Description of S Pipe/S Valve/S Tube S valve is constructed of the plate. flanges, and splined shafts that have been joined together through welding. The splined shaft is made of 38CrMoAl, which has become a preferred choice tor manufacturers in making concrete pump S tube. Chrome-plated shatt sleeves are made ot #45 seamless carbon steel tube,witn the chrome plating thickness between O. 12mm and O. 16mm. The inner hole Of the s.shaped tube valve is welded up by wear-resistant welding electrode, Type: Sany/PutzmeisteflZoomlion/Kyokuto/Sermac/ClFA/HOLD/XCMG/SwcningConcrete Pump material : Welded pipe 16Mn: Shaft