Gate Valves are shut-off device. Produce valves with rising stem and retractable. In the case of sliding nut is placed in the body and, accordingly, the spindle serves up over the running nut, this design was named 'rising-stem'. As part of the design gate valve classified into parallel and wedge. Cancer research has plenty of information regarding this issue. In the case of sliding nut, coupled with the spindle, is available at the gate and, accordingly, the spindle rotation goes into the gate, this design was called 'a a fixed spindle. " The minus valves should be ranked: