Valve Positioners Flexible in Any Position — Valve Positioners as Versatile Multi-Taskers
An extremely broad range of process applications requires field devices with a high degree of flexibility. Likewise, the issues of standardization and simple stock management are becoming increasingly important. And the devices must meet the normal everyday requirements: easy to operate and capable of being used universally, while requiring minimal time and cost for maintenance. So how does this apply to automated valves?
Control valves that influence the flow of process fluids are a fundamental component of every automated process plant. They are controlled by many different types of actuators, including hydraulic and electric designs, but the majority have pneumatic actuators. This is where the widest range of demands occurs — not only on the actuator itself and the valve, but particularly on the positioner. The latter is the field component that transforms a collection of hardware into an automated application and it has to provide for:
- the widest variety of actuator movements and ranges;
- manufacturer-specific standards;
- special applications;
- controlled or “simple” open/close operation;
- fast and easy commissioning;
- short travel times but with precise control;
- the ability to proactively receive information about wear and the state of the application.
Does one need the widest range of devices or even manufacturers to meet these various requirements for a positioner? Does this mean that the two different perspectives mentioned above, as well as all these additional requirements, cannot be addressed through a single solution? The answer is emphatically no, as the Sipart PS2 positioner demonstrates.
Easy Mounting and Initialization
One great advantage of the Sipart PS2 positioner is its universal usability. This in turn requires a high degree of flexibility and mounting options for various actuator and valve applications. This requirement has been addressed by providing more than 400 mounting kits. These enable the device to be mounted on a very wide range of actuators, both standardized — such as part-turn actuators according to VDI/VDE 3845 and linear actuators according to IEC 60534-6-1 (Namur) — and also on non-standard, manufacturer-specific actuators.
The subsequent commissioning takes just a few minutes. This is made possible through the simple and direct push-button operation and display, plus an adjustable friction clutch which ensures smooth setup without time-consuming dismounting and remounting of the device. The positioner learns the application properties automatically, and adjusts itself to the relevant requirements.
If changes develop over time as a result of environmental influences or wear, the positioner adjusts itself to the new requirements and informs the operator about the changes through alarm messages. This is done via Hart, Profibus PA, Foundation Fieldbus, or digital output.