Gate valves are commonly used in industrial applications to control the flow of fluids within pipelines. They consist of several key parts that work together to open, close, and regulate the flow. Here are the main parts of a gate valve:

1. Body: The body of the gate valve forms the main structure of the valve and contains the internal components. It typically has flanged, threaded, or welded connections for installation into the pipeline.

2. Bonnet: The bonnet is the cover or top portion of the valve body. It provides access to the internal components of the valve, such as the stem, gate, and seat, for maintenance and repair.

3. Gate: The gate is the movable component that controls the flow of fluid through the valve. It is usually a flat or wedge-shaped disc that moves perpendicular to the direction of flow to open or close the valve.

4. Stem: The stem is a shaft connected to the gate that extends outside the valve body. It is used to raise and lower the gate to open or close the valve. The stem may have a handwheel, gearbox, or actuator attached for manual or automated operation.

5. Seat: The seat is the sealing surface against which the gate makes contact when the valve is closed. It ensures a tight shut-off and prevents leakage of fluid when the valve is in the closed position.

6. Wedge: In wedge gate valves, the gate is wedge-shaped, allowing for a tighter seal against the seat when the valve is closed. This design is commonly used in high-pressure applications.

7. Body/Bonnet Joint: The body and bonnet are joined together by bolts or studs and nuts, forming a pressure-tight seal to contain the fluid within the valve.

8. Packing Gland: The packing gland is a component of the bonnet that houses the stem and provides a seal to prevent leakage of fluid along the stem. It contains packing material, such as graphite or PTFE (polytetrafluoroethylene), that forms a tight seal around the stem.

9. Handwheel or Actuator: For manual operation, gate valves may have a handwheel attached to the stem, allowing operators to open or close the valve by rotating the handwheel. In automated systems, an actuator, such as a pneumatic, electric, or hydraulic actuator, may be used to control the valve remotely.

These are the basic components of a gate valve. Depending on the design and application, gate valves may have additional features or variations in their construction. Proper selection, installation, and maintenance of gate valves are essential to ensure reliable and efficient operation in industrial processes.