The coil temperature measured at the expansion valve sensing bulb of an operating system is 10°F. The low side pressure with the compressor running as shown on the gauge illustrated indicates 15 psig. What adjustments or changes, if any, should be made to the system? Illustration GS-RA-16

Correct Answer: Option C — The expansion valve should not be adjusted, as the degree of superheat is within the accepted range.

At 15 psig, standard refrigerants yield a saturation temperature of approximately zero degrees Fahrenheit. Subtracting this from the 10°F bulb reading indicates 10 degrees of superheat, which falls well within standard marine operational parameters requiring no valve adjustment.