To control the flow of liquid to a delicate gauge, which type of valve should you use?

Using a needle valve to control the flow of liquid to a delicate gauge is ideal because needle valves are designed for precise flow regulation. They feature a long, tapering needle-like plunger that fits into a seat, allowing for fine adjustments of the flow rate. This makes them perfect for applications where maintaining a specific flow is crucial, especially when dealing with sensitive instruments like gauges that need careful monitoring.

In contrast, gate valves are typically used for on/off control rather than fine flow adjustment, making them less suitable in this scenario. Globe valves can offer good throttling capabilities but may not provide the level of precision needed for delicate applications. Check valves serve a different purpose altogether by preventing backflow rather than controlling flow, which does not meet the requirement of precise flow management for gauges. Therefore, the needle valve is the best choice for ensuring accurate measurements and conditions while protecting the integrity of the gauge.