From four valve types, which is most effective for controlling pressure in a refrigeration system?

• A. Globe valve
• B. Plug valve
• C. Gate valve
• D. Ball valve

Answer: (B)

Controlling pressure in a refrigeration system hinges on precise throttling of the refrigerant flow. A globe valve is designed for fine control: its disk moves against a globe-shaped seat, producing a nearly linear change in flow as the valve is opened or closed. This gives predictable, adjustable resistance and smooth regulation of pressure. Gate and ball valves are excellent for turning flow fully on or off, but their flow characteristics aren’t ideal for throttling—openings can cause abrupt changes or high velocity that make pressure control less stable. Plug valves can provide throttling in some designs, but they generally don’t offer the same smooth, proportional flow control as a globe valve and are more common for on/off or mid-range service. So, for reliable and precise pressure control in a refrigeration system, the globe valve is the best choice.