In which situation are shut-off valves not required for a heat exchanger?

Shut-off valves are typically used in systems to isolate components for maintenance, service, or emergency situations. However, when a heat exchanger is integral with the boiler, it is considered a single assembly. In this case, the heat exchanger operates as part of the boiler's primary system, and the need for separate shut-off valves is diminished because the entire unit can be isolated through the boiler's existing controls.

Moreover, having separate shut-off valves in integral systems may introduce unnecessary complexity and could create points of failure. In situations where the heat exchanger is not designed to be removed from the boiler without dismantling the entire unit, the necessity for individual shut-off valves becomes irrelevant.

In contrast, during maintenance, separate shut-off valves allow for the isolation of the system, and in instances when equipment is external or includes pumps, the need for isolation remains crucial for safety protocols and operational efficiency.