Method for adjusting the pneumatic control valve of Fisher valve positioners

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　The Fisher valve positioner uses an I/P electrical converter to convert electrical signals into pneumatic signals. So what should we pay attention to during the conversion process? How should the conversion be carried out? The following will introduce it to you. 　　The I/P electrical converter of the Fisher valve positioner relies on air supply flowing through a constant-throttle orifice to the nozzle; when the drive signal from the electronic module decreases, the electromagnetic coil causes the armature/plate to move away from the nozzle, thereby reducing the back pressure and resulting in a decrease in the output of the pneumatic amplifier ； As the drive signal of the electronic module increases, this signal causes the armature to move, thereby controlling the coil of the I/P converter; the armature then moves the baffle closer to the nozzle, resulting in an increase in the back pressure at the nozzle. This in turn leads to an increase in the air pressure signal sent to the pneumatic amplifier, and consequently the valve positioner outputs a higher air pressure. 　　Note ①: The nozzle is prone to getting clogged at the site when the gas source is not clean. ②: When inspecting the I/P on-site, do not directly adjust the baffle, as this can cause deformation and lead to a decrease in accuracy. 　　Method for adjusting the pneumatic control valve of the Fisher valve positioner: 1. Loosen the lock nut ； 2. Adjust the gain control screw: turning it counterclockwise pulls the screw out, reducing the gain, decreasing the amplification factor of flow, and increasing stability ； Turning clockwise involves screwing in the adjustment screw, which increases the gain, raises the amplification factor of flow, and reduces stability. It should be noted during operation that if it is turned out too far, the gain will be too low, resulting in slow valve response and failing to meet the fast-opening requirement of the anti-surge valve ； Over-tightening results in high gain and fast response, but poor stability, which may cause oscillations in the anti-stall valve. 　　The above has introduced to you the operation steps of the electrical converter for Fisher valve positioners as well as the methods for adjusting pneumatic control valves. I hope this will be useful to you when you use them in the future.