Answer :
Final answer:
A closed feedwater heater is protected from excessive pressure by a pressure relief valve, which serves as a safety mechanism to automatically prevent overpressure conditions by releasing excess fluid. So the correct answer is Option A.
Explanation:
A closed feedwater heater is a crucial component of power plants and industrial processes, providing heat to water before it enters boilers or steam generators. For safety purposes, such systems must be equipped with mechanisms to prevent catastrophic failures due to excessive pressure build-up. A pressure relief valve is the device commonly employed to fulfill this function. It acts as a failsafe, automatically opening to release pressure when it exceeds a preset threshold, thus safeguarding the integrity of the system against potential overpressure scenarios.
Pressure relief valves are a fundamental safety feature in a myriad of applications, particularly in high-pressure environments such as those found in the petroleum refining industry. They are designed to divert fluid to an auxiliary passage or vent it to the atmosphere, depending on the process requirements. An overpressure event could be triggered by a variety of factors such as loss of heating or cooling, mechanical failure, or improper draining, making the installation of pressure relief valves a critical aspect of process control and safety.
In contrast, while important for monitoring and controlling the system, components such as temperature sensors, flow control valves, and pressure gauges do not directly release excess pressure. Rather, they provide valuable data which can be used to adjust the process or actuate other devices to maintain safe operating conditions. The correct option to protect the shell of a closed feedwater heater from excessive pressure is (a) Pressure relief valve.
