Answer :
Final answer:
A closed feedwater heater is equipped with a safety valve to protect from excessive pressure by releasing the excess once it hits a certain level, ensuring the safety and integrity of the equipment. The correct answer is a).
Explanation:
A closed feedwater heater is normally equipped with a safety valve to protect the shell from excessive pressure. The safety valve is a critical component designed to prevent equipment damage and ensure safety by releasing excess pressure once it reaches a certain threshold.
In contrast, a check valve is used to prevent backflow and does not release pressure, a pressure regulator controls the pressure level within a system but does not necessarily act as a safety device, and a thermostat regulates temperature without directly controlling pressure levels.
Safety valves are an essential part of the valve system for P&IDs and are required for all gas, steam, air, and liquid tanks under US law for pressures greater than 3 psig. These valves are designed to open and allow fluid to escape, thereby reducing the pressure within the vessel to prevent potential equipment failure or hazards.
