Update on my torch

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i called another welding shop in my town they are cheaper than airgas i can get a 80 cubic foot oxygen bottle and a 135 cubic foot bottle with a 1 year lease on both bottles i was gonna get a 5 year lease but they don't have that anyway i can get a 1 year lease on both tanks and have both bottles filled the leases and the gas for 200 bucks i forgot to say the 135 cubic feet bottle is acetylene
Reply:135cf acetylene is a larger than average "hobbyist" size. Note that for welding you usually go thru roughly 1 to 1 acet and O2. With cutting you got thru O2 much faster, almost 3 to 4 times as much O2 as acet. My 75 cf acetylene cylinder runs out roughly about the same time my 282 cf O2 does when cutting.You might want to look at your intended use and see if the cylinder size fits your intended purpose. One reason for getting a larger acetylene would be if you intend to run big tips or do a lot of heavy cutting or heating. Then the extra volume will allow you to stay within the 1/7th rule for withdrawl. My 75 cf is borderline with anything but the smaller tips for cutting and really too small to use even my small rosebud except for very short periods of time..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:What's the 1/7 rule? How do you go about sizing your bottles?
Reply:The 1/7th rule is the amount of acetylene that you can withdraw from a cylinder in an hour and not cause issues. Acetylene is stored in solution and needs to "boil" out to be used as a gas. If you exceed the withdrawal rate you will pull the acetone out of the cylinder that is used to dissolve the acetylene and keep it stable. Acetone is also very hard on the regs and hoses.As far as sizing, take a look at this chart. It shows the tip size and on the right the suggested flow settings in SCFH, or cubic feet per hour. So if you have a 75 cf acetylene cylinder, you should avoid using a tip that requires you use a flow rate higher than roughly 10 1/2 CFH. Note that a Victor cutting tip larger than a 0 will require more gas than a 75 cf cylinder can provide under the 1/7th rule. A 40 cf  would be limited to a tip that uses 5.5 cf per hour which would limit you to the smallest Victor cutting tip, 000.http://www.hoopersupply.com/tipchart.htmlNewer manuals restrict you even farther since now they recommend a withdrawal rate of 1/10th rather than the "traditional" 1/7th. All of this is basic OA 101. If you aren't familiar with this, you should probably dig up a basic manual on OA welding and cutting and read some. Victor, Harris and Smith all have basic info available on line I believe..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:It seems like the rules of withdrawal are not safety issues per se but rather recommendations to avoid getting acetone vapor carry-over.From the CGA G1:Acetylene (US law):* Experience has shown that for welding, cutting, and allied processes, a withdrawal rate of 1/7 of the cylinder capacity per hour is generally acceptable;* To minimize the withdrawal of liquid solvent in applications that are more sensitive to solvent carry-over, acetylene should be withdrawn from the cylinder at a rate not to exceed 1/10 of the capacity of the cylinder per hour during intermittent use, and for withdrawal of the contents of the cylinder on a continuous basis, the flow rate should be no more than 1/15 of the capacity of the cylinder per hour;
Reply:Thanks DSW!