Which option is NOT a TXV operating pressure?

Which option is NOT a TXV operating pressure?

• A. Condenser pressure
• B. Evaporator pressure
• C. Suction bulb pressure
• D. Spring pressure

Answer: (A)

Condenser pressure isn’t part of the TXV’s control loop. The thermostatic expansion valve meters refrigerant based on pressures and temperatures on the low side: the evaporator (suction) pressure that the valve is trying to regulate, the pressure in the sensing bulb (which mirrors the evaporator outlet temperature), and the spring pressure inside the valve that provides the baseline opposing force. The TXV sits between the evaporator and the compressor on the low-pressure side, so high-side condenser pressure has no direct role in how the TXV opens or closes. By balance of bulb pressure and spring pressure, the valve throttles refrigerant to maintain the desired evaporator conditions.

Condenser pressure isn’t part of the TXV’s control loop. The thermostatic expansion valve meters refrigerant based on pressures and temperatures on the low side: the evaporator (suction) pressure that the valve is trying to regulate, the pressure in the sensing bulb (which mirrors the evaporator outlet temperature), and the spring pressure inside the valve that provides the baseline opposing force. The TXV sits between the evaporator and the compressor on the low-pressure side, so high-side condenser pressure has no direct role in how the TXV opens or closes. By balance of bulb pressure and spring pressure, the valve throttles refrigerant to maintain the desired evaporator conditions.