Valve Positioners

Keep your control valves operating properly with valve positioners

Valve positioners play an important part in industrial plants. The instruments ensure control valves are properly communicating with the controlling elements of the plant. If the valve or actuator isn't in the correct position as designated by the input signal, the valve positioner intervenes and corrects the position. Valve positioners are available in pneumatic, electro-pneumatic and digital models.

The conditions of an industrial plant can often be hard on instruments. Control valve positioners typically need to endure extreme temperatures, corrosive environments, high vibration and poor air quality. Valve positioners are approved for certain environmental conditions depending on the model and features. When purchasing a control valve positioner, consider the following:

1. Determine the environmental conditions of your plant and the amount of time and service you're willing to devote to your valve positioner.

2. Know that digital valve positioners often require less maintenance because they have the ability to diagnose themselves.

3. Ensure the valve positioner has non-metallic housing if it will be exposed to corrosive conditions.

Buy valve positioners designed for hazardous environments

If you're planning to place the valve positioner in an area with extreme conditions, including high vibration and poor air quality, purchase a positioner designed to handle hazardous environments. Most control valve positioners are durable and corrosion resistant, but be sure the one you buy is approved for hazardous locations.

Find digital valve positioners

A digital valve positioner offers you convenience and time saved with its ability to diagnose itself as well as its valve and actuator. The positioner monitors the valve travel position and actuator pressure, which allows you to service the instrument only when its truly necessary.

Purchase control valve positioners that won't corrode

Because it's so critical industrial valve positioners function properly all the time, buy only instruments that won't be susceptible to corrosion. Most valve positioners manufacturers expect their instruments to be placed in corrosive environments, but don't assume every positioner is corrosion resistant.

• When ordering a valve positioner, consider your company's safety needs. Some valve positioners suppliers offer instruments with programmable shut-off features and additional function inputs that can be used to set a safety position or block the valve.

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