I has been decades since I worked at Dow Chemical and UTC aerospace in the fuel pumping engineering groups. In the 70's the valves at Dow were powered by air pressure as were many other instruments. Motors were controlled with on/off relays/breakers. That has all changed. Those relays/breakers were being mounted on the ceiling of the block houses to make room for motor drives in existing plants. And I am sure air power has been replaced by electronics. I was happening in the products and test stands at the aerospace company over the 20 years.
A direct replacement for an air driven piston to operate a valve is a solenoid. But the power needed is significant considering over 100 psi air drives a valve over an inch in diameter. So the best choice is a motor driving through gear reduction that valve. The motor is sized for the worse case for force needed and time response. The cost of the motor and the drive are directly proportional to power needed for the worse case. Motors for a first order of magnitude cost linearly with torque. The motor drive cost goes in steps since the semiconductors needed go in steps. Cost ramps us quickly to a quasi linear rate. The Grundfos valve is very small and at the low end of the electrical power needs, thus lower cost point also.
The types of application for such smaller system include small building heating system and water systems, the cooling and hydraulic systems for plastic injection machines, and the like machines.
