Nov.07.2024
Gate valve has the characteristics of small fluid resistance and wide applicable pressure and temperature range. It is the most commonly used cut-off valve and is used to cut off or connect the medium in the pipeline.
2. Concealed stem gate valve:
Concealed stem gate valve is also called rotating stem gate valve (also called concealed stem wedge gate valve). The valve stem nut is in the valve body and in direct contact with the medium. When opening and closing the gate, the valve stem is rotated.
The opening and closing part of the hidden stem gate valve is the gate plate. The movement direction of the gate plate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, but cannot be adjusted or throttled.
The valve stem nut is set on the gate plate. The rotation of the handwheel drives the valve stem to rotate, which lifts the gate plate. There is usually a trapezoidal thread at the bottom of the valve stem. The rotating movement is carried out through the thread at the bottom of the valve and the guide groove on the valve disc. It changes into linear motion, that is, the operating torque is changed into operating thrust.
1. The lifting screw of the concealed stem gate valve only rotates without moving up and down. Only a rod is exposed, and its nut is fixed on the gate plate. The gate plate is lifted by the rotation of the screw. There is no visible door frame; The lifting screw of the rod gate valve is exposed, and the nut is close to the handwheel and is fixed (does not rotate or move axially). The gate is lifted by rotating the screw. The screw and the gate only have relative rotational motion and no relative axis. It moves in the direction and looks like a door-shaped bracket.
2. The lead screw cannot be seen in the concealed stem gate valve, but the lead screw can be seen in the open stem gate valve.
3. When the concealed stem gate valve is opened and closed, the steering wheel and the valve stem are connected together and are relatively immobile. It opens and closes by rotating the valve stem at a fixed point to drive the valve disc upward and lower the gate. The rising stem gate valve raises or lowers the valve disc through the threaded transmission of the valve stem and the steering wheel. To put it simply, the rising stem gate valve moves the valve disc up and down together with the valve stem, and the steering wheel is always at a fixed point.
