... G42,STPT42,STB42,STS42,STPT49,STS49Applicationpetroleum, construction ,shipbuilding, smelting, aviation, power, foodstuff, papermaking, chemical, medical equipment, boiler heat, exchanger, gas metallurgy ... thermodynamic fields, water supply engineering, steam heating, hydroelectric power station and long pipeline transportation projects.3.ends: 2" below plain ...