Shandong Zhongjie Special Equipment (formerly Heze Boiler Factory Co., Ltd.) holds an A-grade boiler manufacturing license and an A2-grade pressure vessel manufacturing license, an A2-grade pressure vessel design license, a B-grade boiler installation license, and GB2/GC2 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 a director unit of the Shandong Equipment Manufacturing Association. The company has also passed the ISO9001 Quality Management System, ISO14001 Environmental Management System, OHSAS18001 Occupational Health and Safety Management System certifications, 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. To store and supply it, the liquid oxygen tank must cool the oxygen below its boiling point to transform it into a liquid form.
The pre-cooling process typically involves the following steps:
Clean Storage Tank: First, the tank must be thoroughly cleaned to ensure there are no impurities or contaminants 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 inside the tank.
Add Liquid Nitrogen: Injecting liquid nitrogen into the tank will rapidly cool the air and walls inside the tank with its low temperature, thereby reducing the tank's temperature.
Wait for Cooling: The liquid nitrogen inside the tank will gradually lower the temperature of the tank through the process of heat conduction until it falls 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 for liquid oxygen. Pre-cooling can reduce the evaporation and loss of liquid oxygen, and also helps 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 tank for any signs of corrosion, wear, or leakage on the surface, ensuring the tank's exterior remains intact.
Pressure Testing: Regularly conduct pressure tests on liquid oxygen tanks to assess their pressure resistance. The tests should be conducted in accordance with relevant standards and specifications to ensure the tank can withstand the designed working pressure.
Leak Detection: Regularly conduct leak detection on liquid oxygen tanks, including using leak detection equipment to inspect the tanks to ensure their sealing performance is good and there are no leakage issues.
Cleaning and Coating Protection: Regularly clean and coat the liquid oxygen storage tank to prevent corrosion and oxidation. Use appropriate cleaning agents during cleaning and avoid substances that react with liquid oxygen. Coating protection can be achieved through anti-corrosion coatings or protective coatings.
Routine Maintenance: Regularly maintain liquid oxygen tanks, including inspections and replacement of 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 familiar with the safe operating procedures and precautions, in order to prevent operational errors and accidents.
Documentation and Record Management: Establish test and maintenance records for liquid oxygen storage tanks, including test results, maintenance logs, and inspection records, for traceability and management purposes.
It's important that testing and maintenance of liquid oxygen tanks be conducted by trained personnel and in accordance with relevant safety operating procedures and standards. Additionally, a specific testing and maintenance plan should be developed based on the tank's conditions and usage requirements, and executed as scheduled.

When selecting the pedestal for a liquid argon tank, several factors should be considered:
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 load capacity of the support.
Stability: The support must provide sufficient stability to prevent the tank from tilting or swaying during use. The design of the support should consider 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 have excellent corrosion resistance to prevent corrosion and damage. Common support materials include stainless steel, aluminum alloy, etc.
Insulation: Liquid argon storage tanks generally require thermal insulation. The supports should have certain insulation properties to reduce heat transfer and evaporation of liquid argon. The design of the supports should consider the installation and protection of the insulation layer.
Installation and Maintenance: The support should be designed for ease of installation and maintenance, facilitating the tank's setup and routine upkeep.
When selecting the support for a liquid argon tank, it's advisable to consult with engineers or suppliers. Choose the appropriate support based on the specific tank requirements and usage environment. At the same time, adhere to relevant design specifications and safety standards to ensure the quality and reliability of the support.

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: Before filling the liquid nitrogen tank, thorough preparation is required. This includes inspecting the tank's condition and safety, ensuring the interior 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 tight and secure to prevent leaks.
Control Liquid Level: During the bottling process, it is necessary to control the liquid nitrogen level to prevent overfilling or overflow. A liquid level gauge or a liquid level control system can be used to monitor and control the 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 Completion: Cease nitrogen gas injection once the liquid nitrogen level reaches the predetermined filling quantity or the tank's capacity limit. Disconnect from the supply source and ensure the sealing integrity of the filling port.
Safety Operation: Throughout the canning process, relevant safety regulations and operational guidelines must be followed. Liquid nitrogen is highly flammable and has low temperatures, so operators should wear appropriate personal protective equipment and ensure the operating environment is free of any ignition sources.
When bottling liquid nitrogen, be mindful of its low-temperature characteristics and safety. Ensure safe operation and control during 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 R&D, boasting one municipal-level enterprise technology center in Heze City. We have established testing facilities for non-destructive testing, physical and chemical testing, welding testing, hydrostatic testing, and more, equipped with over 600 various instruments and equipment such as CNC machine tools, X-ray flaw detectors, digital ultrasonic flaw detectors, mechanical property testing machines, chemical analyzers, spectrometers, tensile testing machines, and plasma welding machines. The key products we have developed, such as welding technology for temperature-pressure vessels, biomass boiler emission reduction, and waste heat utilization, have successively been included in multiple Shandong Provincial Department of Industry and Information Technology science and technology projects, Shandong Provincial key projects, and Heze City innovation and excellence projects. We have cumulatively obtained 27 authorized utility model patents, 16 authorized invention patents, participated in drafting 2 standards, 2 industry standards, and registered 15 trademarks. Our technical team, in collaboration with Professor Yajiang Li of Shandong University, has developed deep cryogenic container processing technology using the international plasma arc + filler wire argon arc welding (PAW-GTAW) technique. This technology has been appraised as reaching international standards in the field of deep cryogenic container manufacturing. Choose Zhongjietech, let's create brilliance together!