PLAN No. 1144. PIPE AND MAIN WORK
In the welding of pipes and mains, the process is finding increased application and this field presents good prospects of expansion in the future. Extensive work in this country as well as in Europe, where it is more largely used, has demonstrated that welding is not only the most economical method but as well the most efficient in that leaky joints are eliminated. Welding does away with threaded joints, and thus makes possible the use of much lighter pipe, since there is no need for making allowance in thickness for threading. Moreover, joint couplings are dispensed with. The expense saved in maintenance alone is tremendous, as the joint is water-tight and there is therefore little likelihood of trouble arising from leaks. In making connections, Y’s, T’s, crosses and drips are made on the spot, being cut out of odd lengths of pipe and fitted together. This effects an economy in that these odd pieces are saved.
The process has its greatest application in the welding of gas, steam, air, oil, water and ammonia pipes and mains, and the work is chiefly outside work, although it is used to some extent on interior pipe connections. Special fittings or connections may be welded in the shop. Outdoors welding is generally performed on sections of pipe while above the ground, the whole section being finally lowered into the ditch. The welding of these several sections to each other has to be done in the ditch or trench, a pit being generally dug in order to give the welder sufficient room for carrying on the work. Obviously this work requires suppleness in the worker.
Where there is a large amount of welding, the apparatus most commonly used is a portable generator, with which is mounted a set of oxygen tanks. In other cases a small two-wheeled truck carrying one oxygen and one dissolved acetylene cylinder may suffice.
In this kind of work, the welder is generally assisted by one or two helpers who do the heavy work, placing, holding, and turning the pipes while the welder keeps on welding. Some overhead welding is done which forces the welder to assume a strained position.