🔍 Key Concepts

• Thermostatic expansion valve (TXV) operation – how the sensing bulb, evaporator pressure, and spring pressure work together • Superheat adjustment – what ‘superheat’ is and why it’s adjusted in a refrigeration system • System stabilization – what happens to evaporator pressure and temperature right after an adjustment

💭 Think About

• Think about what changes inside the evaporator right after you turn the superheat adjustment stem on a TXV. Does the system instantly reach its new balance point? • Which option describes something that is actually necessary for TXV adjustment, versus extra procedures that are not normally required? • Consider the purpose of the sensing bulb and its charge: do you normally open, bleed, or reroute refrigerant in the system just to change a TXV’s superheat setting?

✅ Before You Answer

• Verify which choice mentions waiting for system conditions to settle before making more changes. • Eliminate any answer that requires unusual or unsafe handling of refrigerant for a routine TXV adjustment. • Confirm from your refrigeration theory that normal TXV superheat adjustment is done while the system is running under load, not with all refrigerant pumped down or rerouted.