Which type of valve is commonly used in boiler systems?

In boiler systems, a check valve is specifically used to allow fluid to flow in one direction while preventing backflow. This functionality is crucial in maintaining pressure and ensuring that the system operates efficiently without the risk of damaging components from reverse flow. Check valves automatically close when the flow stops or reverses, thereby protecting the boiler and its associated systems from potential hazards.

Gate valves, while used in boiler systems to start or stop flow, are not typically preferred for controlling flow direction due to their design that does not prevent backflow. Ball valves provide quick shut-off capabilities and allow for good flow control, but they too are not primarily designed to prevent reverse flow. Butterfly valves can control flow as well, but they are usually employed where space is limited and are not specifically designed for the same protective function as check valves in a boiler system. Thus, the check valve's role as a backflow prevention mechanism makes it the most suitable choice for use in boiler systems.