Expansion Block/Orifice Tube: Description and Operation

The fixed orifice tube system allows the compressed liquid to expand, by metering the liquid into the low pressure area of the evaporator.

The low pressure being created by the restriction of the fixed orifice tube and the suction of the scroll type compressor.

The liquid begins to change state by transferring from a high pressure liquid into a low pressure gas immediately it leaves the fixed orifice tube.