After looking at Sun N Fun and Oshkosh I did not find a cascading transfill setup that I thought made economic sense.  After searching the web I found Preece Precision on Ebay who sold a single tank setup with bleed valve and gauge for $59.95 shipped.  I blasted off a quick email to them and asked if they could make a two tank system.  A few emails later and for less than $110 they shipped a two tank cascading system to me (add $50 for each additional tank you want to add to the system). 

I did not want to need a wrench to take the portable tanks on/off of the system when filling them so I ordered a hand nut from Mountain High Oxygen to replace the hardware that Preece sent me.  Then I found a few 300cf oxygen tanks on Craig’s list and the system was complete.  The tanks came empty so I did have to take them and swap them at Airgas for $46 a piece but the tanks I got back had nice new paint, current hydro test date, and were full of oxygen!  Mountain High Oxygen does offer a nice inline bleed valve ($139 00HDW-0397-02) that you would mount on the end of the hose that goes to the portable tank that would allow the line set to stay filled with oxygen when you remove the portable tank but for the money I decided it was not worth the option.  The small amount of o2 you save did not pencil for me.

RE: Oxygen Welding Tanks

If the neck ring is stamped with a suppliers name on it that supplier is the only one who will exchange/fill it. It the neck does not have a supply house name on it then it is a “customer owned tank” and any gas supplier will fill or exchange it. Just make sure if they exchange it they give you a clean necked bottle again or now you are committed to them for the future as it will be branded with their name.  Additionally the gas suppliers seem to want to “rent” these larger bottles for $30 a month to you.  Most will not sell you a bottle this large but are happy to exchange your already owned bottle for a full one.

It is very important to clean your wrenches/tools with alcohol to remove any oil/grease from them before using them on the oxygen system parts.  The brass parts that are sold for oxygen have been cleaned to remove any cutting fluids from their manufacturing process.  You might find cheap brass fittings but making sure they are clean is another thing.  I found it better just to buy them from a reputable source.

Setup as it came from Preece Precision with the new hand nut and nipple waiting for assembly.

My (2) tanks from Craig’s List sitting on the right of the row after drop off, and the (2) fresh/filled tanks loaded in the car headed to the hangar.

Unloaded them by myself with a broken thumb so not all that hard to move the bigger tanks around.  They are not light though.

Finished setup.

Costs:

$300 – (2) 300cf tank from Craig’s list

$109.95 – (2) tank CGA540 cascade system – Preece Precision  (541) 706-9601 pcramer@preeceprecisionllc.com

$23.50 – CGA-540 Hand-Grip Nut (#00HDW-0362-00) – Mountain High

$22.00 – CGA-540 Nipple w/O-ring (#00HDW-0370-01) – Mountain High

$7.50 – PTFE Tape Oxygen Use Approved (#00VEN-0112-01) Mountain High

$92 – (2) 300cf tank swap – Airgas

$554.95 Total cost for two tank cascading system with full bottles