A globe valve is a linear motion valve used to stop, start, and regulate the fluid flow. The globe valve disk can be removed entirely from the flow path, or it can completely close the flow path. During the opening and closing of the valve, the disc moves perpendicularly to the seat.
This movement creates the annular space between the disk and seat ring that gradually closes as the valve closed. This characteristic provides the globe valve good throttling ability required for regulating the flow.
Leakage from the globe valve seat is less as compared to the gate valve, mainly due to right angle contact between the disc and seat ring, which allows tighter seal between seat the disk.
Globe Valve Disk Types:-
- The ball disk: design is used in low-pressure and low-temperature systems. It is capable of throttling flow, but in principle, it is used to stop and start the flow.
- Needle disk: design provides better throttling as compared to ball or composition disk design. A wide verity of long and tapered plug disks are available to suit different flow conditions.
- Composition disk : is used to achieve better shutoff. A hard, non-metallic insert ring is used in composition disk design.