Emerson reported Oct. 18 that a customer in China recently purchased the 3 millionth Fisher Fieldvue digital valve controller (DVC) sold over the past 30 years. The customer is using it in the pressure control valve in the membrane section of its water treatment plant.
- DVCs help regulate and monitor the opening and closing of control valves, and provide information about valve status and health. The company adds the top seven reasons for implementing Fisher instruments are:
- Fieldvue DVC enables remote monitoring of control valve position. Florida Power & Light installed it on 90 of its Fisher control valves control natural gas and steam flows associated with the turbines. Plant operators in the control room now receive valve position feedback, allowing them to verify the operation of each valve. Accurate control valve position enables tighter control to setpoint, increasing efficiency and improving operations.
- In offline mode, Fieldvue DVC can create a signature for a new valve that captures details on packing friction, air use, valve travel and other parameters—all of which can be compared to future valve signature test results. Often a comparison will quickly highlight developing issues, such as instrument misalignment, air supply issues and actuator leaks.
- It can proactively monitor valve performance while the valve is online and controlling the process, revealing if a valve is failing to reach commanded states or is exhibiting excessive air usage or abnormal friction. This information can alert maintenance staff of developing issues, and in many cases, diagnostic software can offer a list of possible causes, helping technicians quickly isolate and resolve the problem.
- It can detect trigger events, and capture valve profile and performance data before, during and after the event. This data may not keep an event from happening, but the information is often critical to quickly isolate the root cause of the problem and identify any failed components, so they can be repaired quickly.
- It’s often used in critical applications, such as on anti-surge and safety interlock valves. In these and other applications, DVCs enable partial stroke testing to ensure the valve will perform as required during abnormal conditions, and they can also be used for partial proof testing to extend intervals between required full proof testing.
- Historical data from the DVC can be combined with other upstream and downstream process information, such as surging pressures or swinging flows, to uncover operational problems. Fieldvue DVC can also expose how a valve is performing related to parameters and factors such as supply air pressure, positioner tuning, or mechanical sticking.
- It enables secure remote valve monitoring provided as a service by third-party experts. Based on instantaneous and trended data, it’s possible to detect abnormal conditions leading to many developing problems. However, this data is only useful if it’s gathered in near-real time and is accessible by specialists with the tools, skills and time to interpret it. Emerson provides these services with its Fisher ValveLink software to perform scheduled online testing of each valve as it operates.
Three end users gained the following benefits by using Fieldvue DVC:
- A herbicide plant in Iowa reduced annual maintenance costs by $230,000 by using Fieldvue DVC with advanced control valve diagnostics to transition its plant from reactive to predictive maintenance. In one case alone, the plant saved nearly $100,000 per hour by detecting and addressing a developing control valve issue before it shut down the unit.
- A paper mill in Louisiana was suffering routine boilers trips due to damper positioning problems. Upgraded Fieldvue DVC with advanced diagnostics eliminated these trips, avoiding losses of $18,000 per hour due to unscheduled outages.
- A combined cycle power plant was reworking all critical valves during every outage to maximize uptime when the plant returned to service. After upgrading to Fieldvue DVC and implementing diagnostic alert software, the plant focused their outage repair efforts more efficiently. The plant saved $68,000 in one outage alone and has experienced yearly cost reductions of $33,500. Similar programs in the company’s other plants have generated average savings of $1,200 per valve.
