🔍 Key Concepts

• Discharge pressure regulating valve location in the system (between compressor and condenser) • Relationship between ambient temperature, condenser pressure, and required head pressure for TXV operation • Effect on the system when head pressure becomes too low versus when it becomes too high

💭 Think About

• When the outside (ambient) temperature drops very low, what tends to happen to the condenser pressure and the compressor discharge pressure? • Why does the TXV (thermostatic expansion valve) need a certain minimum pressure difference between the liquid line and the evaporator to operate correctly? • Looking at the illustration, does this valve seem to be throttling flow to raise pressure, or relieving pressure to lower it?

✅ Before You Answer

• Identify on the diagram which side of the valve is connected to the compressor discharge and which side is connected to the condenser inlet. • Decide during which condition (high ambient vs low ambient) the condenser would naturally run at very low pressure if it were not controlled. • Confirm whether the valve’s job is to maintain a minimum head pressure or to prevent excessive head pressure before choosing an option.