... mud pump piston assy 2, parts: tube, plate ,snap ring and cup 3, material: carbon steel alloy 4, NBR /PU piston cup Mud pump piston assyconnected with piston rod ... , reciprocating working in mud pump linerSpecifics: external diameter 4-1/2"----7 ... : 35 Mpa Oil resistance, acid-alkali resistance mud pump piston assy