What is the operational difference between a globe valve and a ball valve, and how are they typically used in a cold water system?

• A. Globe valve provides throttling control with more pressure drop; Ball valve offers quick shut-off with minimal pressure drop.
• B. Globe valve provides rapid isolation; Ball valve throttles flow gradually.
• C. Globe valve is only for gas lines; Ball valve is for water lines.
• D. Globe valve is corrosion resistant; Ball valve is cheaper but non-repairable.

Answer: (B)

The main distinction is how they handle flow control versus isolation. A globe valve moves a disk toward or away from a seat to create a variable opening, which allows you to adjust flow gradually and precisely. That throttling capability comes with more resistance and a higher pressure drop as you restrict the passage. A ball valve uses a spherical ball with a bore inside; when the bore is aligned with the pipe, flow is allowed with very little restriction, and a quick 90-degree turn shuts it off tightly. This makes ball valves excellent for fast, positive shut-off and low pressure drop when open, but not ideal for fine flow regulation.

In a cold water system, you’d use a globe valve where you need to regulate or balance flow on a branch or circuit, modeling and dialing in the amount of water that passes through. Ball valves are used where you need to isolate a section quickly for maintenance or to shut off a fixture or appliance.