🔍 Key Concepts

• Thermostatic expansion valve (TXV) function in a refrigeration/air conditioning system • Difference between internal adjustments (control characteristics) and simple maintenance tasks • Manufacturer’s recommendations on what is considered service/maintenance vs. repair or recalibration

💭 Think About

• Which of these options involves simply cleaning or restoring flow without changing how the valve is calibrated to control superheat? • Which options would normally require factory/service‑shop equipment or specialized procedures rather than routine shipboard maintenance? • Think about what a watchstander or shipboard engineer is usually allowed to do on a TXV without voiding the warranty or altering design settings.

✅ Before You Answer

• Identify which choices would change the control characteristics (rate/proportional action or charge) of the valve. • Ask: which task is clearly a routine, low‑risk maintenance job you could reasonably do in place? • Confirm which parts of a TXV are usually sealed or factory‑set and therefore not normally adjusted or recharged on board.