Which device provides overpressure protection for a closed refrigerant vessel?

• A. Snubber
• B. Pressure relief valve
• C. Vacuum valve
• D. Silencer

Answer: (B)

Overpressure protection for a closed refrigerant vessel is provided by a pressure relief valve. This device automatically opens when the internal pressure reaches a predetermined set point, venting refrigerant to a safe discharge path to prevent the vessel from exceeding its design pressure. It closes again after the pressure drops to a safe level, helping to avoid ruptures or explosions due to overpressure. Snubbers dampen pressure transients but don’t vent excess pressure. A vacuum valve prevents vacuum conditions and would not protect against rising pressure. A silencer reduces discharge noise but does not serve as the safety mechanism that relieves excess pressure.