It is necessary to understand the safety issues related to gas storage tanks

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In the entire compressed air system, the compressed air storage tank is one of the most commonly used devices. It has a simple structure, and it helps to stabilize the pressure in the piping system, remove certain pollutants, reduce the frequent starting and stopping of compressors, extend the compressor’s lifespan, and lower energy consumption; it is an essential component of compressed air systems. However, in recent years, there have been frequent reports of accidents and even explosions in gas storage tanks, which severely disrupt production and cause significant damage to lives and property. Today, we will briefly analyze the reasons for such problems and the preventive measures. Why do gas storage tanks pose safety hazards? 1. Design flaw: The gas storage tank was not designed in accordance with the latest GB150 \"Pressure Vessels\" standards and related regulatory requirements. Unreasonable aspects such as the material of the equipment, design pressure, design temperature, welding factor, strength testing, non-destructive testing, the connection and reinforcement of fittings, the selection and determination of corrosion margins, as well as the installation of overpressure relief devices and the design structure, can all be factors that lead to safety risks for storage tanks. 02 Material defects in gas storage tanks and non-compliance with manufacturing standards: The materials used for gas storage tanks are of poor quality; the manufacturing process is inadequate, with no strength tests or non-destructive inspections carried out. Defects such as uneven wall thickness, pores, cracks, and severe rusting exist in certain areas. Even if the tank can operate at its rated pressure, its local strength is insufficient, which poses safety risks during system operation and may lead to accidents. Overpressure is one of the factors that can cause damage to gas storage tanks, and many factors can lead to overpressure. Issues such as an inappropriate selection of the gas storage tank – where the design pressure of the tank is lower than the exhaust pressure of the compressor – failure of the compressor’s built-in safety relief devices or pressure regulation mechanisms, failure of the tank’s safety valve, exposure of the tank to direct sunlight for extended periods, or placement of the tank in areas near sources of fire, can all lead to a risk of overpressure in the gas storage tank. 04 Combustion caused by oil accumulated over time: The vast majority of air compressors are oil-lubricated compressors, and the lubricating oil enters subsequent equipment and pipelines along with the compressed air. During long-term operation, due to the impure air, impurities present in it, metal rust, and degraded or emulsified oils, oily deposits gradually form along the entire exhaust passage. As gas storage tanks with buffering functions, due to the reduced flow velocity, these deposits can easily accumulate within the tank; under certain conditions (such as static electricity), this may lead to combustion, resulting in overpressure in the system and subsequent accidents. 05 Combustion caused by oil leakage from screw compressors. Faults in the oil-gas separation mechanism of screw air compressors, improper pipeline design, or operation of the compressor at pressures far below its rated level can result in an excessively high flow rate of gas passing through the oil-gas separation filter. This leads to a large amount of oil mist being carried into the storage tanks and pipeline systems downstream; this phenomenon is commonly referred to as oil leakage. At this point, the compressed air contains a large amount of lubricating oil; moreover, its high flow rate leads to an increase in static electricity as well. These two factors together significantly raise the likelihood of accidents. Once static electricity is not effectively discharged and the concentration of oil and gas reaches the explosive limit, the energy generated by an instantaneous discharge is sufficient to cause the oil and gas in the system to burn rapidly, leading to an accident. 06 Vibration: A significant issue in this regard is the vibration of a certain frequency that occurs during the suction and discharge process in piston air compressors; this vibration is transmitted through the pipelines. Improper installation of air storage tanks, as well as the lack of effective measures to eliminate vibrations in the pipes, can all result in additional fatigue loads being applied to the piping system. This can lead to loosening and cracking, which may cause leaks in mild cases, or even accidents in severe cases. 07 Improper maintenance and management: After reviewing reports and case studies of accidents involving compressed air storage tanks, it is evident that improper management and maintenance play a significant role in such accidents. Operators and managers lack safety awareness, equipment is not under proper management, safety accessories are not regularly calibrated, contaminants in storage tanks are not cleaned on a regular basis, and equipment continues to be used beyond its designed lifespan, among other issues. Measures to prevent accidents in air storage tanks. Choose qualified products. For the vast majority of ordinary users, they lack the expertise to determine whether the design drawings of compressed air storage tanks comply with standards, whether the materials used are of appropriate quality, and whether the manufacturing process follows the required specifications. Users should choose products manufactured by professional pressure vessel manufacturers. It is important to verify whether such manufacturers possess the necessary design and manufacturing qualifications, as well as whether they have obtained relevant certifications for their quality management systems. By using appropriate business information lookup tools, it is possible to find out if the manufacturers have been subject to any administrative penalties related to product quality or if there are any related lawsuits. Avoiding the temptation to save money and opting instead for products from manufacturers that prioritize quality and reputation can help to effectively prevent risks associated with the design and manufacture of storage tanks. Select the appropriate product: Choose a storage tank that is compatible with the exhaust pressure of the air compressor in order to meet the requirements of the production process. The design pressure of the storage tank should be at least equal to the maximum exhaust pressure that the air compressor can achieve, and effective safety relief devices should be installed in accordance with relevant standards to ensure safety in case of overpressure. To prevent overpressure, in addition to having a properly installed, reliable, and effective safety relief device on the air storage tank itself, the air compressor must also have effective protection measures that stop the increase in pressure when it reaches the rated value. The compressor itself should be equipped with a qualified and effective safety relief device as well. If pressure regulation devices are installed in the pipelines leading to the air storage tank, it is necessary to ensure their reliability, along with the effectiveness of the overpressure protection devices, so as to prevent any risks associated with overpressure in the system. Control of pollutants in the storage tank and elimination of static electricity: The gas storage tank holds compressed air, which contains sufficient oxygen; therefore, during operation of the system, combustion can occur as long as two necessary conditions are met: the presence of combustible materials and a source of ignition. Since combustion releases a large amount of heat in a short period of time, causing the compressed air in the system to expand rapidly, the safety relief devices in the air storage tanks often cannot withstand such excessive loads, which can easily lead to accidents. We can reduce system risks by controlling two factors: the amount of combustible material and the ignition source; we should select compressors of reliable quality and use them under their rated operating conditions ； The compressor requires strict control over the amount of lubricating oil added ； When it is detected that the lubricant level in the compressor is decreasing rapidly, or when a large amount of oil contamination is discharged from the system, the machine should be stopped immediately for inspection ； Use a compressed air tank equipped with maintenance access holes, and regularly clean the deposits on its inner wall ； Control the exhaust temperature of compressed air ； Since the static electricity generated by friction as gas flows must be discharged in a timely manner to prevent excessive accumulation of static electricity from causing sparks, the piping systems and storage tanks need to be reliably grounded in accordance with design requirements, in order to eliminate the impact of static electricity on the system. Proper installation of storage tanks and pipelines and elimination of vibrations: Storage tanks and pipelines must be installed and secured in a reliable manner in strict accordance with design requirements, and they should be placed in a cool location away from sources of fire. Fixed supports and hangers should be installed on the pipe near the equipment nozzles to reduce the gravitational stress on those nozzles. When designing pipes, bends, branch pipes, and reducers should be minimized as much as possible to reduce excitation forces. For pipes that are already vibrating, pipe supports and clamps can be added at the source of vibration and at the points where the amplitude is highest ； At bends and tees, pipe clamps are used for distributed fixation in multiple locations to reduce the additional stress on the pipes ； In the case of vibrations caused by pulsed flows such as those from pistons, buffers can be added, and orifice plates can be installed near the flanges of the container to reduce the impact of vibrations on the equipment nozzles and other components. Strengthen the maintenance and management of equipment, raise the safety awareness of operators, assign dedicated personnel to manage the equipment, regularly inspect safety accessories such as gas storage tanks, and replace those that are damaged or no longer functional promptly to ensure that the equipment operates without defects ； Regularly remove pollutants ； Operate and record strictly in accordance with the regulations. It can **reduce the incidence of accidents**. Compressed air storage tanks are often overlooked due to their simple structure, and the safety risks they pose are not taken into account. However, as one of the most commonly used devices in compressed air systems, their safe operation is of great importance for such systems. To ensure the safe, long-lasting, and stable operation of gas storage tanks, it is first necessary to analyze in detail the various potential risk factors discussed in this article. Strict controls must be implemented in aspects such as the design and materials of the tanks, as well as their installation and operational safety management, in order to completely eliminate potential hazards and guarantee the safe operation of the tanks, thereby enhancing the safety and stability of the compressed air system.