Shandong Zhongjie Special Equipment (formerly Heze Boiler Factory Co., Ltd.) holds an A-grade boiler manufacturing license, an A2-grade pressure vessel manufacturing license, an A2-grade pressure vessel design license, a B-grade boiler installation license, and GB2/Class, GC2/Class pressure pipeline installation licenses, as well as a mechanical and electrical equipment installation contracting qualification. It is a member of the China Boiler and Water Treatment Association, the China Chemical Equipment Association, and the Council Member of the Shandong Equipment Manufacturing Association. The company has also passed certifications for the ISO9001 Quality Management System, ISO14001 Environmental Management System, OHSAS18001 Occupational Health and Safety Management System, and the American ASME/U2 certification.
The primary reason for pre-cooling a liquid oxygen tank before use is to lower the tank's internal temperature to below the boiling point of liquid oxygen, facilitating the conversion of oxygen into a liquid state.
The boiling point of liquid oxygen is -183°C, and at room temperature, oxygen exists in a gaseous state. Liquid oxygen tanks require cooling the oxygen below its boiling point to convert it into a liquid for storage and supply.
The pre-cooling process typically includes the following steps:
Clean Storage Tanks: First, the tank must be thoroughly cleaned to ensure no impurities or contaminants are present inside, to avoid affecting liquid oxygen.
Drainage and Exhaust: Empty the gas from the storage tank and expel it through the exhaust system to reduce the gas content within the tank.
Add Liquid Nitrogen: Inject liquid nitrogen into the tank, which can rapidly cool the air and walls inside the tank due to its low temperature, thereby reducing the tank's temperature.
Wait for cooling: The liquid nitrogen in the tank will gradually lower the temperature inside the tank through the heat conduction process until it reaches below the boiling point of liquid oxygen.
The purpose of pre-cooling is to ensure that the temperature inside the storage tank is low enough to meet the storage and supply requirements of liquid oxygen. Pre-cooling can reduce the evaporation and loss of liquid oxygen, while also helping to maintain the safety and stability of the tank.

The testing and maintenance operations for liquid oxygen storage tanks encompass the following aspects:
Visual Inspection: Regularly inspect the liquid oxygen storage tank for any signs of corrosion, wear, leakage, and other issues on the tank surface to ensure its appearance remains intact.
Pressure Testing: Regularly conduct pressure tests on liquid oxygen tanks to assess their pressure resistance. The tests should be carried out in accordance with relevant standards and regulations to ensure the tank can withstand the designed working pressure.
Leak Detection: Regularly conduct leak detection on liquid oxygen storage tanks, including using leak detection equipment to inspect the tanks to ensure their sealing performance is good and there are no leak issues.
Cleaning and Coating Protection: Regularly clean and apply protective coatings to liquid oxygen tanks to prevent corrosion and oxidation. Use appropriate cleaning agents during cleaning and avoid substances that react with liquid oxygen. Protective coatings can be applied using anti-corrosion coatings or protective agents.
Regular Maintenance: Conduct regular maintenance on liquid oxygen tanks, which includes inspecting and replacing seals, valves, safety devices, etc., to ensure proper operation and safety.
Safety Training and Operating Procedures: Conduct safety training for personnel using liquid oxygen tanks to ensure they are aware of the safe operating procedures and precautions, to avoid operational errors and accidents.
Record and Document Management: Establish testing and maintenance records for liquid oxygen storage tanks, including test results, maintenance logs, and inspection records, for traceability and management purposes.
It's important to note that the testing and maintenance of liquid oxygen tanks should be conducted by trained personnel, adhering to relevant safety operating procedures and standards. Additionally, a specific testing and maintenance plan should be established based on the tank's condition and usage requirements, and executed according to the plan.

When selecting the support for a liquid argon storage tank, consider the following factors:
Load Capacity: The support must be capable of bearing the weight of the liquid argon tank. Select a support with adequate load capacity based on the tank's capacity and dimensions. Typically, the weight of the liquid argon tank is specified in the design specifications, which can be used to determine the support's load capacity.
Stability: The support must provide sufficient stability to prevent the tank from tilting or swaying during operation. The design of the support should take into account the tank's center of gravity and its changes to ensure stable support.
Corrosion Resistance: Liquid argon has low temperature and corrosive properties; the support material should possess good corrosion resistance to prevent corrosion and damage. Common support materials include stainless steel, aluminum alloy, etc.
Insulation: Liquid argon storage tanks typically require thermal insulation. The supports should have certain insulation properties to reduce heat transfer and the evaporation of liquid argon. The design of the supports should take into account the installation and protection of the insulation layer.
Installation and Maintenance: The support should feature ease of installation and maintenance for convenient tank installation and routine maintenance tasks.
When selecting the supports for liquid argon tanks, it's advisable to consult with engineers or suppliers. Choose the appropriate supports based on the specific tank requirements and operating environment. Also, adhere to relevant design specifications and safety standards to ensure the quality and reliability of the supports.

The filling of a low-temperature liquid nitrogen tank refers to the process of transferring liquid nitrogen from an external supply source into the tank. Below is an explanation of the filling process for low-temperature liquid nitrogen tanks:
Preparation: Prior to filling the liquid nitrogen tank, thorough preparation is required. This includes inspecting the tank's condition and safety to ensure it is clean, free of impurities and contaminants. Additionally, check the quality of the liquid nitrogen from the supply source and the safety of the supply pipeline.
Connect supply source: Link the liquid nitrogen supply source to the liquid inlet of the storage tank. Ensure the connection is securely fastened to prevent leaks.
Control the liquid level: During the bottling process, it is necessary to control the level of liquid nitrogen to prevent overfilling or overflow. A level gauge or level control system can be used to monitor and control the liquid level.
Slow Injection: The injection of liquid nitrogen should be done slowly to prevent rapid vaporization and increased pressure. Appropriate valves and flow control devices can be used to regulate the injection rate.
Monitor Pressure: During the canning process, it is necessary to monitor the tank's pressure to ensure it remains within a safe range. Pressure gauges or pressure sensors and similar equipment can be used for monitoring.
Canning completed: Stop the injection of liquid nitrogen when the liquid level reaches the predetermined filling amount or the tank's capacity limit. Disconnect the connection with the supply source and ensure the sealing of the filling port.
Safety Operation: Throughout the canning process, it is necessary to follow relevant safety regulations and operation guidelines. Liquid nitrogen is characterized by low temperature and high flammability; operators must wear appropriate personal protective equipment and ensure the operation environment is free of any ignition sources.
When bottling liquid nitrogen, be mindful of its low-temperature properties and safety. Ensure safe operation and control throughout the bottling process to guarantee the safe operation of the storage tank and the effective storage of liquid nitrogen.
Our company attaches great importance to technological innovation and research and development. We have one municipal-level enterprise technology center in Heze City, equipped with testing facilities for non-destructive testing, physical and chemical testing, welding testing, hydrostatic testing, etc. We have over 600 types of equipment, including CNC machine tools, X-ray flaw detectors, digital ultrasonic flaw detectors, mechanical property testing machines, chemical analyzers, spectrometers, tensile testing machines, plasma welding machines, and more. The key products and technologies we have developed, such as welding for temperature and pressure vessels, biomass boiler emission reduction, and waste heat utilization, have successively been included in multiple Shandong Provincial Department of Industry and Information Technology scientific and technological innovation projects, key projects of Shandong Province, and Heze City innovative and excellent projects. We have accumulated 27 authorized utility model patents, 16 authorized invention patents, participated in drafting 2 standards, 2 industry standards, and registered 15 trademarks. The technical team of our company, in collaboration with Professor Li Yajiang of Shandong University, has developed deep cryogenic container processing technology using the international plasma arc + wire filling argon arc welding (PAW-GTAW) technology. The provincial-level scientific and technological achievement identification has confirmed that the technology level in the field of deep cryogenic container manufacturing has reached an international standard. Choose Zhongjie Special Equipment, and let's create brilliance together!