Solenoid valves are only used in low voltage refrigeration control systems, while modulation valves are used in high voltage applications.

A liquid line solenoid valve is either completely opened or closed, whereas a modulation valve is infinitely positioned according to the strength of the applied electrical signal.

Both valves operate in exactly the same manner, only the manufacturer's terminology is the differentiating factor.

A solenoid valve can only be installed in liquid lines.