Understandable valve diagnostics
Digital valve controllers can provide diagnostic data about the valve assembly. But how many users can correctly interpret the data they get?
Digital valve controllers can provide diagnostic data about the valve assembly. But how many users can correctly interpret the data they get? Are they getting understandable messages or confusing graphs and status bits that leave it unclear if something needs to be done immediately or during the next shutdown? And how about the emergency shutdown valve – is the safety action available? Valve controller vendors have different approaches on how to present the available data. Not all are really turning this data into information that delivers the message to the users. Of course, training can help to interpret the data, but in case special know-how is needed, the number of capable people will be limited to the trained specialists. Do they have time when a shutdown is planned – or is the specialist available if a problem arises late on a Saturday evening?
The Metso product family of digital valve controllers has been among those with state-of-the-art diagnostics for almost two decades. The amount of available data has been huge from the very beginning, so the latest developments have aimed to make all the data easy to use or even intuitive. This means packaging the data as information in a single view that makes the user pay attention to the right things, guide him/her to more information and provide easy guidelines for checking and corrective actions. This easy-to-use diagnostics is available for control valves, on-off valves and emergency shutdown valves, on top of a Metso actuator or any 3rd party actuator. Feedback from customers has been very positive!
In control applications, the screen includes a graphical presentation of the set point and actual point and supply pressure, as well as actuator channel pressures. The screen also shows the status of the valve assembly components with symbols that conform to the Namur NE107 standard, which are also intuitive. In cases where something is wrong, the user is provided with possible root causes and solutions. The condition of the valve assembly components is presented graphically by five different indices that summarize all the data collected. The same template is available for the safety valve as well. In the case of an emergency shutdown valve, the most important issue is to know that safety action is available. This is communicated with a simple traffic light. Also, the user is informed about the latest and the next partial stroke test, which is of course important for maintaining the required safety level.
In practice, valves often perform according to a known pattern. Therefore, a brief and easy check of the indexes and the suggested actions are of great help. When more correct maintenance decisions are made, a lot of additional savings from maintenance costs can be expected, as well as more effective reactions to possible problems. And in the case of an emergency shutdown valve, the availability of the safety action is known!
Niklas Lindfors works as Senior business manager for Valve controls business line and has long experience in valve diagnostics. He can be reached at firstname.lastname@example.org
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