Refrigerant Expansion Assembly with Pressure Relief

A vehicle air conditioning system comprising:

• a refrigerant compressor;
• a condenser configured to receive a refrigerant from the refrigerant compressor;
• an evaporator;
• and
• a refrigerant expansion assembly including an orifice inlet port that receives the refrigerant from the condenser, an orifice outlet port that directs the refrigerant to the evaporator, an orifice channel extending between the orifice inlet port and the orifice outlet port and including a fixed orifice, an upstream bypass channel extending at a non-parallel angle from the orifice channel between the orifice inlet port and the fixed orifice and including a ball valve seat, and a downstream bypass channel extending at a non-parallel angle from the orifice channel between the fixed orifice and the orifice outlet port;
• a bypass valve flange extending from the main body and forming a bypass chamber therein, the bypass chamber connected to the upstream bypass channel and the downstream bypass channel, with the ball valve seat adjacent to the bypass chamber;
• a check ball mounted in the bypass chamber adjacent to the ball valve seat;
• and a spring operatively engaging the check ball to bias the check ball into the ball valve seat, whereby when a refrigerant pressure in the upstream bypass channel exceeds a first predetermined pressure threshold, the check ball is moved away from the ball valve seat against the bias of the spring.

A method of operating a vehicle air conditioning system having a refrigerant expansion assembly, the method comprising the steps of:

• (a) directing a refrigerant through an orifice inlet port, an orifice channel, having a fixed orifice, and an orifice outlet port prior to directing the refrigerant into an evaporator;
• (b) applying a refrigerant pressure to a check ball, against a bias of a spring, upstream of the fixed orifice;
• (c) pushing the check ball against the bias of the spring into an open position when the refrigerant pressure exceeds a first predetermined pressure threshold, allowing the refrigerant to flow past the check ball through a bypass chamber to thereby bypass the fixed orifice;
• and
• (d) the spring biasing the check ball into a closed position when the refrigerant pressure drops below the first predetermined pressure threshold, thereby forcing all of the refrigerant to flow through the fixed orifice.