PURPOSE: To prevent damage to a gate by forming sleeves and inset rings from a hard wear resistant material, and mounting and keeping the sleeves and the insert rings in respective positions under compressive preloads such that they resist damage during the operations of closing, sealing, and shearing a valve.

CONSTITUTION: Seat rings 34, 36 made of tungsten carbide or the like which has little tensile strength are fitted into dents 38, 40 in a main body 12, and prior to assembly the inner dent is given a smaller bore than that of insert rings 46, 48 and heated in order to permit the insertion of the insert rings 46, 48 without application of undue load. A gate 32 is connected to a connecting rod 30 and is heated and shrink fitted to allow a sleeve 44 of hard material to be easily inserted into an opening 42. Therefore a wire or the like which passes through a gate valve 10 can be sheared without causing damage to the hard inserts 46, 48 and the hard sleeve 44, and the valve 10 is used without repair through a number of cycles of closing and shearing.