Preheating gas pressures for Amoterm welding (TM-FM-61)

At present, the rail end preheat for Amoterm welding is obtained by heating for a fixed length of time (5 mins for B.H. and 6 mins for new F.B. rails). Until recently, the gas pressures used had been 70 p.s.i. for oxygen and 24 p.s.i. for propane, which have, however,...