Storage Tanks Installation and Maintenance

In industrial production, storage tanks play a crucial role as key equipment for storing and transporting various liquids. Whether it's food, pharmaceuticals, or chemical raw materials, the safety and reliability of storage tanks directly impact the safety and efficiency of production processes. Therefore, understanding the installation procedures and the importance of regular inspections is essential for ensuring production safety and the long-term stable operation of the equipment. This article will provide a detailed introduction to the installation requirements, maintenance and inspection procedures, and relevant precautions for storage tanks, aiming to offer a practical guide for relevant staff.

Storage Tank Installation Operation Procedures

The installation phase is critical for ensuring the safe operation and long-term stable use of storage tanks. Proper installation not only prevents equipment damage caused by improper installation but also facilitates subsequent maintenance and inspection. Below are the detailed installation procedures for storage tanks.

1. Foundation Settlement Test

Before installing a storage tank, a settlement test must be conducted on the tank foundation. This test ensures the stability of the foundation and prevents the tank from shifting during operation. A stable foundation is a prerequisite for the safe operation of the storage tank. Only on a solid and stable foundation can the tank withstand various pressures and weights, avoiding safety accidents caused by uneven foundation settlement.

2. Layout of Vent and Drain Pipes

Vent pipes should be evenly and centrally arranged to ensure the smooth discharge of gases. The height of the drain pipe should not be less than 5 meters. This height setting prevents backflow of water into the storage tank. Additionally, a bend or rain cap should be installed at the upper end of the vent pipe. This not only prevents rainwater from entering the vent pipe directly but also prevents the accumulation of dust and debris, ensuring the unobstructed flow of the vent pipe.

3. Setting of Saddle Supports

If the tank is installed on two saddle supports, one support should be a fixed end and the other should be a movable end. This design allows the tank to expand and contract freely with temperature changes, avoiding stress damage to the tank caused by thermal expansion and contraction. At the same time, liquid pipelines should be installed near the fixed end. This reduces vibration and stress in the pipelines during operation, enhancing the stability of the system.

4. Tank Inclination and Sewage Discharge

The installation position of the tank should be inclined towards the liquid pipeline end, with a slope controlled between 0.01 and 0.02. This inclined design facilitates the flow of liquids and prevents accumulation within the tank. Additionally, a sewage discharge valve should be installed at an appropriate location on the tank to regularly discharge sewage, maintaining the cleanliness and hygiene inside the tank.

5. Setting of Sprinkler Control Valves

The control valves for sprinklers should be located away from the storage tank. This design consideration takes into account emergency situations such as fires. In the event of a fire when access to the tank area is impossible, the control valves located away from the tank ensure that personnel can promptly open the valves for water spraying to extinguish the fire, thereby minimizing the damage to the storage tank.

6. Special Requirements for Spherical Tanks

For spherical tanks supported by equatorial columns, it is essential to ensure that the columns do not move relatively in the vertical and horizontal directions. Additionally, uniform settlement of the columns must be guaranteed to prevent deformation or damage to the tank caused by uneven settlement. These requirements are crucial for the long-term stable operation of spherical tanks.

Regular Inspection of Storage Tanks

Regular inspection is a vital component in ensuring the safe operation of storage tanks. Through regular inspections, potential issues that may arise during the use of the tank can be identified promptly, and appropriate measures can be taken for repair and improvement, thereby ensuring the stability and safety of the storage tank.

1. Types and Frequency of Inspections

Regular inspections of storage tanks are divided into external inspection, internal and external inspection, and comprehensive inspection. The frequency of inspection should be determined based on the technical condition of the equipment and the conditions of use. Generally, external inspection should be conducted at least once a year, internal and external inspection at least once every three years, and comprehensive inspection at least once every six years. For tanks that have been in use for 15 years, internal and external inspections should be carried out every two years; for tanks that have reached their service life, internal and external inspections should be conducted at least once a year. These inspection frequencies are set to promptly identify potential issues that may arise during the use of the tank, ensuring its safe operation.

2. Preparations Before Inspection

Before conducting an inspection, adequate preparations must be made. First, relevant technical documents should be reviewed to understand the defects found in the tank during manufacturing, installation, and use. These documents can help inspectors conduct targeted inspections, improving the efficiency and accuracy of the inspection. Secondly, anti-static grounding devices, fire separation layers, and exhaust ports should be installed within the coal pillars. These devices can effectively prevent fires and explosions caused by static electricity while ensuring good ventilation inside the storage tank. Additionally, the internal medium of the storage tank should be removed, and blind flanges should be used to isolate it from connected equipment and pipelines, with clear disconnection markings. For tanks that have undergone regular inspection, an inspector should submit an inspection report, stating whether the tank can continue to be used or if special monitoring measures are required. The inspection report should be properly stored in the tank's technical archives for future reference.

3. Cleaning and Purging of Tanks

Purging and cleaning of residual gases in the tank is an important step before inspection. Sampling and analysis should meet safety standards to ensure that the gas environment inside the tank is safe and reliable. All manholes of the storage tank should be opened, internal components removed, and dirt on the inner walls cleaned. Power related to the tank should be disconnected to prevent electric shock accidents during the inspection, ensuring the personal safety of the inspectors. The tank area should be equipped with fire-fighting, safety, and ambulance facilities to deal with potential emergencies. If fire-fighting operations are required, the necessary fire-starting approval procedures must be followed to ensure the legality and safety of the fire-fighting operations.

4. Safety Measures During Inspection

When entering the tank for inspection, low-voltage explosion-proof lights with a voltage not exceeding 12V or 24V should be used to prevent fires or explosions in flammable and explosive environments. A dedicated supervisor must be outside the tank to provide timely assistance in case of emergency. When the power supply voltage for inspection instruments and maintenance tools exceeds 36V, insulated and reliably grounded flexible cables must be used to prevent electric leakage accidents and ensure the safe conduct of the inspection.

Main Scope of Storage Tank Inspection

In the regular inspection of storage tanks, clarifying the main contents of the inspection is key to ensuring that the inspection work is comprehensive and efficient. These contents cover various aspects of the storage tank, including its external and internal structure, anti-corrosion layer, welds, safety accessories, and more.

1. External Inspection

The main contents of the external inspection include checking whether the anti-corrosion layer, insulation layer, and equipment nameplate of the storage tank are intact. The external surface of the tank should be examined for any abnormal phenomena such as cracks, deformation, or localized overheating, which may be external manifestations of internal problems. At the same time, the welds of the tank's pipelines and pressure-bearing components should be checked for any leaks, which is crucial for ensuring the tank's sealing performance. All items for internal and external inspection of safety accessories and control devices should be complete, sensitive, and reliable, as these accessories and devices play a vital role in the safe operation of the storage tank. Non-destructive testing should be conducted on the main welds or shell, with a sampling length of 20% of the total weld length or shell area of the container. This type of testing can promptly identify potential issues in the welds and shell, preventing the further escalation of problems.

2. Internal and External Inspection

When decarburization, stress corrosion, intergranular corrosion, or fatigue cracks are found on the inner wall of the storage tank, metallographic examination and surface hardness testing should be carried out, and an inspection report should be provided. These inspection items can provide a deeper understanding of the performance changes in the internal materials of the storage tank, offering a scientific basis for maintenance and repair. Internal and external inspection is an important part of a comprehensive assessment of the storage tank. Through these inspections, potential problems that may arise both inside and outside the tank can be identified promptly, and appropriate measures can be taken for repair and improvement, ensuring the safe operation of the storage tank.

3. Comprehensive Inspection

The main contents of the comprehensive inspection include checking whether the fastening bolts are in good condition and whether the foundation has any abnormal phenomena such as settlement or inclination. The condition of the fastening bolts directly affects the sealing and stability of the storage tank. Regularly checking the tightness and wear of the fastening bolts and promptly replacing damaged ones can effectively prevent tank leakage and deformation. Settlement and inclination of the foundation are important factors that affect the safe operation of the storage tank. Regularly checking the condition of the foundation can help identify and address foundation issues in a timely manner, ensuring the stability and reliability of the tank's foundation.

Conclusion

The installation and maintenance of storage tanks is a complex and important task that involves various technical and operational requirements. By strictly adhering to installation procedures, regularly conducting inspections and maintenance, the safe operation of storage tanks can be effectively ensured, and their service life can be extended. Understanding the characteristics and applications of stainless steel storage tanks, as well as the role and requirements of steam separators, is also significant for relevant staff to better manage and utilize these pieces of equipment. It is hoped that the introduction in this article will provide useful references and guidance for those engaged in the installation and maintenance of storage tanks, jointly promoting the safety and efficient development of industrial production.