Valve Maintenance: How to extend valve life
2024-12-25
Valve Maintenance: How to extend valve life
Valve Maintenance: How to extend valve life
Valves play a vital role in the efficiency and safety of industrial systems, controlling the flow of liquids, gases and mud. Whether in water treatment plants, oil and gas pipelines, or manufacturing facilities, valves are subject to varying degrees of pressure, temperature, and corrosion. Therefore, for the smooth operation of the system, proper valve maintenance is very important: it can reduce downtime, increase life expectancy and reduce long-term operating costs. In some applications, poorly maintained valves can lead to potentially unsafe environments where high pressures can build up or harmful and dangerous liquids can be released. In this article, we'll explore some basic valve maintenance tips and best practices to help you extend the life of your valves, avoid premature failure, and maximize your return on investment.
Select the right valve type
Sometimes, more than one type of valve can perform a certain function in a process, but often, only one type is best suited. In industrial process heating, valves are also needed to control the heat load, temperature and pressure in steam applications. The correct selection of valves requires knowledge of application functions, operating conditions (temperature and pressure) and safety requirements. The type of liquid is also important.
After selecting the valve, it must be properly sized according to the pipe size and fluid conditions. Small valves in large flow processes will experience high flow rates, which may wear down the internal valve components. This can lead to leaks and loss of control. Fluid type also affects valve type and material. Compatibility charts help determine which valve materials are chemically resistant to process fluids.
If the valve is operated remotely, the actuator size must also be appropriate and the torque correct. Usually, in order to avoid overheating of undersized actuators, it is easy to make the actuator too large, but too large actuators can cause the valve stem to twist.
Operating within thermal limits
Arguably, the most important consideration for valve life expectancy is the time the valve operates inside and outside the thermal limit.
The thermal limit is defined by the maximum operating conditions of temperature and pressure. Each valve is designed to operate under specific conditions determined and specified by the manufacturer. Restrictions are based on the material type selected for body, seals/seats, stem, gland packing, closing mechanism, etc. Special valves are available - designed for higher than usual thermal limits.
Short time operation of most valves exceeding specified limits will not immediately affect the performance of the valve. It might be tempting to think that the valve is suitable for such cases. However, continuous operation of the valve beyond this limit will slowly damage it, thereby significantly shortening the life expectancy.
A typical example is operating a valve above the specified 176°F (80°C) design limit. While a valve with a stainless steel body may be durable under such conditions, a valve seal that is invisible and made of polymer is not. Each time it is exposed to temperatures above 176°F, the seals slowly expand and deform, eventually leading to valve leakage
Regular inspection and monitoring
Regular inspections are essential to detect early signs of wear, corrosion and potential failures. By monitoring valves regularly, you can spot problems before they escalate into costly repairs or operational downtime. During the inspection, please check:
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Leaks: Even minor leaks can indicate an underlying problem, such as seal damage or corrosion.
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Abnormal sound or vibration: A change in sound or an increase in vibration may indicate a loose part or an internal blockage.
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Visual damage: Look for signs of external wear, corrosion, or physical damage.
Scheduling regular inspections as part of routine maintenance helps identify problems early and plan proactive measures.
Ensure proper lubrication
Lubrication is essential for maintaining valve function, especially for moving parts such as stems, gears and bearings. Proper lubrication reduces friction, prevents corrosion, and seals to protect against contaminants. However, it is crucial to use the correct type of lubricant as recommended by the valve manufacturer, as different materials and operating conditions require specific lubrication properties.
