The refrigeration system valve shown in the...

🔍 Key Concepts

• Identify the type of valve by its construction: a diaphragm with a remote sensing bulb (C) connected by a capillary tube usually indicates a thermostatic expansion valve (TXV). • Review what a TXV is designed to control in a refrigeration system: it modulates refrigerant flow based on conditions at the evaporator outlet. • Distinguish between what the valve controls directly (at the valve/evaporator outlet) versus what it influences indirectly (box temperature, compressor operation).

💭 Think About

• From the illustration, where is the sensing bulb (C) located in the system, and what line is it normally strapped to? How does that location affect what the valve responds to? • If the valve is responding to the temperature and pressure at the evaporator outlet, what specific property of the refrigerant there is being regulated? • Which of the answer choices describes something the valve itself can adjust at its own location, rather than something that would change later in the system as a side effect?

✅ Before You Answer

• Verify that a TXV’s main job is to maintain a certain condition at the evaporator outlet, not in the refrigerated box air or at the compressor. • Check which choice refers to a control variable that depends on both temperature and pressure at the evaporator outlet. • Eliminate any options that describe functions normally handled by separate controls, such as a box thermostat or low‑pressure/cycling controls on the compressor.

The refrigeration system valve shown in the illustration is used to directly control what? See illustration GS-RA-07.

the box temperature

the evaporator coil pressure

the 'on-off' cycling of the compressor

the evaporator superheat

🔍 Key Concepts

💭 Think About

✅ Before You Answer