Which two types of globe valves are mentioned in association with gate valves?

The correct answer identifies needle valves and plug discs as the two types of globe valves mentioned alongside gate valves.

Globe valves are designed to control flow in a piping system, and they operate by moving a disk (or plug) into the flow path to vary the flow rate, which makes them distinct from gate valves that are either fully open or fully closed. The needle valve is characterized by its ability to provide precise flow control, which is crucial in systems requiring fine adjustments. The design allows for a small flow area, effectively controlling the fluid flow. Similarly, a plug disc is designed to provide a sealing mechanism that can also regulate flow, functioning in a manner that parallels globe valves.

Understanding the relationship between these components is essential for recognizing their functions in fluid control systems, especially in contexts where precise regulation is necessary.