Excessive pressure in a low-pressure chiller is relieved by which of the following?

In a low-pressure chiller, excessive pressure is effectively managed through the use of a rupture disk. A rupture disk is a safety device designed to provide a reliable pressure relief mechanism by rupturing at a predetermined pressure to prevent the system from exceeding safe operational limits. When the pressure within the chiller rises too high, the disk bursts, allowing the pressurized refrigerant to escape safely, thereby preventing potential damage to the chiller components or any safety hazards.

This device is particularly important in low-pressure systems, where maintaining the integrity of the system is crucial, as these systems often operate under specific pressure ranges. The rupture disk is a passive device that does not require external power or control signals to operate; it reacts solely to the pressure it encounters.

Other components like pressure relief valves may be used in various applications, but they are designed to operate dynamically and may not be as ideal for the specific scenario of excessive pressure in low-pressure chillers as a rupture disk. The expansion valve and condensing unit serve different functions within the refrigeration cycle and do not engage directly in pressure relief, thus reinforcing the importance of the rupture disk in handling excessive pressure situations effectively.