The use of pintsch gas and oxygen for hot-flame welding is the latest addition to the list of possible systems for general use, and was developed by the Safety Car Heating and Lighting Company, New York, primarily for use by steam railroads. It is as general in its applications, however, as any of the other systems and the fact that every railroad has pintsch gas on its cars and supply stations at frequent intervals should result in a wide application in shops which have no electric-arc welding apparatus. The principal feature of this process seems to be in the use of a special torch, as with the other gas systems, and the apparatus is similar.
The apparatus consists of the two steel cylinders for the gases, valves for regulating the pressure, tubes for the gas, and the special torch. The pintsch gas is furnished at a pressure of 100 atmospheres (about 1500 pounds) and the oxygen at 150 pounds. The gas can also be obtained at 180 pounds pressure. The high pressure gas is reduced in two steps when used, the first being from 100 atmospheres to 14 atmospheres and then down to the 25 pounds required at the torch. The torches for this process are made to take the two tubes feeding the two gases and mixing them in a chamber at the back end, and a valve is provided in each inlet. The tip of the torch contains a preheater which operates by internal combustion and produces a high temperature, non-oxidizing flame. This feature of the torch is valuable and adds to the temperature of the flame.
The process of welding with the oxy-pintsch flame is the same as with the oxy-acetylene flame, but the manufacturers claim considerable saving in cost of operation. They give 3.4 cents as the cost of cutting one foot of an 18-inch channel 15/32 inch thick, and the total cost of the work done on the channel was 86.2 cents against the old cost of $4.66 by drilling and chipping. No figures are available at this time for welding operations, but all sorts of articles can be successfully welded and cut by this process. The preparation of the joints should be the same as for other gases and the metal should be handled in the same way.