If the needle and seat assembly is excessively eroded, the valve cage assembly can be replaced. In replacing the original valve cage assembly rated at 1/2 tons, what would be the result if the replacement valve cage was oversized at 5 tons? Illustration GS-RA-07

Illustration GS-RA-07: the U.S. Coast Guard has not released this illustration.

Question

If the needle and seat assembly is excessively eroded, the valve cage assembly can be replaced. In replacing the original valve cage assembly rated at 1/2 tons, what would be the result if the replacement valve cage was oversized at 5 tons? Illustration GS-RA-07

Illustration GS-RA-07: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option C: The expansion valve would hunt excessively, alternately starving and overfeeding the evaporator coil.. Installing an excessively oversized valve cage creates severe capacity mismatch, causing the thermal expansion valve to hunt continuously as it overfeeds and starves the evaporator coil, inducing wild pressure and temperature fluctuations.