Which of the following illustrated expansion valves is designed to maintain a constant evaporator pressure rather than a constant evaporator superheat? GS-RA-24

Illustration GS-RA-24: the U.S. Coast Guard has not released this illustration.

Question

Which of the following illustrated expansion valves is designed to maintain a constant evaporator pressure rather than a constant evaporator superheat? GS-RA-24

Illustration GS-RA-24: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option C: C. Evaporator Pressure Regulators (EPR), represented by letter C, throttle vapor leaving the evaporator to maintain a constant minimum evaporating pressure regardless of fluctuating thermal loads, preventing coil temperatures from dropping below freezing when undesirable.