1) The functions and application fields must be basically the same. It is nonsense to compare cow's head with horse's leg.

2) There are better cost performance or excellent performance but not much price increase. The performance is not bad, but the price is obviously low.

The performance should be generalized, including persistence, environmentality, and so on.

The price should take into account not only the cost of research and development, design and manufacturing, but also the cost of replacement and replacement.

Therefore, one technology is advanced and can replace the other, which requires a comprehensive and realistic comparison of performance data obtained through actual testing and comparison of various costs. It's not enough to compare one point. For example, although the servo valve's repeatability, linearity and so on is obviously superior to the electric proportional valve, its application quantity, scope is still far inferior to the electric proportional valve. It is not only the complex structure of the servo valve, manufacturing costs, but also the pollution sensitive issues.