So I have a Uniweld MC & R tank oxy/actylene set, and being a commercial tech, often find myself brazing 2" plus copper. I've had the Uniweld 17-15 rosebud for several years, but almost from the get-go and particularly the past two years, I've had issues with the rosebud tip in particular. Occasionally it would work great, but on jobs where several joints were made, it would start to sputter and act up, and the blue section (acetylene) of the flame would impinge and sputter, and the tip would get hot as hell, causing the O-rings to wear quick and the tip and handle to need a cleaning. During down time, I would disassemble, clean, and replace the o-rings, it would somewhat work for a while, and then the cycle would repeat. A couple days ago, I was on a job where I had to work quickly on 3" copper, and of course, the tip started acting up and actually got plugged. I said "F this" and immediately ordered a new tip and handle, this time going to the 17-30 rosebud -- same price, but can braze bigger pipe. I just got the tip, and I noticed that it says on the packaging "for use with B acetylene tank or larger," and I wonder if this has been my problem all along. I would keep my MC & R pressure regulators set to 10 and 20, respectively, and use the handle to tweak. I did notice issues when the tanks got low that the regulators would have trouble keeping up, but have any of you guys experienced the tip burning issue? Do any of you use rosebuds with the MC acetylene tanks and have trouble?