Trane screw machine and centrifuge accessories

Trane screw machine solenoid valve and coil Valve VAL12407 COL27493 Electronic expansion valve some people will use this thing, but for some ordinary people, it is a strange thing, so electronic expansion valve, how does this thing work, what effect does electronic expansion valve have! About these questions and small make-up together to look down! Electronic expansion valve some people will use this thing, but for some ordinary people, it is a strange thing, so electronic