‎Parts of a typical globe valve

A globe valve is a type of linear motion valve primarily designed to regulate flow in a pipeline. It comprises several key components:

1. Body: The main outer casing that houses the internal components. It's usually globular or spherical in shape, giving the valve its name.

2. Bonnet: This is the cover or top portion of the valve body. It holds the stem assembly and is designed to provide leak-proof sealing.

3. Valve Seat: The valve seat is a crucial part that creates a seal against the valve disc or plug, preventing leakage when the valve is closed.

4. Valve Disc or Plug: This component controls the flow of the fluid by moving up or down, guided by the valve stem. When the disc is lifted or lowered, it changes the flow area through the valve, regulating the flow rate.

5. Stem: The stem is a rod-like structure that connects the handwheel or actuator at the top of the valve to the valve disc or plug. It transmits the force from the operator to the valve for opening or closing.

6. Handwheel or Actuator: The handwheel is typically seen in manual globe valves. It's used to turn the stem, raising or lowering the disc to control the flow. In some cases, globe valves are equipped with actuators (such as electric, pneumatic, or hydraulic actuators) for automated control.

7. Stem Nut: The threaded portion of the stem that engages with the valve disc or plug. When the stem is rotated, the nut moves along the threads, causing the disc to rise or fall.

8. Packing Gland: Located between the bonnet and the stem, this component houses the packing material, which prevents leakage along the stem.

9. Packing Material: Typically made of materials like graphite, PTFE (Teflon), or other resilient materials, the packing creates a seal around the stem, preventing fluid from leaking out of the valve.

10. Backseat: This is a feature present in some globe valves that allows the stem to be fully extended when the valve is fully open, providing a seal at the back of the valve to prevent leakage from the gland packing area.

These components work together to control the flow of fluids through the valve. When the handwheel or actuator is turned, the stem moves, raising or lowering the disc to either allow or restrict the flow of the fluid through the valve. Proper maintenance and care of these components are essential to ensure the efficient operation of the globe valve.