I need some torch advice.

[Northweldor]

Can someone please explain what the NUMBERS and the words SIZE means in the 4th column in this chart!........To me its pretty self explanatory, and not based on inventory/shelf/part number or theoretical fuel flows....



Dale

The numbers in the SIZE column indicate the smallest to the largest in rosebud tips in terms gas consumption / BTUh output. There is nothing "theoretical" about the fuel flows.

[oldguyfrom56]

4-6-8 who do we appreciate...


9 -15psi...hmm? That's a bit of a point spread that must account for something?

I've never in my life run a rose bud for longer then minutes at a time. That said, If I had a "B" tank, hooked to a rose bud, kept it lit and burning, what's going to happen as a result of doing so?

Held back it won't over heat. As long as the cylinder pressure holds the flame will stay adjusted. And the acetylene gas will continue to leave solution at the same rate regardless of cylinder size so what's really the worry? The worry is it seems over heating the tip, unbalanced gas pressures, hose to small to supply the volume being drawn from the cylinder.



Most heating I do is with a 6 hole cutting torch tip. That said, I also have never drawn a continuous gas flow to empty a cylinder?
Have I seen signs of drawing acetone, yes. Sparkles, change in flame color...

I've read the amount of acetone is generous enough in the cylinders to prevent the cylinder reaching an explosive condition if rates of drawn gas are exceeded and acetone is drawn from the cylinder? I'm sure there is a good reason you don't hear more stories of exploding gas cylinders, because they don't unless other conditions or causes are present beside consumption.

Bumped by a errant fork lift operator maybe?

[Northweldor]

For the OP and any others who are still interested in acetylene rosebud heating, the tables below, for Miller-Smith rosebuds and Air Liquide rosebuds show a little different approach. Rather than simply showing the acetylene draw rate according to tip size, they also recommend cylinder size requirements for each size.

This approach is even more discouraging for acetylene rosebud heating than the Harris article I quoted in a previous post, since it totally rules out the idea of using their equipment according to instructions and still having it portable, as the OP requested.




Note that Miller-Smith, for example. is recommending for its 124,670 BTU tip, (ST605) TWO 350 CF cylinders @ 70 degrees F, while the 71,750 BTU (ST603) still requires one of these 200 lb. monsters. For comparison, a size # 8 Victor rosebud is 117,600 BTU.

Aire Liquide 735, tip Size # 10 also covers about the same range of BTU (109,000 to 125,000) as the Victor Size # 8
( 117,600), but they recommend two cylinders manifolded for this rosebud.

For the hobby-welder these two companies rule out easy portability for almost any but the smallest size rosebuds.


Finally, these tables bring up another factor which has been ignored so far in this thread. The possible draw-rate from acetylene cylinders decreases significantly with a drop in temperature, and with a decrease in cylinder pressure. I always return acetylene as soon as the pressure drops below 40-50 psi., so that I will not draw acetone in cold weather, or, when the cylinder is nearly exhausted.

I would guess that these companies, like Harris, are also not encouraging small acetylene cylinder use with rosebuds.

[Sberry]

MAPP gas is useless for your purposes if you tried it without oxygen. Also, any oxy-propane outfit with disposable cylinders would likely be useless.

However, if your needs are only heating, cutting, and brazing, as stated in your original post, you should not be listening to "everyone" mythology. An oxy-propane torch would do just as well, at far lower expense. In fact, the great majority of manual preheating in the welding industry is done with propane for exactly this and other reasons.

The reasons are:
the max.temperature of a neutral OA flame is 5720 F. while the max temp of a neutral OP flame is 5112 F, However, the amount of heat per cubic foot of gas is 1470 BTU's for acetylene, and 2498 BTU's for propane, so even though the flame is slightly cooler in max. temperature, the amount of heat produced by propane is actually much larger per cubic foot, making it MORE efficient for heating purposes. OP will also easily reach the 1100 - 1500 Fyou need for heating, will cut and braze almost as well, and you only need to buy one cylinder. (Use the propane from your barbecue).

Also, you can buy torch sets that will work for both OA and OP with only a change of tips and hoses, if you later decide you need welding ability or the greater precision of the OA torch.

Yes, no cheaper way to do this and a 20# bottle of LP really lasts a long time and is cheap if a guy looks around for a fill. I used it at one point before plasma, had a Bud in auto repair use it for a career.
It looks like someone burned that tank open either to demo it or as a demo piece.

[losduarte]

National Fire Protection Association (NFPA) Codes prohibit storage of propane tanks in a residence (key word here is "in" and includes garage).... It allows that 2 16 oz canister may be stored in a residence.....
https://www.nfpa.org/codes-and-stand.../detail?code=1

The NFPA since 1995 has permitted the storage of LP tanks in residences:

8.3.5 Storage Within Residential Buildings. Storage of cylinders within a residential building, including the basement or any storage area in a common basement of a multiple-family building and attached or detached garages, shall be limited to cylinders each with a maximum water capacity of 2.7 lb (1.2 kg) and shall not exceed 5.4 lb (2.4 kg) aggregate water capacity per each living space unit.

NFPA 58, § 8.3.5

https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=58

Many states have not adopted all of the NPFA in their residential building codes.