree with most of the posters here. Check valves are typically unreliable. I work in a very large power plant and we have many check valves in high pressure high flow systems and some in lower pressure low flow systems. They ALL leak, many times they NEVER funtion at all and they are NEVER relied on to prevent flow. When we are isolating a piece of equipment for work to be done we NEVER trust a check valve to isolate the piece of equipment.

As for the stainless steel affecting your tank...well I am not to sure about that. have there been studies showing that the stainless reacts with the salt water. If that is the case then I guess most of us need to stop using pumps with stainless steel shafts.

redbj
01/18/2009, 03:55 PM
I think that having a return w/ a siphon break like you have is the most reliable way to go. I have a standard swing check in my tank and it does a pretty decent job of stopping the water going down into the sump.

fat-tony
01/18/2009, 04:13 PM
Find some posts that include pictures of tanks overflowing and destroying carpet or hardwood flooring. The fact you're safe and have had no problems she should be thankful that there's nothing that's gone wrong. I think she needs a wakeup call more than anything that you're asking for trouble by changing what's already working.

Edward Smith
01/18/2009, 04:23 PM
Thanks for all your thoughts. I'm looking for a 1/2"

If any stainless steel spring will do, then question is mute.

I was hoping to find a specific name brand that was known to hold up to salt water.

McMaster-Carr is a great place to find one, but doesn't have specific recommendations for salt water.

The reason I didn't explore the topic more is because it was pretty well hashed out (6 pages?) here a year ago with a bunch of helpful DIY'ers.

No chance of wet carpeting. If it failed, the tank would drain to sump that can absorb all the water.

Just was hoping for a brand name recommendation for a spring coil (.5in) check valve that can withstand saltwater over time.

Thanks

ob1thx1138
01/18/2009, 04:36 PM
ever thought about modifying a non spring check valve to a positive check valve using plastic components. I know it would probably take a lot of trial and error, but would be more reliable than a non spring check.

I am sure this was already discussed in the previous thread, but what if you used a small air line as a siphon break. You could keep your discharge nice and low but run the airline under the substrate and up a corner higher up in the tank.

NanoReefWanabe
01/18/2009, 06:05 PM
<a href=showthread.php?s=&postid=14185164#post14185164 target=_blank>Originally posted</a> by ob1thx1138
ever thought about modifying a non spring check valve to a positive check valve using plastic components. I know it would probably take a lot of trial and error, but would be more reliable than a non spring check.

I am sure this was already discussed in the previous thread, but what if you used a small air line as a siphon break. You could keep your discharge nice and low but run the airline under the substrate and up a corner higher up in the tank.

how would you prevent the water from shooting out the air line?

i think everyone is missing the point here with his zero edge tank, it is designed to be a look down tank, where the water surface isnt broken by anything other then the light...having plumbing sticking out of the water is kind against the whole design, so i can see her point....(even though his is more valid) i am pretty sure the tanks are designed to use check valves, and i assume that is why his sump is large enough to hold the entire volume of his tank...but coral and fish dont like that very much...even if the return only allowed half the water to drain the top corals wont like being exposed for too long...perhaps you could inline two check valves one after the other, so if one fails the other may pick up the slack, and have a true dual union ball valve above that so both checks can be serviced...

there is another soloution you could try...how about building your rockwork out of the tank a bit, creating an island, then you could still have the plumbing up and over as you have it ...but hidden below the rocks, which could be used by other land hermits or a mangrove or two...

liveforphysics
01/19/2009, 05:16 AM
The spring is not always the problem with a check valve. The sealing surfaces for the flapper (or piston, depending on the type), quickly become coated with deposits and films of crud that cause them to stick or rapidly leak during operation.

If you were to change the valve out once a month, or at least throughly clean the sealing mechanism of the valve on a regular interval, you would improve your chances. It's still a very bad idea.


My tank is also rimless, and I also didn't want any plumbing to come over the top or at the surface. You can run your siphon break externally. I ran mine in a "U" shape up the side of the tank that sits against the wall, and it's not visible this way.

Even if your tank is free standing with no walls to tuck against, you can run the siphon break along or inside the structure to hold the lighting.

That should fix the problem in a maintance free way without the need for check valves, UNLESS your tank is free standing AND has ceiling mounted lighting. In that case I would go with both a check valve and a motorized ball valve with auto spring-return, and a pressure switch or flow sensor to activate the valve to stay open during normal operation.

Best Wishes,
-Luke

BeanAnimal
01/19/2009, 06:59 AM
<a href=showthread.php?s=&postid=14183648#post14183648 target=_blank>Originally posted</a> by Edward Smith
Thanks, but I just need to know if there is a spring check valve that is reef safe. Concerned about the stainless steel spring effecting water quality.

Edward, the answer is "no" there is no "safe" check valve in your situation. I would imagine you could find one with a plastic or stainless spring that will not corrode. The bigger picture is that it does not matter.

Luke pretty much summed it up. Placing a "return tower" in the center of the tank is the easy way out. With some planning and thought, y people will never know that it contains plumbing. Build it as high as you are comfortable. If you are ok with 8" of water draining, then only build it to within 8" of the surface.

You can then use check valves (and maintain them accordingly). They will keep the tank full but if (and when) they do fail you are covered.


Bean

scottyd1119
01/19/2009, 11:14 AM
A couple people have recommended using small tubing and running it up along the edge to act as a siphon break. While this will break a siphon, it would not work in your case. To have a siphon you would need to have somewhere in your return line higher than the water level in your tank. In your case the return is always below the water line and will act like a drain, not a siphon. The return will be a drain until the water level lowers to below the opening of your return and will then stop taking water out of the tank.

I agree with Luke and Bean, your best bet is to go with as high a return as your comfortable with and use a check valve if you want, but don't rely heavily on it.

DodgeDude99
01/19/2009, 11:50 AM
look into the medical supply. there is a check valve that is used for drains (draining wounds, puss, fluids, etc) that is a clear tube with barbs at each end for hoses, and the actual check valve itself was a piece of silcone hose in the center that water pressure would force open.

think of a hose always pinched flat unless pressure went thru it. since the small diameter, i had used one of those on an old system for years and never had a failure. i had gotten it from the animal hospital i had worked at when i was a teenager.

8BALL_99
01/19/2009, 12:21 PM
I would me more worried about the check valve then the looks of a return in the top of the tank. And yes you could end up with water on the floor. Who says a check valve with a metal spring cant stick closed. Or if you do place the return very low your sump might overflow. I'm sure you would make sure the check valve wasnt' the only thing keeping the sump from flooding but still. I wouldn't trust a check valve for anything. Like others said if you do use one just make sure when it fails it won't cause a problem. But if thats the case why even use it?

ob1thx1138
01/19/2009, 01:17 PM
Sorry I was making the assumption that his return line would come up out of the bottom, climb toward the top of the tank, have a U in it and have the actual discharge near the bottom of the tank so as to not disturb the water surface. The Air line would come off the top of the U at the highest point of the return and snake back down, under the sand and up a corner to a point slightly lower than the U and turning to point down. That way once the water level dropped bellow the U and the end of the air line it would suck air and break the siphon no matter how low the actual discharge was. I also assumed all of this would be concealed by rock work. Of course if you are willing to allow several inches of water drain then you could eliminate the air line and just have a siphon break drilled into the top of the U and divert the flow away from the surface with the rock work that conceals the plumbing.

DodgeDude99
01/19/2009, 03:18 PM
the thing i was talking about is a Heimlich Chest Drain Valve.

like i said, clear tube with barbs on each end, and a silicone tube inside that stays shut unless something is going thru it.

and Ed, being that you are in the medical field....

Harry_Fish
01/19/2009, 03:38 PM
When I started setting up my new tank the reef shop guy
kept telling me I needed check valves...

I just smiled :)

If I need check valves I have serious issues with my design.

ReefEnabler
01/19/2009, 07:02 PM
Luke, how does your external siphon break work???

If it really is a small tube that runs up high..... how does the return pump not force water out of it???

I assume that wouldn't be an option for people with pressure pumps and penductors?

BruiseAndy
01/19/2009, 07:45 PM
http://catalogs.shoplocal.com/harringtonplastics/index.aspx?pagename=circularlarge&fsid=&langid=&pagenumber=161&circularid=9971

The spring is stainless, if it were 304 or 316 probably no worries but who knows. Maybe shop around and find a plastic spring to throw in there.

ob1thx1138
01/19/2009, 09:23 PM
Of course it is going to have some water flow from the siphon break, but water is going to follow the path of least resistance. Given the option of going out a large opening or a small opening most of the flow is going to go out the large opening add to that the fact that there would be increased head pressure on the smaller opening because it is higher than the larger discharge and your flow drops off even more. Now if you are running a really high pressure set up then you are going to get quite a lot of flow from that small tube, but honestly we don't run much pressure on the pumps used in this hobby and once you figure in head drop and all that the pressure at the end of that little tube is not going to be that great at all. Also you can direct that flow anywhere you like so it should not be a problem.

Edward Smith
01/30/2009, 07:24 PM
Thanks for all the help!

Motorized pvc ball valve (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120371104049&ssPageName=ADME:B:SS:US:1123)