The opening and closing part of stainless steel flanged gate valve Z41W is wedge disc, the movement direction of wedge disc is perpendicular to the fluid direction, the gate valve can only be fully open and fully closed, can ‘t be adjusted or throttled. Wedge disc has two sealing surfaces, the two sealing surfaces of most common mode of gate valve form wedge, the wedge angle vary with the valve parameters, Usually the angle is 50 , and it is 2 ° 52 when medium temperature is not high. The wedge disc of wedge gate valve can be made into one piece, which is called the rigid wedge disc; It can also be made into wedge disc which produces small quantities of deformation in order to improve its manufacturability, to make up the deviations of sealing surface angle arising during processing, this wedge is disc called the flexible wedge disc.