Digital valve controllers (dvc) are vulnerable to interruptions in the power supply. Given the remoteness of many pipeline installations, this consideration is often cited as a weakness. Moreover, a pneumatic controller is not affected by lightning, which has caused countless failures in electronic instrumentation installed on pipelines. Last but not least, pneumatic controllers do not introduce an ignition source and are thus rated non-incendive, so they can be used in Class 1, Division 1 environments without a second thought. Digital valve controllers (dvc) are fast replacing pneumatics as they have in countless refinery and chemical plant applications, but users have to pay attention to appropriate housing, mounting and other considerations
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