Which of the following is NOT a valve found on a boiler?

A throttle valve is not typically found on a boiler system. In general, boiler systems utilize valves that are crucial for safety, flow control, and maintenance of the steam and water within the system.

Ball valves, gate valves, and butterfly valves are commonly used in boiler applications.

• Ball valves provide reliable sealing and are often used for on/off control. Their quick operation and minimal pressure drop make them ideal for regulating flow in boiler systems.

• Gate valves are primarily used for on/off control as well, allowing for a straight-line flow of fluid with minimal resistance. They are often placed in high-pressure areas of boiler systems for isolating specific sections.

• Butterfly valves are favored in systems that require quick operation and are effective for throttling flow as well as being lightweight and compact. They can also result in lower pressure drops in certain applications.

In contrast, throttle valves are typically used for regulating the flow rate and pressure in different engineering applications, but they do not serve as a primary valve type in standard boiler setups. Therefore, the identification of the throttle valve as the option that is not found on a boiler is justified.