Service manual

SYSTEM OPERATION
17
Indoor
Coil
Outdoor
Coil
Thermostatic
Expansion
Valve
Chatleff
Orifice
Assy
Typical Package Cooling or Package Gas
Expansion Valve/Check Valve Assy in Cooling Opera-
tion
Expansion Valve/Check Valve Assy in Heating Opera-
tion
Restrictor Orifice Assy in Cooling Operation Restrictor Orifice Assy in Heating Operation
Most expansion valves used in current Amana Heat Pump products use an internally checked expansion valve. This type
of expansion valve does not require an external check valve as shown above.
In the cooling mode the orifice is pushed into its seat forc-
ing refrigerant to flow through the metered hole in the cen-
ter of the orifice.
In the heating mode the orifice moves back off its seat al-
lowing refrigerant to flow unmetered around the outside of
the orifice.
Either a thermostatic expansion valve or restrictor orifice
assy may be used depending on model, refer to the parts
catalog for the model being serviced.