09.14.07

World Pro Instant Air System - Filling tanks

Posted in Tool Bits at 11:08 am by shane

I have been spending a lot of time playing with the new World Pro Instant Air System, for those of you that aren’t familiar, its a system that used liquid co2 tanks for anything air powered. Use it to to power your pneumatic stapler, fill tires, clean out computers, pretty much on anything that is air powered or as a general replacement for your air compressor.

I have found that filling the tanks is a bit tricky, so I hope my experience will be helpful to you and save you the time.

I bought my own 15 pound aluminum cylinder for CO2. You should make sure you get a tank rated for storing CO2, and it must be aluminum. CO2 stored at high pressures can cause corrosion in a steel cylinder – as much as 22mm of corrosion over a period of a year (This is what I was told. It may not be precise, but from the sounds of it, stick with aluminum).

I bought the CO2 tank from a Fire & Safety Company (this seemed like a good idea at the time). They filled it for me the first time. I took it back to my shop, got out my two 20 oz. CO2 Tanks and my scale. It has been recommended that the tank be chilled before filling. I can tell you very simply, you cannot fill a warm tank. Your cylinder MUST be cold - frosting on the outside.

My first few attempts to fill my tanks yielded very poor fills because I did not properly chill the tanks. Also, my 15 pound cylinder did not have a siphon tube. This means that unless I tipped the tank over, I was getting CO2 gas into my small cylinders, not liquid CO2. There was no way with that bulk cylinder I was going to safely fill my tanks to the maximum capacity.

At that point I took my bulk tank and small cylinders to a local Industrial gas supplier. They wouldn’t fill my tanks. It wasn’t their bulk tank, so they wouldn’t help, support or fill it ( apparently this is quite common, so check around with your local suppliers if you plan to get a bulk tank to see who will and who won’t fill the tank for you).

I then found a great local company called Camcarb. They have an amazing support team and a knowledgeable technical team. I proceeded to ask them question after question until I fully understood the process for filling a CO2 tank. Eventually I followed their technician into the back and watched him fill my small tanks.

Here is a picture of a CO2 Refill station (sometimes called a pigtail). The one they used was actually made of pipe, not hose (the concept is the same). It has an adapter to fit the bulk tank and 2 valves: one valve to shut off the bulk tank feed (valve 1), one valve to bleed the line (valve 2) and an adapter for the small tank (fits needle valves). The small tank adapter is strange in that it has a valve actuator to open the needle valve on the small tanks.

Here are some quick and dirty instructions for filling tanks with a pigtail:

• Ensure the bulk tank is not on.
• Back off the valve actuator so that it doesn’t engage the needle valve.
• Put the pigtail on the bulk tank.
• Close both valves on the pigtail.
• Screw on your small tank.
• Turn the valve actuator until its engaged into the needle valve opening the small tank.
• Open the bulk tank.
• Open valve 2.
• Drain your small tank .
• (Once the small tank is empty)
• Close valve 2.
• (If your tank has been refrigerated and has frosted from draining it, then you can skip the next part)
• Open valve 1, fill the small tank.
• (once the hissing has stopped)
• close valve 1.
• (Wait a few seconds for the gas to settle in the tank and chill a bit)
• Open valve 2.
• (Once the small tank is empty)
• Close valve 2.
• (your tank should now be visibly chilled)
• Open valve 1 and fill the small tank.
• close valve 1.
• Unscrew the valve actuator.
• Open valve 2 (to relieve the pressure in the line)
• Unscrew your small tank.
• WEIGH YOUR TANK, to make sure you have added 20 ounces or 567 grams of liquid CO2.

I showed him my bulk tank adapter (a small aluminum coupler that comes with the World Pro Instant Air System) and asked him how he felt about it. He said it should work, but would take a little more work than using a pigtail with valves on it. Confirming my thoughts, my trouble had been caused by operator error.

Once I got back to my shop with my 15 pound cylinder filled, I got 2 more empty (room temperature) 20 oz tanks, and put one into the freezer for 10 minutes.

Here are the instructions I have come up with to fill the small tanks with the aluminum coupler (bulk tank adapter):

• Ensure your bulk tank is off.
• Attach the bulk tank adapter (the adapter should be cold also).
• Screw your small tank into the bulk tank adapter.
• Turn on the bulk tank.
• (a warm tank won’t get more than about 100 grams or 3 1/2 ounces of CO2)
• Turn off your bulk tank ( once the hissing slows or stops)
• Remove the small tank.
• Drain your small tank (You’ll want to drain it fast so the tank gets cold to the touch. If you drain it too fast, the liquid will
• Turn into Dry Ice. This probably won’t help you fill your tank to capacity, so wait until the dry ice turns back into gas / liquid)
• re-attach your 20 oz tank to the bulk tank.
• Turn on the bulk tank.
• Turn off your bulk tank (once the hissing slows or stops).
• Remove the small tank.
• WEIGH YOUR TANK, to make sure you have added 20 ounces or 567 grams of liquid CO2.

Now, I still had to fill and drain the tank I put in the freezer (maybe I didn’t leave it long enough). I strongly suggest you get a 50 pound tank, because a refill will last a long time. Do not get a 15 pound tank, because it give only 8 - 11 fills.

An empty tank weights around 800 Grams (1.7 pounds).
A full tank should weight around 1370 grams (3 pounds), and contains 567 grams or 20 ounces (1.25 pounds) of liquid CO2.

Here’s a funny story that illustrates why you should weigh your tank when it’s filled:

I filled a tank but didn’t weigh it. Then I put it in the trunk, figuring it would be good to have it available. The next day it was very hot, and I heard a hissing noise coming from the trunk. When I opened the case, I got a lot of snow! Apparently an overfilled tank in the trunk of a car doesn’t do well. The good news is the safety valve blew, which is proof that the system is designed to prevent serious problems. I had to replace the ASTM safety valve (burst valve) on the tank and shake the snow out of my case. It was no big deal, since I got an extra valve in the case.

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