In the industrial field, valves, as indispensable key components of industrial systems, are often referred to as the “joints” of these systems, playing a crucial role. Whether in chemical, power, petroleum, or metallurgical industries, industrial valves bear the heavy responsibility of controlling fluid flow, ensuring the stability and safety of production processes.
However, once a valve malfunctions and fails prematurely, it will bring a series of hidden losses. Valve failure may lead to fluid leakage, not only causing material waste and increasing production costs, but also potentially polluting the environment and even causing safety accidents. The lifespan of valves is directly related to the stability, safety, and economy of industrial production; how to extend valve lifespan has become a critical issue that urgently needs to be addressed in the industrial field.
Valve selection is like prescribing a precise remedy for different ailments; it must be comprehensively considered based on factors such as media characteristics, pressure, and temperature parameters. Examples include highly corrosive media and high-temperature, high-pressure steam pipeline systems.
Every detail in valve installation is crucial to the normal operation and service life of the valve.
Flange alignment is a key step in ensuring valve installation quality. If the flanges are not aligned, the valve will be subjected to uneven stress during operation. This uneven stress will cause the valve’s sealing surface to gradually wear down, eventually leading to poor sealing and leakage. Therefore, during installation, professional tools and measuring equipment must be used to ensure that the center axes of the two flanges are completely aligned, with the deviation controlled within a very small range, generally not exceeding ±0.5mm. Precise torque control is also crucial. Excessive torque may damage the valve’s connecting parts, such as breaking bolts; while insufficient torque will not guarantee a tight connection, also leading to leakage. It should also be noted that different valve specifications and materials require different torque requirements for connecting bolts; bolts with appropriate torque must be selected. Matching gaskets is also an essential step. The function of gaskets is to fill the gap between flanges and prevent media leakage. Different valves and piping systems require gaskets of appropriate specifications and materials. Pipeline cleanliness is equally important. Before installing valves, the pipeline must be thoroughly cleaned. High-pressure water flushing, chemical cleaning, and other methods can be used to remove impurities, welding slag, etc., from the pipeline. After cleaning, the pipeline should be inspected to ensure there are no residual impurities before valve installation.
As a key component in an industrial system, the performance of valves is closely related to the overall system operation. System problems such as pump inefficiency can cause additional losses to valves. Unstable pump flow can also cause valve impact, increasing the risk of valve damage. Therefore, when selecting valves, the appropriate diameter and type should be chosen based on pump flow, pressure, and other parameters to ensure stable valve operation in the system and reduce additional losses caused by system problems.
| Key Installation Indicators | Traditional Operation Standard | Optimized Operation Standard | Change in Failure Rate | Contribution to Valve Life |
| Flange Alignment Deviation | ＞0.5mm | ≤0.2mm | 30%→5% | +15% |
| Torque Control Error | ±15% | ±5% | 25%→3% | +12% |
| Gasket Compatibility | Universal Gaskets | Medium/Temperature-Specific Gaskets | 20%→2% | +10% |
| Pipeline Cleanliness | ＞50μm | ≤10μm | 18%→1% | +8% |
| Valve Selection Matching Degree | 60%-70% | ≥95% | 40%→8% | +20% |
Different types of valves have different testing cycles due to differences in their structure, working principle, and operating environment. For general-purpose valves, such as gate valves and globe valves, a basic test every 12 months is appropriate under normal operating conditions. For valves used in special environments, such as those in high-temperature, high-pressure, or highly corrosive environments, a comprehensive test is required every 6 months. Some critical valves, such as the main steam isolation valves in nuclear power plants, are essential for the safe operation of the system and typically require a deep overhaul every 3-5 years.
Seals are crucial components for maintaining valve tightness, therefore monitoring their condition is essential. Various methods can be used to monitor seal condition, such as visual inspection, measuring seal dimensions, and using leak detection instruments. Using manufacturer-certified lubricants for professional lubrication of moving parts is also an important measure to extend valve life. Different types of valves have different lubrication requirements for their moving parts. During lubrication, the manufacturer’s specified methods and dosages must be followed to ensure that the lubricant is evenly distributed on the surface of the moving parts for good lubrication.
ValvKeep and other valve management systems allow for comprehensive and accurate tracking and analysis of valve maintenance data. These systems can record basic valve information, such as model, specifications, and installation location; maintenance records, including the time, content, and replaced parts of each maintenance; and operational data, such as the number of valve openings, pressure, and temperature. Analysis of this data provides a clear understanding of the valve’s operating status and performance trends. It also generates maintenance reports and early warning information, offering decision support to managers and helping them better manage and maintain valves.
In corrosive and high-temperature environments, the use of hard alloy coatings, HVOF thermal spraying, and other protective technologies can effectively improve the valve’s corrosion resistance and high-temperature performance.
Equipping the valve with a corresponding micron-level filter, as required by the manufacturer, is a crucial measure for removing impurities and protecting the valve. Different valves and media have different requirements for filter precision. When selecting a filter, the appropriate filter type, precision, and filtration area should be chosen based on the manufacturer’s recommendations and actual operating conditions to ensure the filter functions effectively and protects the valve from damage by impurities. Regular cleaning and replacement of the filter are also necessary to maintain its filtration efficiency.
Selecting suitable sealing materials and valve construction is key to ensuring normal valve operation in different temperature ranges. In high-temperature environments, sealing materials need to have good high-temperature resistance to prevent aging, deformation, and loss of sealing performance at high temperatures. In low-temperature environments, sealing materials need to possess good low-temperature toughness to prevent the seals from hardening and cracking at low temperatures.
| Protection Method | Applicable Working Condition | Corrosion Resistance Level | Temperature Resistance Range | Wear Resistance | Contribution to Life Extension | Cost Increase Ratio |
| Ordinary Material (No Protection) | Neutral medium, normal temperature (20℃~80℃) | Level 1 (Weak Corrosion Resistance) | -20℃~120℃ | Level 1 | – | – |
| PTFE-lined Valve | Medium-low concentration corrosive medium (acid/alkali ≤30%), normal temperature | Level 3 (Medium Corrosion Resistance) | -40℃~150℃ | Level 2 | 30%-35% | 20%-30% |
| WC-Co Hard Alloy Coating | Medium-high concentration corrosive medium (acid/alkali ≤50%), medium temperature | Level 4 (Strong Corrosion Resistance) | -20℃~300℃ | Level 4 | 40%-45% | 40%-50% |
| HVOF Thermal Spraying (Cr₂O₃/WC) | High-temperature corrosive environment (acid/alkali ≤80%), high temperature | Level 5 (Extreme Corrosion Resistance) | -40℃~600℃ | Level 5 | 50%-55% | 60%-80% |
| 20-50μm Filter | Solid particle medium (particle size ＞20μm) | – | Matching valve temperature range | Level 3 | +15% | 5%-10% |
| 5-10μm Precision Filter | Suspended impurity medium (particle size ＞5μm) | – | Matching valve temperature range | Level 4 | +20% | 10%-15% |
| Low-temperature Special Seal Material | -40℃~-20℃ low-temperature scenarios | Matching medium corrosion level | -40℃~80℃ | Level 2 | +10% | 15%-20% |
| High-temperature Metal/Ceramic Seal | 300℃~600℃ high-temperature scenarios | Matching medium corrosion level | 300℃~600℃ | Level 5 | +25% | 30%-40% |
Strictly operating valves according to rated parameters is a fundamental requirement for ensuring normal valve operation and extending their service life. Overpressure, overtemperature, and excessive throttling can cause serious damage to valves. Overpressure operation will subject the valve to excessive pressure, leading to damage to valve seals, valve cores, and other components. Overtemperature operation will degrade the valve’s material properties, resulting in poor sealing performance and even valve body deformation. Excessive throttling will subject the valve core and seat to severe erosion and wear. Operators must strictly adhere to the valve’s rated parameters to ensure safe and stable operation.
Performing functional tests on valves that have been idle for a long time is an effective way to prevent valve jamming. Valves that have been idle for a long time are prone to jamming because the valve core, valve stem, and other components are in a static state for extended periods, making them susceptible to adhesion to seals or valve seats, preventing normal opening and closing. Regular “valve activation” is generally performed every 3-6 months. During “valve activation,” it is crucial to adhere to operating procedures to avoid damage to the valve due to improper operation.
Analyzing and controlling the cycle frequency based on valve type is an important measure to reduce frictional heat loss. Different types of valves have different optimal operating cycles and cycle frequencies. Therefore, it is necessary to operate according to rated parameters, avoid overpressure/excessive throttling, and perform regular functional tests on idle valves to optimize the cycle frequency and reduce friction.
On-site machining technology eliminates the need for disassembly to repair damaged sealing surfaces, offering advantages such as high efficiency, convenience, and economy. Traditional repair methods typically require removing the valve from the pipeline and transporting it to a repair shop, a process that consumes significant time and manpower and may cause secondary damage to the valve and pipeline. On-site machining technology allows for direct repair at the valve installation site, greatly shortening repair time and reducing production interruption losses.
Targeted replacement of corrosion-resistant seals and enhancement of valve stem and bearing wear resistance can effectively improve valve performance and service life. In highly corrosive environments, ordinary seals are easily corroded, leading to valve leakage. Therefore, it is necessary to replace them with corrosion-resistant seals, such as polytetrafluoroethylene (PTFE) seals and rubber-coated metal seals.
Valve stems move frequently during valve opening and closing, making them prone to wear. To improve the wear resistance of valve stems, surface hardening treatments such as chrome plating and nitriding can be used.
In the long run, implementing valve life management has significant economic and safety benefits. By extending valve life, the frequency of valve replacement is reduced, thereby lowering overall costs. This includes not only the purchase cost of new valves but also the installation and commissioning costs incurred due to valve replacement, as well as indirect losses caused by production interruptions. It can be said that valve life management is of paramount importance to the economic benefits and production safety of enterprises. Let us work together to extend valve life, reduce costs, and improve production efficiency and safety through scientific management and technological means, thus contributing to the sustainable development of industry.
