Torch tip design?

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All,Does anyone know a good source for information on burner/torch tip design?  I have all sorts of questions for someone who is knowledgeable.I have been comparing torches and tips from various manufacturers and have been trying to determine the unique advantages and disadvantages of each torch.  Specifically, I have been focusing on smaller aviation/sheetmetal torches since I am trying lto learn aircraft welding, and since this seems to be the last realm where oxy/fuel welding torches are still commonly used.  For example, I straightened a meco AV-2 tip which had been pinched almost flat and the resultant flame was what I would consider a long flame, while an unaltered AV-5 tip seems to produce a bulbous flame.It seems that the shape of the outer veil of a flame should be affected by two factors.  First, the velocity and direction of the flame leaving the tip orifice, and second, the velocity and direction of the surrounding air as it flows around the tip and is drawn into the flame.  I have used a W-45 torch with a #6 tip and found that the flame could be adjusted from a long flame to a bulbous flame by just using the valves to throttle the gas flow.  However, this is apparently not possible with many other torches, such a small airco that I have tried.  Also, both smith's and oxweld had both long flame tips and bulbous flame tips available for their torches during the 1940's.I am also interested in the characteristics of torch mixers.  Some torches, such as the smith AW1A, the victor J-40, and the oxweld W-29, use a different mixer for each tip.  However, the meco aviator, the meco aviator jet and the harris model 15 use only one mixer for all of their tips.  One small airco torch that I used used had two mixers, one for large tips and another for small tips.For safety's sake, it seems that a mixer would be limited on the low-flow end by flashback protection issues and on the high-flow end by overheating.  It also seems that a mixer should be designed to operate in conjunction with a tip shch that the tip never operates in the turbulent flow regieme for good flame quality.  Thus, the optimum mixer should have a design which thouroughly mixes the gases while having orifices which are large enough to prevent a large pressure loss, yet small enough to supress a flashback from the tip.  It should be designed to operate such that some tip or tips operate in the laminar flow regieme and thus provide a stable flame.Additionally, I have tried a W-17 injector torch and was suprised at its interesting characteristics when used with low aceteylene regulator pressure.  When setup like the manual directs, the acetylene valve independently adjusts the fuel/oxygen ratio, while the oxygen valve adjusts the flame size.  This seems like a very convienent feature for a sheetmetal torch and I have noticed that the oxweld w-29 is also an injector torch.I have also heard that a key advantage of the dillon/henrob torch is low gas pressure at the tip.  This supposedly prevents the the torch from blowing holes through thin sheetmetal when welding.  However, it seems to me that the tip pressure should be determined by the flame velocity and tip design, not by whether the torch is an injector torch or a balanced pressure torch.  Yet, It would also seem that an injector torch would have better pressure conservation, since one gas draws the other, rather than relying on a mixer to throttle or swirl the gasses together.  However, this would only present a major advantage in a situation where one gas is only available in low pressure, or where ease of operation is desired.Sorry about the length of this post.  I hope it answers some questions and inspires some useful discusson.                                                                                  Sincerely,                                                                                  Christopher J. Mikesell                                                                                  taylorcraft1947
Reply:taylorcraft1947   -   You have answered no questions.  All of your torch data means nothing unless you share the application.  What is the application?    Opus
Reply:Your best bet is to do the research yourself since you seem so inclined, and in aid of that I suggest making a standard "torch holder", perhaps like a simple test tube clamp, photographing a variety of flames, and noting the equipment and adjustment that produces them. Post the work and other can compare their equipment in the same manner.You could probably have great fun with a small, precision metal lathe.