1. This valve is mainly composed of the valve body, valve cover, gate, valve stem, sealing ring, double-acting cylinder and its piston, piston rod, spacer along with the buffer mechanism, manual mechanism, pneumatic-manual conversion device, and valve cover packing device, etc.
2. When the upper piston moves to the top end of its travel and touches the upper limit switch, it sends an "open" position signal; when the lower piston moves to the bottom end of its travel and touches the lower limit switch, it sends a "closed" position signal. These signals are displayed on the analog instrument panel in the central control room as information about the opening and closing of the gate valve.
3. The rise and fall of the extension indicator rod at the top of the handwheel indicate whether the gate of the valve is in the lifting position or the lowering position. When the gate valve is closed, the extension indicator rod is at its lowest position; conversely, when the gate valve is fully open, the extension indicator rod is at its highest position. This serves as a local indication of the valve's open/closed status.
4. The upper part of the cylinder head is equipped with a pneumatic-manual conversion device. To put the valve in pneumatic operation mode, turn the conversion handle clockwise to position it in the pneumatic positioning hole; on the contrary, turning the conversion handle counterclockwise to position it in the manual positioning hole allows for manual operation of the valve. For handles with bevel gears, the direction of rotation is reversed. When operating the valve manually, the rotation direction of the handwheel is the same as that of a regular manual valve, i.e., clockwise to close and counterclockwise to open. For those with bevel gear rotation, it is opposite.
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