What is a self-help type regulating pneumatic valve? It is divided into which a few kinds?

self-reliance type regulating pneumatic valve is what? It is divided into which a few kinds?
on the classification of the type pneumatic valve adjustment:
type ZZY direct effect on pressure regulating pneumatic valve
type ZZV directly effect on decay pressure regulating pneumatic valve
ZZC direct effect of self-reliance type differential pressure regulating pneumatic valve
ZZYPII command unit operation model of self-reliance type pressure regulating pneumatic valve
ZZW self-reliance type temperature control pneumatic valve type ZZD
nitrogen sealed conditioning ZZFX type explosion-proof fire breathing pneumatic valve

self-reliance type pressure regulating pneumatic valve is introduced:
type pneumatic valve adjustment depend on themselves through the pneumatic valve within the medium's own pressure, temperature, as energy drive pneumatic valve work automatically, do not need the power converter and secondary instrument. Type of this kind of self regulating pneumatic valve use pneumatic valve the output feedback signal, Pressure, differential pressure, temperature) Tube through the signal to the actuator driven by pneumatic valve pneumatic valve opening change, achieve the purpose of regulating pressure, flow, temperature. The regulation of pneumatic valve is divided into direct effect and indirect effect type two kinds.
direct action type is also known as the spring load type, the structure inside the elastic element such as a spring, bellows, bellows type bulb, etc. , the principle of balance with the elastic force feedback signal.
indirectly regulating pneumatic valve type, add a command ( The forerunner of pneumatic valve) It play a role of feedback signal amplification and then through the actuator, drive the pneumatic valve pneumatic disc movement to change the purpose of the pneumatic valve opening.
if it is self-reliance type temperature regulating pneumatic valve, pneumatic valve of the export is the temperature sensor ( Temperature or package) Through the temperature sensor in medium heat bilges cold shrink drive actuators.
if it is self-reliance type flow control pneumatic valve, pneumatic valve outlet have an orifice ( Or other resistance devices) Introduced by orifice plate ends out differential pressure signal actuators.
if it is self-reliance type pressure regulating pneumatic valve, pneumatic valve feedback signal is the outlet pressure, by introducing actuator signal pipe.