What valve is the main shutoff valve for the entire system and can be found at the liquid outlet of the receiver

• A. The King valve
• B. Main shutoff valve
• C. Isolation valve
• D. Service valve

Answer: (A)

The main valve that shuts off everything in the system is the king valve. It sits at the liquid outlet of the receiver so you can stop all flow from the receiver to the rest of the plant in one action. This valve is sized and built to handle full system pressure and to be operated quickly for safe shutdowns or maintenance. When the king valve is opened, liquid can move downstream to feed the entire system; when it’s closed, no refrigerant leaves the receiver, effectively isolating the whole plant. Other valves like isolation valves or service valves serve more specific purposes (isolating a section or providing access for service), but they don’t provide a single point of shutdown for the entire system like the king valve does.