What is the function of a metering device in a refrigeration system?

What is the function of a metering device in a refrigeration system?

• A. It meters the flow of liquid refrigerant to the evaporator, controlling superheat and evaporator capacity.
• B. It increases the refrigerant pressure before the evaporator.
• C. It stores liquid refrigerant upstream.
• D. It cools the refrigerant after the evaporator.

Answer: (B)

The metering device’s job is to throttle the refrigerant, lowering its pressure before it reaches the evaporator. By reducing pressure on the high‑pressure liquid, it allows the refrigerant to begin boiling and absorb heat in the evaporator. This throttling also regulates how much refrigerant can enter the evaporator, matching the evaporator’s capacity to the system load and helping control the superheat of the vapor leaving the evaporator. It does not increase pressure, store liquid upstream, or cool the refrigerant after the evaporator.

The metering device’s job is to throttle the refrigerant, lowering its pressure before it reaches the evaporator. By reducing pressure on the high‑pressure liquid, it allows the refrigerant to begin boiling and absorb heat in the evaporator. This throttling also regulates how much refrigerant can enter the evaporator, matching the evaporator’s capacity to the system load and helping control the superheat of the vapor leaving the evaporator. It does not increase pressure, store liquid upstream, or cool the refrigerant after the evaporator.