... 404A 2. easy to change driving head and valve disc 3.MOP interchangeable expansion valve Characteristics:l Interchangeable orifice assembly. Construct is simple ... bolts, it is easy to change driving head and valve disc.l Stable superheat setting.l Can be supplied with ... stem anticlockwise one round,reduces superheat 0.3°C. interchangeable expansion valve, for R22,R134A,R407A,R507/404A(TCL/TRF)