Would 0-30l/m possibly fall into the flow meter range for a tig welder flow meter ?

0.5bar or 7.5psi relief valve , maybe something off an airbrush unit ?

Just a few thoughts .

Yep Aussie !

Also look at Medical stuff – just a thought .

What is your project ?

Understanding what you are trying to achieve will help the forum members to help you ,

If you are playing with water then try places that deal in fish tanks or aquariums , also look at scuba diving gear .

Hi,

XD351 beat me to it, i was going to suggest an aquarium aerator. If it blows too much air, excess could be bled off via a pipe with some sort of relief valve. Dont know exactly how they work.

John

Hi,

I used to do the same as what you are planning to do when I worked in a factory. I hooked a pressure sensor to a tee on the air line and connected it to a data logger to measure the height of water in a tank. I originally tried to control the rate of bubble formation using a pressure reducing valve. The problem was that the flow rate varied with the depth of the liquid and I could never get a stable air flow rate.

I ended up using plant air at 110 psi through a ball valve.

Get the smallest ball valve you can find, shut it and connect between an air compressor and your tube. Put the tube into the liquid and slowly crack the ball valve open until you get the desired flow rate (bubbles/second). If the liquid level changes it shouldn't affect the flow rate as the supply pressure is so much greater than the variation in back pressure and the pressure drop change across the valve ( and hence the air flow rate) will be trivial. If you want to monitor the liquid level then put a tee in between the valve and the tube and connect it to a pressure gauge.

Trying to get a stable air flow by setting the pressure will not give stable operation.

Regards,

Alan