External equalizing line should be installed downstream of the thermostatic expansion valve at?

External equalizing line should be installed downstream of the thermostatic expansion valve at?

• A. Diaphragm
• B. Compressor
• C. Receiver
• D. Condenser

Answer: (A)

The external equalizing line is used to feed the evaporator outlet pressure back to the expansion valve so it can compensate for pressure drop across the evaporator and keep the valve’s control stable. It must be connected to the diaphragm side of the thermostatic expansion valve—the part where pressure acts to move the diaphragm and balance the sensing bulb signal. By tying the line to the diaphragm chamber, the valve senses the true evaporator outlet pressure and adjusts flow correctly, even when there’s significant pressure drop along the coil. Connecting the line to other components (like the compressor, receiver, or condenser) would not provide the correct evaporator-side signal and would degrade superheat control.

The external equalizing line is used to feed the evaporator outlet pressure back to the expansion valve so it can compensate for pressure drop across the evaporator and keep the valve’s control stable. It must be connected to the diaphragm side of the thermostatic expansion valve—the part where pressure acts to move the diaphragm and balance the sensing bulb signal. By tying the line to the diaphragm chamber, the valve senses the true evaporator outlet pressure and adjusts flow correctly, even when there’s significant pressure drop along the coil. Connecting the line to other components (like the compressor, receiver, or condenser) would not provide the correct evaporator-side signal and would degrade superheat control.