Which of the following illustrated thermal expansion valves would be appropriate to use on an evaporator coil with a 2 psi pressure drop, where externally adjustable superheat and a replaceable power element are both desired? Illustration GS-RA-06

Correct Answer: Option B — B

Internal equalizer valves are restricted to evaporators with negligible pressure drop, whereas externally equalized thermal expansion valves compensate for evaporator pressure drops exceeding 2 psi while offering adjustable superheat and replaceable power elements.