Lampwork boro beads are being made with a GTT Cricket torch and one Invacare Mobilaire V oxygen concentrator in place of bottled oxygen. Cost for bottled, in Anchorage, for 125 cu foot is $40 ($36.73 plus $2.50 hazardous materials fee) at Airgas. And just about $60 for the larger bottle.
Bead making is slow when sizes approach 22 to 24 mm in diameter using boro glass for the final melt down. In planning for a larger GTT torch, a pair of DeVilbiss oxygen concentrators were obtained. These units produce 9 PSI in comparison to the Invacare at 5.5 PSI.
A test was done with the DeVilbiss and the Cricket. The flame looks about the same, but not the heat. Now the boro glass melts faster and it is necessary to work farther out in the flame. This indicates a much hotter flame. Even though the Cricket is designed for low LPM oxygen it would appear that 9 PSI produces a noticeable increase in torch power.
The next test will be to combine both DeVilbiss machines by using two check valves and a Y connector. The new torch will have a Cricket inner flame with an outer ring for additional heating. Thus the need for 10 plus LPMs. The Invacare may be sufficient for just the outer ring, but at this point it does look marginal.
It would be nice to test the three units for actual LPM, pressure and oxygen purity. These devices run from $250 upwards. Thus making limited use too cost prohibited.