Expansion Block/Orifice Tube: Description and Operation

The restrictor 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.

NOTE: Insert the restrictor so that arrow -A- points to evaporator