check valve question

[smhslt]

I purchased a check valve and it allows airflow both ways. Does this mean it's bad?

Thanks

[Fish Folk]

As far as I know, it should not allow air both ways. My guess is that if it is truly a check valve, it is defective. 

[k0olmini]

do you mean..it doesnt matter what side you put the air on or its just leaking air?

[nabokovfan87]

On 11/22/2022 at 3:46 PM, smhslt said:

I purchased a check valve and it allows airflow both ways. Does this mean it's bad?

Yeah, that's not good.  Sometimes there is manufacturing defects so if you get a little piece of something stuck in there (in manufacturing) it won't function properly. It should have a direction indicator and only work in that direction.

[smhslt]

@k0olminiAir flows both ways, so it will produce bubbles through the air stone no matter the direction of the check valve

@nabokovfan87It is the check valve from Aquarium Co-Op, I don't see an indicator of direction. In a video I watched from Corey, he said if there is no air, switch the direction of the check valve. So out of curiosity , I tried it both ways to see what would happen, and air flows both ways.

[Biotope Biologist]

An air check valve is designed to let air pass while trapping liquids. If you are trying to reduce airflow you need a gate valve and an exhaust. 
 

air can flow both ways through a check valve. If it has no arrow to show direction make sure the rubber stopper is facing the aquarium. This is what prevents water from siphoning into your air pump. If it does have an arrow it is imperative that that arrow faces the direction the air is pumping.

Edited November 23, 2022 by Biotope Biologist

[nabokovfan87]

On 11/23/2022 at 6:24 AM, smhslt said:

@nabokovfan87It is the check valve from Aquarium Co-Op, I don't see an indicator of direction. In a video I watched from Corey, he said if there is no air, switch the direction of the check valve. So out of curiosity , I tried it both ways to see what would happen, and air flows both ways.

This is an exaggerated photo but gives you an idea. The direction is on the right, the plug shape is on the left. Mine don't let air flow backwards but they are not from ACO.

[OnlyGenusCaps]

On 11/22/2022 at 5:46 PM, smhslt said:

I purchased a check valve and it allows airflow both ways. Does this mean it's bad?

Check valves are more trouble then they are worth in my estimation.  I've never had an issue with water getting into my air pump.  Ever.  But, if you are worried about it you can simply loop the airline tubing up a bit over the water line; sort of a drip loop for electrical cords in reverse.

I have had check valves decrease airflow in annoying ways, and fail in ways that blocks airflow.  I no longer use them.  Ditch it, and never look back.  🤠