PlantTriage Isolates Control Valve Mechanical IssuesPlantTriage provides accurate diagnostics of process and control equipment. Use these PlantTriage problem solvers to:
- Prepare for shutdowns
- Prioritize work on a weekly or monthly basis
- Diagnostics for daily problem solving
Several PlantTriage problem solvers are designed specifically for maintenance use. For example, we can take a look at valves that are sticking using the valve Stiction report. We can stabilize and improve flow control and reduce wear and tear on the valve and positioner by looking at sticky valves. By drilling down from the report you can get more detail, confirming the extent of the Stiction and its impact on the process.
During shutdown planning we’ll look at oversize valves to see if we can reduce process cycling and eliminate seat wear. Again, PlantTriage automatically finds and prioritizes which valves are oversized. It’s a good idea to look for oversize valves as you prepare for shutdowns or annual maintenance. Oversize valves tend to cycle a lot around the closed position creating excessive wear on the valve seats.
PlantTriage can identify valves that are being damaged due to poor tuning or inappropriate filters. Again, we can use the drill down to confirm the extent of the problem. Click on the loop name for more analysis. In this case we will remove a lot of the excessive valve travel by asking PlantTriage to design an appropriately sized filter for the instrument.
PlantTriage automatically identifies many different problems with instrumentation. Sensor spiking for example, is a great way to find instruments that are on the verge of failure. Look at sensor spiking on a daily or weekly basis and to identify instrument problems such as water in a sensing line or the failed liner on a mag flow meter.
Graphical treemaps can, for example, show the noise level on each instrument across the entire plant. You can very quickly pinpoint where the problems are.
The accurate, prioritized information in PlantTriage helps make your maintenance planning process very fast, efficient and effective.Back to PlantTriage home & videos
Over-sized valves create a number of problems: It is difficult to maintain tight control, and any valve problems are amplified. This problem solver lists valves that are likely to be oversized.
Corrective Actions to consider:
- Replace with a smaller valve
- Reduce upstream pump impeller size
Quickly find a complete list of all the oversized valves in your plant with this problem-solver.
The valves listed in this report are likely under-sized. Under-sized valves tend to run full open, and generally do not add a lot of value to the plant. If the process gain is less than 0.3, this is another sign the valve is too small. Corrective actions to consider:
- Replace valve with larger valve
- Replace trim with larger size
- Remove valve from service
- Reduce pump speed or impeller size
Sensors and instruments give early warning signs of failure. PlantTriage is continually monitoring sensors for these early warning signs. Control Loops that PlantTriage lists in this report are likely to have one of these issues:
- damaged sensor
- lost signal
- transmitter electronics failure
- sensor in a poor placement
- faulty wiring
PlantTriage notifies you of these issues before they become problems.
Valve Damage—Tuning, Problem Solver
Many signs of valve failure are apparent far in advance. PlantTriage lets you implement valve predictive Maintenance. The software automatically uncovers valves that are likely to experience problems due to excessive over-use. PlantTriage also recognizes the beginning signs of valve problems, long before a failure occurs. PlantTriage is scanning all the loops, all the time looking for problems.
Preventing a problem is worth much more than fixing a problem. Move toward prevention with PlantTriage.
The valves listed in this report are likely to be suffering damage due to incorrect controller tuning.
- Tune the loop with included tuning tools.
- Reduce or eliminate derivative action.
- Apply a filter to the Process Variable (use tuning tools to find the best filter).
- Identify & remove other sources of variation.
When a valve travels more than 3000%/day, this is usually an indication of poor tuning.
PlantTriage calculates exactly how much your control valves are moving in a day. Valves that move excessively due to poor tuning are more likely to require repairs. PlantTriage helps you avoid downtime by reducing valve wear. Applying PlantTriage tools will typically result in a 2 to 6 times reduction in valve travel.
In an on-site training class, a controls engineer learned how to use the
"Valves Damage—Tuning" Problem-Solver. After opening the
report for her plant she said:
"The valve at the top of this list has been replaced twice in the past six months. No wonder! It's a tuning problem."