The valve fits in the oxygen line nearby and let's you adjust the flow wherever you are without going back to the concentrator.

When the valve is full open (handle in line with hose) you get the flow that is set on the concentrator. Turning the handle reduces the flow until it is fully closed. The valves are modified to flow at least 1/2 liter per minute when they are closed although some concentrators have enough pressure to raise the minimum flow to 2 liters per minute.

You have to learn how far to turn handle to get your minimum flow by experimenting with it while watching the ball in the flowmeter. It isn't too touchy but not everyone will feel comfortable duplicating the same position each time. If it doesn't work out for you just send it back and we'll refund your money.

The Flow Control Valve can be attached to the end of the 2 into 1 coupling of a C-0 (see picture) or into the end of the oxygen connector on C-4 or C-7.

Some humidifiers have an alarm that squeals if pressure is too high and the combination may not work for you. If so, send it back for a refund (please tell us what humidifier caused the problem). The Aqua Pak has an alarm but doesn't squeal.

Operating instructions

1. Connect the valve somewhere in line with the oxygen tubing and open it fully by aligning the handle with the body.

2. Set the concentrator at the highest flow you expect to use.

3. Watch the flow meter as the valve is moved. There will be a delayed reaction but eventually you can see what the flow is and how far open the handle is.

4. Remember the position of the valve when the flow is steadily at the minimum

5. When the valve is closed (handle crossways) you should still hear some oxygen coming out.

Most of the control occurs when the handle is not too far from the fully open position. I'm working to come up with a valve that is just two positions, full and minimum. It's hard to do because everybody has different flow requirements and concentrators run at different pressures.