VALVE STEM PROTECTING DEVICE FOR INSIDE SCREW TYPE GATE VALVE

摘要

PURPOSE: To suppress the wear of the male screw of a valve stem and the female screw of a female screw piece, specially the wear of the female screw of the female screw piece formed of metal with low hardness so as to prolong a service life. ;CONSTITUTION: The protruding part of a valve stem 4 protruding downward from a female screw piece 3 at the ascending time of a valve body 1, and the lower end of a female screw 3a in the female screw piece 3 are covered in the water tight state with a first protecting cylinder 9. The valve stem 4 positioned on the upper side from the female screw piece 3, and the upper end of the female screw 3a are covered in the watertight state with a second protecting cylinder 12. The upper end part of the second protecting cylinder 12 is inserted elevatingly and in the watertight state into the lower end part opening 15A of a third protecting cylinder 15 fixed to the lower face of a stand 6.;COPYRIGHT: (C)1995,JPO