... ASTM A234 WPB 4 Butt welded carbon steel pipe fittings Typecarbon steel pipe fittingsSize1/2" - 80"(DN15 - DN2000)Wall ... requirementApplications range petroleum, smelting, foodstuff, power, papermaking, chemical, medical equipment, aviation, boiler heat, exchanger, gas metallurgy, shipbuilding, construction, ... carbon steel elbow15. carbon steel seamless elbow high quality steel COUPLING fittings