Filling your own oxygen cylinders can save you a significant amount of money and headaches: Cylinders can be filled for less than one dollar, and you don’t have to wait for suppliers or worry about missing cylinders. However, many people think filling is complicated and systems are expensive. Here’s some good news (for a change!) – Filling is easy and a lot less expensive than you think. 

How Does It Work?

When gas contained in a cylinder at high pressure is allowed to flow to another cylinder containing gas at a lower pressure, the pressures will equalize to a value somewhere between the two initial pressures. So, with a gas to gas system, the high pressure supply tanks have a higher pressure than the empty cylinders that are to be filled. A filler opens the first supply tank, allows the pressure in the two to equalize, then closes the first supply tank. The filler then opens the second cylinder, and allows it to equalize pressure. This continues down the bank of cylinders until the filling tank is full. This type of filling is sometimes called Cascade Filling. 

What Do I Need to Fill?

Not much!  You’ll need the system itself (which runs between $2-$3,000, depending on what size system you decide), a paramagnetic oxygen analyzer, and a few filling supplies (like labels, valve seals and lot stickers.) Most gas to gas systems are wall mounted, so they have a small foot print. You’ll need to register with the FDA, and do some training, which most reputable manufacturers provide in their system packages. 

Is a Gas to Gas System Right for Me?