Rosebud torch selection for proper SCFH

I would like to find myself a rosebud torch for my Victor 315FC handle. The warnings on rosebuds say that I may not exceed the use rate of 1/7 of my cylinder capacity in SCFH (cubic feet per hour).

I have a 350 cubes cylinder and I want to know up to what MFA number I can go safely.

i
Reply to
Ignoramus4389
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The one seventh rule which may well have been bumped to one tenth by now the way I understand it it for half full tanks at room temperature and a continuous draw. If the tank is full it is 90 degrees F and you don't use it very long perhaps you could use a 70 cubic foot per hour rosebud or single flame welding/heating head and be ok by the rules. Actually I have never seen how to adjust the rule for say 45 degrees and only a quarter of the tank left. Propane is rather easy to manifold guys doing hot tar roofing or temporary heat during the winter for constriction come to mind. I don't know how to wander around victor/thermadyne website but you can pull up oxweld manuals pretty easy at

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short answer is the smallest rosebud perhaps they have one that fits in the cutting attachment that size as well. Apparently (read somewhere) brass isn't good for manifolding acetylene tanks copper or iron or steel. I have only seen one acetylene manifold at a factory and each tank had a device in it's attachment tube and then there was a larger device perhaps the size of two volley balls one on top of the other nearby.

Fran

Reply to
fran...123

Thanks a lot.

So, Fran, if I have a 350 CF tank, and a Victor 300 type torch, how big of a MFA number torch can I have? Would 8-MFA work?

i
Reply to
Ignoramus22979

I didn't see the original post. But, if you want to do heating with a rosebud, you might consider adding a propane tank and regulator to your outfit. Get a propane rosebud instead. No such restrictions there that I know of. I also have both acetylene and propane cutting tips. I almost always use propane for cutting, too.

I save my acetylene for welding and brazing.

Pete Stanaitis

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fran...123 wrote:

Reply to
spaco

Pete, do those propane outfits use regular tanks that are used for grills? Or something else?

Are you using propane because you cannot get enough acetylene flow, or to save money you spend on gas?

i
Reply to
Ignoramus22979

I would think that your local welding supply would have tip charts for Victor, I got a bunch for free a number of years back, or maybe they've got the info as a PDF on their website now. They've got the flow-rates on the charts.

What are you heating that you need that much heat? I've seen guys welding railroad tracks via thermite preheating using a special head, but the fuel gas was propane. Seemed to heat the tracks up to red pronto, would be a lot less expensive than using acetylene. 50 cu-ft/ hr is a LOT of acetylene.

For bending bar for stakes and stuff, I've used the tip that came with the kit, heated 3/4" stock to red in just several seconds. Good enough for my purposes.

Stan

Reply to
stans4

Stan, I basically have no idea what size tip is really appropriate, I am just asking. I was melting some lava rocks for kids entertainment, (to make "lava"), with the cutting attachment, and wanted more heat.

i
Reply to
Ignoramus22979

in the first post I made I don't know how to edit and now think copper is not good for the acetylene piping the brass is supposed to not contain too much copper.

One seventh of 350 is 50 so that would be a consumption of 50 standard cubic feet per hour. I don't have any victor manuals and don't know what MFA means. Their equipment must come with manuals I can't figure out their website. Does a 8-MFA have a cfh number which corresponds? Esab lists a wk

300 cubic foot tank and a wlt 390 cubic foot size tank the bigger one is rated for a 55 cubic foot per hour rosebud without manifolding and the smaller calls for two. They also call for manifolding 100 pound propane tanks of varying number depending on the rosebud size as well so don't think a 20 pound barbecue tank is any answer if you want to follow the manual. I find the acetylene tank business frustrating as you not only have the size of the tank but they tag it as to how much they actually put in. You probably would want something around eight holes in the #55 drill size of course how far you turn it up matters as well. You asked about following the rules not has worked for a minute or so with no ill effect.

I don't know what you are doing, I have found that burying in charcoal which is burning works best for bending pipe (conduit) filled with sand using a torch it would tear.

Fran

Reply to
fran...123
[snip]

No. Pure copper and acetylene are explosive together. One must use brass. I forget the required composition. Some serious research is required before cobbing up one's own manifolds for acetylene.

Joe Gwinn

Reply to
Joseph Gwinn

Or buy the proper fittings from Western.

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Two tanks can be tee'd together with a Female-Male-Female tee and a Male-Male pigtail, and perhaps an extension if your tanks are the type with POL fittings and a ring around the top. This isn't a true manifold, since you can't leave both tanks open at the same time, but it does allow you to keep two tanks connected and choose the fuller tank when drawing a lot of gas and quickly switch to the other when you don't need high flow.

Besides the flow vs. tank size issue, even a large tank won't deliver enough gas for a rosebud when the tank pressure is low. The above setup allows you to conveniently use the remainder in a bottle for cutting and small tips.

Reply to
Ned Simmons

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