rotork YT-1200 Series, Руководство по эксплуатации продукта

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Pneumatic Positioner
YT-1200 series Product Manual
Ver. 1.18
21
3.2
Rotary Positioner
Fig. 3-2: Rotary positioner with an actuator
When INPUT SIGNAL PRESSURE increases to open the valve, the bellows stretches and pushes
②
the flapper to the opposite side of
③
the nozzle. The gap between
③
the nozzle and
②
the flapper
becomes wider and from inner part of
④
the pilot, air inside
⑨
the chamber is exhausted through
③
the nozzle. Due to this effect
⑤
the spool moves to the right. Then,
⑦
the seat which was blocked
by the poppet pushes
⑧
the poppet away and supplied pressure (air) goes through
⑦
the seat and
OUT1 Port and enters into
⑩
the chamber of the actuator through OUT1. Then
⑩
chamber’s OUT1
pressure will increase and
⑪
the actuator’s stem will rotate and through
⑫
the feedback shaft,
actuator’s rotating motion will be transferred to
⑬
the cam. This motion will then rotate
⑭
the span
lever and pull
⑮
the span’s spring. Once it reaches to given input signal,
⑮
span spring’s pulling force
and force of
①
bellows will be balanced and move
②
the flapper back its original position to reduce
the gap between
③
the nozzle. The amount of air being exhausted through
③
the nozzle will reduce
and
⑨
chamber pressure will increase again.
⑤
Spool will move back to its original position on the left
and
⑧
the poppet will also move in same direction blocking
⑦
the seat to stop the air coming into the
⑩
chamber through the SUPPLY. As a result, the actuator will stop operating and the positioner will
return to its normal condition.