Thank you for the site. However, i found an error in the description of how an Thermal Expansion Valve operates in the site ; the text says : 'In an expansion valve air conditioning system, refrigerant flow to the evaporator varies according to the pressure in the suction line (evaporator outlet). This is detected by a sensing bulb mounted on the line, and relayed to the expansion valve via a capillary tube '
The refrigerant flow to the evaporator is varied NOT according to the pressure in the suction line , but rather is it based on the pipe surface TEMPERATURE as sensed at the outlet of the evaporator (suction line) by the sensing bulb that is strapped in close contact to the suction line. Its purpose is to maintain a certain superheat value (typically 8-12 degrees f.) so all of the liquid refrigerant is evaporated as it makes it journey thru the evaporator as well as picking up additional heat (superheat) to ensure that only vapor refrigerant exits the evaporator... as a compressor is only designed to pump 100% vapor to avoid possible damage.