Which component separates the boiler and non-boiler in a desuperheater?

In a desuperheater, the component that separates the boiler from the non-boiler side is indeed the shut-off valve. This valve is crucial in controlling the flow of steam or hot water into the desuperheater while isolating the boiler from other systems when needed.

The role of the shut-off valve is to prevent backflow and maintain safety and performance by isolating sections of the system during maintenance or emergencies. By shutting off the flow from the boiler, it prevents any pressure changes or thermal fluctuations from affecting the entire system, allowing for safe operation and maintenance activities.

Other components like pressure regulators, flow meters, and check valves have different functions; for instance, pressure regulators manage the pressure within the system, flow meters measure the quantity of fluid passing through, and check valves ensure that the flow direction is maintained, preventing backflow. While these components are essential in a boiler system, they do not serve the primary function of isolating or separating the boiler from the non-boiler side like the shut-off valve does.