Which valve is primarily used where excess pressure drop is a concern?

The gate valve is the appropriate choice when excess pressure drop is a concern in a piping system. This type of valve is designed to allow or obstruct flow with minimal resistance, offering a straight-through, unobstructed passage when fully open. This design significantly reduces turbulence and pressure loss in the system, making gate valves ideal for applications where maintaining pressure is critical, such as in water supply or steam systems.

In contrast, globe valves, while excellent for throttling and flow regulation, can create a significant pressure drop due to their convoluted internal flow path. Check valves, designed mainly to prevent backflow, are not intended for managing pressure drop. Lastly, butterfly valves, while efficient in many applications due to their quick operation and space-saving design, generally provide more pressure drop compared to gate valves due to the disc's resistance as it rotates into the flow. This makes them less desirable in situations where minimizing pressure drop is crucial.