Why is a propane cutting tip a two-piece tip?
(top) Propane only produces one half of the heat that acetylene does in its primary flame (inner cone). Propane also requires four times the volume of oxygen that acetylene does and is a much larger molecule than acetylene. In order for a propane tip to supply the same amount of heat from the inner cones of its pre-heat flames as an equivalent acetylene tip, it has to allow about five times more total volume of gas flow through it than the acetylene tip. This means youd have to drill many more holes in a single piece propane tip to achieve the required flow. It is not economical or mechanically feasible to drill so many holes in a solid copper tip so propane tips are made in two pieces that allow many slots to be milled into the centre core of the tip to provide the required flow and adequate heat. If acetylene is used in a two-piece propane tip it is much too hot and can cause overheating of the tip and possible backfiring into the tip.
