Adjust the pneumatic valve and role definition < / div >

1: ventilation pneumatic valve lever downward movement is positive, whereas for the reaction.
note: positive and negative effects and KaiQi closed is not a concept, should pay attention to when setting adjustment circuit.
are generally the same as the positive and negative effects of the actuator, knew the positive and negative effects of the actuator, also knew the positive and negative function of positioner:
2: take the handwheel adjustment pneumatic valve and pneumatic adjustment of pneumatic valve, pneumatic valve handwheel mainly used in pneumatic valve control gas path fault manual switch. Gas-off pneumatic valve handwheel switch to different.
3: positive and negative effect refers to the way of pneumatic regulator has nothing to do with pneumatic regulating pneumatic valve, but for the positive role of pneumatic regulator usually distribution in the regulating pneumatic valve; Reaction of pneumatic regulator usually distribution open pneumatic valve adjustment.
4: pneumatic pneumatic valve positioner can control the positive role of pneumatic valves?
can, by changing the pneumatic pneumatic valve film head inlet direction can be achieved, if the air from the top into the positive interaction, then air from the bottom into is negative.
5: adjust the action of the pneumatic valve way only when choosing pneumatic actuators, the role of way through positive and negative effect and the positive role of pneumatic valve actuator portfolio formation. There are four that are positive (combination Gas closed type) , positive and negative, Gas type) And anyway, Gas type) And reflect ( Gas closed type) , through these four combination way have the function of regulating pneumatic valve open and close two kinds. For the choice of the ways of regulating pneumatic valve function, mainly from three aspects: a) Process safety; b) The characteristics of medium; c) Ensure product quality and economic loss is minimal.
6: gas pneumatic valve and gas breath what is the definition of a fixed valve?
force increases, the push rod downward movement is acting actuators; Signal pressure increases, the push rod upward movement called reaction type actuator. Pneumatic valve components and actuator pneumatic valve, regulating qi pneumatic valve is as the pressure signal, gradually open, no signal, pneumatic valve closed; Gas breath valve is as the pressure signal, gradually closed, no signal, pneumatic valve in the fully open position.
7: angry ( The signal pressure) Then open the pneumatic valve is called gas drive, pneumatic valve, pneumatic valve was once the signal interrupt return to the original state (it Closed) 。 Have spirit, The signal pressure) To close the pneumatic valve is called air breath valve, pneumatic valve was once the signal interrupt return to the original state (it Open) 。
: 8: gas pneumatic valve: open to instrument the wind when open the air breath powered valve pneumatic control valve: give wind instrument control pneumatic valve shut accident: meter wind sudden stops and pneumatic control valve back to the state of nature that is fully open, namely gas breath valve ( The wind off pneumatic valve) Instrument: accident, the wind suddenly stopping control pneumatic valve return to natural state is seated, namely gas drive pneumatic valve ( The wind open pneumatic valve)
9: adjust the pneumatic valve gas, gas close pneumatic valve selection, mainly according to the needs of production and safety requirements; Principle is to be interrupted when the signal pressure, should be able to ensure the safety of the process equipment and production. If pneumatic valves in the fully open position high safety, choose the gas drive, pneumatic valve, on the contrary, the persons to be gas type pneumatic valve closed.
10: FC and FO the difference between FC is the failure of pneumatic valve closed FO is failure of pneumatic valve open
11: pneumatic control valve of gas, gas closed in P& ID in the diagram is with loss of air pressure condition of pneumatic valve shut or open. Gas open of pneumatic valves, with FC at the bottom of the pneumatic control valve, pneumatic valve rod with a down arrow said. Gas of the pneumatic valve closed, under the control of pneumatic valve tagging FO, pneumatic valve rod with the up arrow said.