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Control Valve Maintenance: Proactive Strategies for Long-Term Performance
Control valves are, if anything, proof that even small things can make a huge difference in life. They’re tasked with regulating the flow of fluids and gases along a network of pipes, remotely operated via a remote system such as a proportional-integral-derivative (PID) controller. Their proper function is paramount in keeping industrial facilities and utilities running.
However, control valves are often points of failure in expansive systems. Whether it’s a faulty actuator or signs of corrosion, a single problematic valve can force a critical machine to stop working for hours, if not days. A recent scenario occurred in the UK, where residents of two towns were without water for several hours after a valve unexpectedly shut down.
Undoubtedly, the timely repair and maintenance of these valves should take priority. Without it, a factory or utility service risks more complications and costly downtimes for the machinery or system. Below are some proactive strategies to ensure long-term performance and reliability.
Avoid a proactive-heavy mindset
As counterintuitive as this tip may sound, it’s important to note that proactivity isn’t a one-size-fits-all solution to mechanical problems. To know why, you must understand what a proactive approach entails, starting with a manufacturer’s point of view.
Unexpected downtimes are money pits for industrial manufacturing, costing USD$50 billion annually in lost productivity, revenue, and customer satisfaction. According to expert analysis, the firefighting method of tackling problems isn’t working well for factories and plants. As a result, owners are resorting to more advanced approaches, which are the following:
- Preventive maintenance: conducting routine inspections, resolving minor issues
- Predictive maintenance: performing equipment data monitoring and assessment
- Proactive maintenance: addressing potential risks before they manifest
While proactive maintenance may seem the most effective of the three, it isn’t intended to fix equipment failures when they occur. The other two also have downsides of their own, ranging from increased costs to hiring a data analyst. Adopting all three is necessary for optimum results.
As with any other component, control valves are subject to these kinds of maintenance. The rigors of regulating fluid flow will wear out even the highest-quality valves in the market. A routine inspection, close data monitoring, and risk assessment can help determine if it’s time to swap for fresh ASCO valves or the like.
Exercise valves annually
Over time, debris and deposits will inevitably build up inside the valve, affecting its ability to control fluid flow. Think of it as fat deposits along a blood vessel or one of the heart’s valves constricting the bloodstream, which leads to various health problems.
Just as exercise (and a healthy diet) is key to getting rid of fat in blood vessels, it’s also vital for control valves. Valve exercising involves repeatedly opening and closing one in various settings for a set number of rotations. A recommendable routine includes the following:
- Rotate toward closing 5 to 10 times.
- Rotate the opposite way 2 to 3 times.
- Repeat the above steps until full closure.
- Slightly open the valve to clean out deposits.
- Completely close the valve.
The practice is commonplace among water utilities, especially in the US, as per guidelines by the American Waterworks Association. Critical valves should undergo exercise at least once a year, while non-critical ones should be tested for wear and tear just as frequently. It can be done alongside systematic flushing.
Implement a VAMP
A valve asset management program (VAMP) is a must-have for machinery and other assemblies that use dozens of control valves. It keeps track of every valve in operation and their location in the system, organizing and displaying information like the following:
- Maintenance and inspection records
- Performance and test evaluation reports
- The criticality of a specific valve
- Diagrams of the valve and nearby systems
- Images of the control valve in question
- Other pertinent notes
A VAMP can be as simple as a manual spreadsheet, though experts advise investing in software to reduce the risk of costly errors. By keeping close tabs on all control valves in real time, plants and utilities can schedule maintenance routines such as lubrication and repairs ahead of time, proactively lowering the chance of unscheduled downtimes.
Another sound tip is to employ a VAMP based on ISO 55001:2014, an international standard governing asset management in general. While only required when pursuing ISO certification, considering its guidelines can go a long way in keeping machinery working.
No matter how intricate industrial machinery grows, it will still consist of many single points of failure, at least for the short and medium term.
Control valves are proof of that, being essential to everything from manufacturing to public utilities. Their integrity and reliability must be ensured annually to prevent their problems from grinding systems to a halt.