Variable refrigerant expansion device with pressure relief

A refrigerant expansion assembly, and method of operation, for use in a vehicle air conditioning system is disclosed. An orifice channel connects an orifice inlet port to an orifice outlet port and includes a valve seat. A variable orifice assembly is mounted in the orifice channel and includes a fixed orifice passage extending axially through a variable orifice body having a sealing flange that can seal against a valve seat via an orifice spring. An orifice bypass valve includes a check ball biased against a ball seat by a bypass spring and selectively allows some of the refrigerant to bypass the variable orifice assembly. The refrigerant expansion assembly may also include a burst disk downstream of the variable orifice assembly.