Valve positioner having bypass component and control valve comprised thereof

Abstract

Embodiments of a valve positioner that can maintain operation of the control valve despite failures in one or more components. These embodiments reduce downtime by allowing in-situ repair to occur on the valve positioner. In one embodiment, the valve positioner incorporates a by-pass component, which can utilize control input signals (e.g., a 4-20 mA signal) to energize one or more components (e.g., a current-to-pressure converter) to cause the control valve to modulate fluid flow without the digital microprocessor and / or related components.

Description

technical field

[0001] The subject matter disclosed herein relates to control valves, and more particularly to embodiments of valve positioners for use in control valves. Background technique

[0002] Control valves regulate the transmission and distribution of fluids, such as liquids and gases. These devices are integrated in process control systems in various industries. An example of a process control system forms a control loop with remote sensors and other feedback elements to monitor process conditions (eg, temperature, pressure, etc.). In response to changes in process conditions, the control loop can generate signals that cause the control valve to alter fluid flow.

[0003] Many control valves incorporate valve positioners with digital components (such as microprocessors) capable of processing these signals. These digital components enable precise control and functionality of the control valve. Certain types of digital components can also expand the positioner's...

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