Where to buy slip union check valves?

[danorth]

They are probably all to familiar to you reef guys, but new to me:

looks like this

 

[ThunderDog]

I bought mine from Marine Depot.
http://www.marinedepot.com/ps_searchItem.aspx?IdCategory=&SearchText=check valves

 

[funman1]

My tank had one on it when I bought it.
It slows down flow ALOT, and yes it does leak (Eventually)..

It may work fine for a month or two, but it will fail. There is just too much junk floating in our tanks that GROWS on stuff.
You might stand a better chance if you painted it black so no light could get through??

 

[jackfishy]

Try exotic, I saw some in their showcase.


Jack

 

[bobbyblank]

Lowes on calvine has them, They are not clear, but white PVC. David purchased a few while we plumed his tank.

 

[rafael13]

paradise aquarium on 47th used to have them, I haven't beem there in a while, so I'm not sure if they have them anymore

 

[dots]

Im curious, what is the application?

 

[ThunderDog]

They are designed to be a one way valve to prevent floods if you have a failure of your return or closed loop plumbing. I ended up deciding not to use them. They are prone to getting deposits of algae and calcium on the flapper valve which would keep them from sealing if needed. They do restrict flow from what I’ve read. I bought them when I first got involved in plumbing my tank but after looking at numerous tank build threads ended up just setting them aside. Marine Depot always has them available so there are probably others who would say they are a good thing and worth using.

 

[dots]

<a href=showthread.php?s=&postid=11603140#post11603140 target=_blank>Originally posted</a> by ThunderDog
They are prone to getting deposits of algae and calcium on the flapper valve which would keep them from sealing if needed.

Thats where I was going, thanks.......why buy automobile insurance if "sometimes" your not covered.

Yes, any fitting creates a minor loss due to friction.

But, if your insisting on using them consider this:

We have all seen these things in front of buildings with thier changed "steering wheels" taunting us as kids.......in reality, they are called "double" backflow preventers.

Whats the "double" in the name for? What do you think the probability of BOTH of these "double" things sticking in the open position is? Throw a pair of unions and valves on either side so they can be serviced to further lower your odds and thats almost like that Green Lizard or that White Goose type of insurance.

This way though, your going to have a wee bit more minor losses unfortunatly.

 

[danorth]

Well, thanks guys, I did get one still through Ebay. I figure I can ball valve above it and clean it if necessary. I'll still do the hole thing incase it doesn't stop the water of course. Double the safety.