John Lewis wrote:G'day papa,
Seem to recall meeting you on another forum. If I remember right you were using an ex medical oxygen generator. If I'm correct, would you mind giving a few details about it and how you find it. I have my sights on one but don't know much about their use.
John Lewis
Hi, John, My current setup consists of:
* Devilbiss 505DS Oxygen Concentrator (local second hand store purchase)
* Victor VTS710 fuel regulator (nearly any acetylene reg will suffice, but dual stage regs are noticeably better - also, if the reg has a CGA 580 fitting, as many do, it will directly attach to the BBQ bottle)
* 25ft.of 3/16", "T" rated alt fuel hose (acetylene hose is "R" rated)
* Victor model J-28 torch w/UN-J mixer and "TEN" series tips.
* 20 pound (5 gallon) standard barbeque bottle
This 505DS Concentrator produces about 97-98% pure oxygen at an adjustable 0-5 LPM, at about 8 PSI. I've since popped the cover on the unit and readjusted the output pressure to a more suitable 5 psi. The machine (like most others) has a tapered nipple for the output hose, so simply cut-off the brass fitting from oxygen (green) hose and just push it on the nipple - no need for even a clamp. I typically set the volume to 2-3 LPM.
You can use standard oxy-acetylene tips with propane, but lighting and adjusting the torch is a bit more difficult and breezy conditions aggravate the situation. The alt fuel tips differ from the O/A tips by having a slightly recessed orifice. O/P has a flame temperature of about 5000f, which is only about 300-400f lower than O/A - sufficiently high enough to easily braze most anything (as evident by the photos). However, because propane has a greater stoichiometric oxygen requirement than acetylene, (i.e. the ratio of the volume of oxygen to fuel gas are 1.2 to 1 for acetylene and 4.3 to 1 for propane), it's a bit easier to induce premature oxidation if the operator gets careless with mixture adjustments.
If you have any specific questions, please don't hesitate to ask.