Overview and technical analysis are given in illustrations focusing on the working principles of ventilators,in particular the three key components of conduit system(mixer,flow valve and exhalation valve),to provide helpful information for engineers or clinicians in relation to the design,maintenance and usage.

What is more,it can be used as the energy economizing air flow valve with long-distance and computer numerical control.

A kind of flow valve used in articulated dump truck is introduced.

Design and modeling of precise flux valve driven by piezoelectric ceramics;

The coordinating of large flow control valves and h igh pressure gel amp oules upon hydraulic supports are proposed in consideration of the variety of th e types of the above two things and their unfittness in use,which has brought inc o nvenience and even caused some loses in the process of manufacture,maintenance a nd standard management.

Distinguishes between balance valves and auto flow valves in application, through an analysis of their mechanism, applicability and project examples, and concludes that the balance valve should be used in the system where the resistance (water flow) balance is desired, and the auto flow valve should be used in the system where the constant water flow is needed.