The bonnet type DVD Gate Valves have a revolving non-rising stem, provided with a functional thread which is inside the valve chamber.
During the operation, stem revolves in the stem nut which carries along a flexible wedge. Due to its design, low torque values are achieved which eases the revolving of the stem.
The stem is locked against axial movement by a bonnet nut threaded to the bonnet, and no axial movement occurs in the specified conditions.
The wedge is guided in the body in a precast groove and provides an undisturbed water flow when the valve is open.
The body and the wedge have pressed-in/ threaded sealing seat to have drip tight sealing when the valve is closed.