From the perspective of balance, expansion valve can be divided into internal and external balance type.
The internal balance pressure is taken at the inlet of the evaporator and the external balance pressure is taken at the outlet of the evaporator.
The internal balance expansion valve is usually used in domestic air conditioning, the cooling quantity of automobile air conditioner is generally larger, and the pressure loss of refrigerant in evaporator is larger, So we just use the external balance.
From the perspective of superheated regulatory structure,expansion valve is divided into internal mode and external mode.
The internal mode can only be adjusted before the air conditioning system is installed. Its advantages are small size, compact structure and suitable for bulk molding products.
The external mode can be adjusted according to the situation on the air conditioning system, which has great flexibility, but the increase of the parts makes the size and weight much larger.