Question 80Steam Plants - Assistant Engineer

The correct answer is D) internal desuperheater flange. The reason is that if boiler water chemicals are decreasing in one boiler and increasing in the other boiler, while both are steaming at normal rates, it indicates a leak in the internal components that allows water/steam to transfer between the two boilers. The most likely location for such a leak would be the internal desuperheater flange, which connects the superheater outlet to the steam header. The other options are incorrect because a leak in the feed water crossover line (A) would affect the water levels in both boilers, not just the chemical concentrations. Leaks in the superheater tubes (B) or economizer tubes (C) would not selectively transfer water/chemicals between the two boilers.