Check-valves For Airlines

[Schmill]

So, what are peoples opinions, are all check-valves created equal, or are there some better than others?

I have been using an Elite check-valve on my 60L tank with an APS100 airpump for the past 6 months, with (as far as I can tell) no problems at all. The air pump is stood on the top of the same unit that the tank is stood on.

Now however I have been setting up my new 300L tank which is sat on a cabinet. It has an APS400 TetraTec airpump on it, and needs a check valve...

So I did it the usual way, I ran in all my airline, and then sliced the airline just after it exits from the top of the tank, and placed the checkvalve in place.
Switching on the airpump and it sounds like someone is playing a trumpet in my tank! I can only put it down to the sprung plunger in the valve vibrating in the airstream. Needless to say it is WAAAAY to noisy, (the airpump itself is noisy, and this is supposed to be a quiet one, but I just put that down to the fact it is a powerful model), but the trumpeting noise is too much....

I managed to get rid of the 'trumpet' but removing the check valve, putting a 'joint' piece into the now cut pipe, and instead placing the check valve down by the airpump itself.

However I now have a second issue, the checkvalve doesn't always 'check'. By that I mean it doesn't shut.
This is NOT good, what point is there in an check-valve, that doesn't reliably check... I want this valve to cover me for a few reasons, the first is in case of powercuts, (over which I have no control!), but the other is that I don't want to run the pump 24/7 either. I would like a few hours of 'quite time' when I shut the pump down. Obviously this is not possible at the moment with the valve not closing off.

Are there severe differences in the quality of checkvalves that I was previously unaware of?
Is there a particular type / brand that people would recommend?
I guess it could just be bad luck and I've got a duff Elite valve, but rather than think that this is a one-off 'bad valve' it now has me also worried about what happens if the one on the 60L tank fails at some point

Placing the airpump above the water level of the aquarium is not an option either.

Thanks

 

[Schmill]

Any ideas? Should I just take this one back to the shop for an exchange or should I try to get hold of a different brand? (If so which one?)

Thanks

 

[Miss Wiggle]

Yeah take it back, anything that's manufactured can be faulty and i think you've just got a duff one. I've always just used cheapy ones from DIY shops for a few pence and never had a problem.

 

[Schmill]

You can get them at DIY shops

Ah well, I'll try taking this back then, and see if another is better

 

[Miss Wiggle]

Yeah non return valve, you'll find them in the plumbing section for a few pence.

 

[Schmill]

and will they still push fit into standard 6mm airline then? I might have to go and have a nose around

 

[Schmill]

Ok, so I went to the World of Water near to where I work and bought an Interpet checkvalve, and then also took the Elite valve back to P@H and got it replaced.

The new Elite valve was stuck shut, so much so that my air pump couldn't open it, and it took me REALLY blowing it to break the seal. Placed it at the top of the tank, and..... still sounded like someone playing the trumpet, and still allowed the water to slowly seep back up the airline.
Took the Elite valve off and fitted the Interpet one, and... much better no obvious difference to the sound it makes with or without the valve fitted and also seemed to seal better.

However after an hour or so I noticed the water was still managing to creep up the airline albeit at a much slower rate.

So now I have fitted the Interpet valve at the top where the airline exits the tank, and have also fitted the Elite valve in the airline at the bottom of the cupboard where it joins to the airpump.
Over a couple of days this seems to have worked. No noise when the airpump is running, (not caused by the valves anyway!), and also seems to have stopped the back sepage, but I will be keeping a careful eye on it be assured!

 

[Truck]

there could be too much back pressure. move the check valve closer to the pump

 

[Schmill]

Sorry, which of the problems do you think the backpressure might be causing?

The 'trumpetting' noise that effected both of the Elite valves was there really bad when the valve was fitted at the top of the tank, but went away when fitted closer to the pump. However either way, without using 2 check valves I was still getting the water gradually seaping back. Using two check valves now, one a the pump, one at the top of the tank, and it 'seems' to have cured it,but I'm keeping a careful eye on it