Preheating gas pressures for amoterm welding (TM-FM-061)

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,...