# Don't get this



## Gramazing (Mar 6, 2010)

I bought 2 of these check valves from Ebay:

http://cgi.ebay.com/DAZS-One-Way-Aq...ltDomain_0&hash=item2558391fb3#ht_4239wt_1008

but they don't work, they're so tight you can hardly blow through them. No big deal for me, they were only a couple of bucks and I got them with a bigger order.


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## darkoon (Jun 7, 2010)

there is probably a cracking pressure, if so it will be hard for you to blow through it.


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## JeffyFunk (Apr 6, 2006)

Gramazing said:


> I bought 2 of these check valves from Ebay:
> 
> http://cgi.ebay.com/DAZS-One-Way-Aq...ltDomain_0&hash=item2558391fb3#ht_4239wt_1008
> 
> but they don't work, they're so tight you can hardly blow through them. No big deal for me, they were only a couple of bucks and I got them with a bigger order.


As Darkoon said, you really can't generate a lot of pressure with your lungs. I'd try them out anyways. Besides, one can't blow through glass diffusors either and yet we use them all the time (at least Amani does... lol).


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## Gramazing (Mar 6, 2010)

JeffyFunk said:


> As Darkoon said, you really can't generate a lot of pressure with your lungs. I'd try them out anyways. Besides, one can't blow through glass diffusors either and yet we use them all the time (at least Amani does... lol).


 Huh, I didn't know that. I thought I could get at least 10 psi with my old lungs


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## Zapins (Jul 28, 2004)

Nope, human lungs can generate up to 2.8 psi according to google.


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## Gramazing (Mar 6, 2010)

Well bugger me, I never knew that. I didn't realize we humans were so fragile.


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## neilshieh (Jun 24, 2010)

as bill nye likes to say "NOW YOU KNOW!" and that's typical hong kong stuff... cheap stuff manufactured from china


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## Gramazing (Mar 6, 2010)

Hmmmm, so maybe I should get a decent check valve. Would the brass ones from the LFS work?


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## majstor76 (Feb 11, 2010)

Gramazing said:


> Hmmmm, so maybe I should get a decent check valve. Would the brass ones from the LFS work?


I have these

http://cgi.ebay.com/5pcs-x-Plastic-...349?pt=LH_DefaultDomain_0&hash=item3a59f0fb3d

and these

http://cgi.ebay.com/STAINLESS-STEEL...851?pt=LH_DefaultDomain_0&hash=item3a50d08c4b

and work ok. Plastic one i have on fertilizing setup and second stage co2, and brass ones on last line of defence on tank co2


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## Gramazing (Mar 6, 2010)

majstor76 said:


> I have these
> 
> http://cgi.ebay.com/5pcs-x-Plastic-...349?pt=LH_DefaultDomain_0&hash=item3a59f0fb3d
> 
> ...


I got a couple from my LFS last weekend and they look exactly like your stainless steel one, so I am using that. Its crack pressure was a less than the one that started this thread but more than the plastic ones for air. So I'm quite happy with that.


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## random_alias (Nov 7, 2005)

Human lungs can create more negative pressure than positive pressure. Instead of blowing on the input end of the check valve, try sucking on the output end.


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## NickWayn (Oct 5, 2010)

Good share. 
I won't get them on Ebay as I'm an Ebay member too.
Have fun


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