A/C condenser
The condenser transfers heat from the compressed refrigerant gas to the outside air which causes the refrigerant to change state from a gas to a liquid.
Scheme 3
The restrictor (orifice tube) restricts and controls refrigerant flow to the evaporator thus lowering refrigerant temperature and pressure.
Upstream of the restrictor, the refrigerant is hot and under high pressure. Downstream of the restrictor, the refrigerant is cold and under low pressure.
A strainer located upstream of the restrictor filters out any dirt or particles. Another strainer located downstream of the restrictor atomizes the refrigerant before it enters the evaporator.
Scheme 4
Note. Insert the restrictor so that arrow -A- points to evaporator.