In scheduled systems, what is the maximum number of 1" sprinkler heads that can be taken off?

In scheduled systems, the maximum number of 1" sprinkler heads that can be disconnected or removed without compromising the system's integrity is often defined by the specific hydraulic calculations and performance requirements established by design criteria.

In this case, the correct answer indicates that the system can handle the removal of up to two 1" sprinkler heads without risking the performance or function of the remaining system. This limitation ensures that even with those two heads taken out of service, the water supply and distribution capabilities remain sufficient to cover the areas intended to be protected.

Removing more than two heads could lead to inadequate coverage and weakening of the firefighting capability, as the remaining sprinkler heads would have to accommodate for the loss, potentially exceeding their designed flow capacity. Thus, the correct option reflects both the safety regulations and practical limits established to maintain effective sprinkler system operations.