Which valve type uses linear motion to regulate flow?

• A. Butterfly valve.
• B. Globe valve.
• C. Swing check valve.
• D. Ball valve.

Answer: (B)

Movement in a straight line to adjust flow is how throttling is achieved, and the globe valve is designed around that principle. In a globe valve, the stem moves a disk (or plug) straight toward or away from the seat as the valve is turned, creating a variable opening that precisely regulates flow. This linear travel provides fine control, which is ideal for throttling applications.

Butterfly valves rotate a disk around a central axis to modulate flow, not by sliding a part linearly. Ball valves also rely on rotating a spherical ball to open or close, offering on/off control rather than fine throttling. Swing check valves use a disc that swings open or closed with flow direction and are primarily for preventing backflow, not regulating flow.