What are the two types of valves required on the feed water of a boiler?

The correct answer is that the two types of valves required on the feed water of a boiler are a check valve and a globe valve.

A check valve is essential in a boiler system as it allows fluid to flow in one direction and prevents backflow. This is crucial for ensuring that the feed water does not return to the supply line, which could harm the system or create unsafe conditions. The presence of a check valve helps maintain consistent pressure and flow within the system, ensuring proper operation of the boiler and preventing potentially dangerous situations.

The second type of valve, a globe valve, is used primarily for regulating flow within the system. Its design allows for precise control over the amount of feed water entering the boiler, making it easier to manage operational parameters and efficiency. Globe valves are widely recognized for their ability to perform well in throttling applications, which is beneficial for maintaining the appropriate water level and pressure in the boiler.

Together, these two types of valves contribute to safe and efficient boiler operation, making them standard practice in high-pressure piping systems. Other combinations, such as those including gate or ball valves, do not provide the same level of necessary functionality for controlling flow direction and pressure in this specific context.