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 and 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 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 application of strain-hardening in austenitic stainless steel on low-temperature pressure vessels is a common method, which can enhance the material's strength and durability. Below is some information regarding the application of strain-hardening in austenitic stainless steel on low-temperature pressure vessels:
Principle of Strain Hardening: Strain hardening is achieved by introducing plastic deformation into the material, altering the crystal structure and thereby increasing the material's strength. In Austenitic stainless steel, strain can be introduced through methods such as cold working (e.g., cold rolling, cold drawing) or heat treatment (e.g., solution treatment and cold deformation), which causes dislocations and grain boundary sliding in the crystal structure, thereby enhancing the material's strength.
Low-Temperature Application Advantages: Austenitic stainless steel exhibits excellent corrosion resistance and low-temperature toughness in cold environments. Strain hardening further enhances the strength and durability of austenitic stainless steel, enabling it to perform in low-temperature pressure vessels. Under low-temperature conditions, strain hardening effectively resists plastic deformation and fracture, improving the material's tensile strength and impact resistance.
Application Cases: Strain-hardened austenitic stainless steel is widely used in low-temperature pressure vessels. For instance, in liquid nitrogen, liquid oxygen, and liquid argon tanks, etc., strain-hardened austenitic stainless steel is commonly used as structural material. These vessels must withstand high pressure and impact loads at low temperatures; strain-hardening enhances the material's strength and durability, ensuring safe operation of the containers.
It should be noted that the strain hardening of austenitic stainless steel must be carried out at appropriate temperatures and deformation conditions to avoid excessive deformation and material embrittlement. When designing and manufacturing low-temperature pressure vessels, it is essential to select and apply austenitic stainless steel strain hardening reasonably, based on specific engineering requirements and material characteristics.

Low-temperature liquid oxygen storage tanks typically require certain safety accessories to ensure safe operation and to address potential risks. The following are some common safety accessories for low-temperature liquid oxygen storage tanks:
Pressure Sensor: Used to monitor pressure changes within storage tanks. If the pressure exceeds the set range, it will trigger an alarm or automatically stop filling measures to prevent overpressure in the tank.
Safety valve: Used to automatically release gas when the pressure inside the storage tank exceeds the set value, preventing overpressure. The safety valve should be selected and installed based on the design pressure and capacity of the storage tank.
Pressure Relief Device: Used to release gas into a safe area when the pressure inside the storage tank is too high, thereby reducing the pressure on the tank. The pressure relief device typically includes relief valves, relief pipes, etc.
Level sensor: Used to monitor the level change of liquid oxygen inside storage tanks to ensure an adequate supply and prevent overfilling.
Temperature Sensor: Used to monitor temperature changes within storage tanks to ensure that the temperature of liquid oxygen inside remains within a safe range.
Fire Detectors and Fire Suppression Systems: Designed to monitor fire risks around storage tanks and activate fire suppression systems as needed to prevent the spread of fire to other areas.

Nitrogen flushing in liquid nitrogen storage tanks refers to the process of injecting nitrogen gas into the tank to increase the nitrogen concentration and pressure inside, in order to meet certain safety requirements and operational objectives. Here are some precautions to consider when nitrogen flushing liquid nitrogen storage tanks:
Safe Operation: Prior to nitrogen charging operations on liquid nitrogen tanks, it is mandatory to ensure that the operators possess relevant safety knowledge and skills. Operators should wear appropriate personal protective equipment, such as safety goggles, gloves, and protective clothing.
Nitrogen Quality: Utilize high-purity nitrogen for inerting operations to ensure the quality and purity of the nitrogen. Low-purity nitrogen may contain impurities or oxygen, which could adversely affect the liquid nitrogen within the storage tank.
Nitrogen Flush Rate Control: During the nitrogen flushing process, the flush rate should be controlled to avoid being too fast or too slow. Too fast a flush rate can lead to excessive internal pressure within the tank, while too slow a flush rate can result in an extended flushing time.
Pressure Monitoring: During the nitrogen charging process, the internal pressure of the tank should be regularly monitored. Ensure the internal pressure of the tank remains within the safe range and adjust as necessary.
Temperature Control: During the nitrogen purge process, attention should be given to controlling the temperature of the storage tank. The low temperature of liquid nitrogen can lead to condensation and dew on the tank and pipelines. Appropriate measures, such as heating or insulation, should be taken to prevent condensation and dew from occurring.
Post-nitrogen flushing treatment: After the nitrogen flushing operation is completed, the flushing unit should be promptly shut off, and the tank should be inspected and cleaned. Ensure that there is no residual nitrogen or impurities inside the tank.
Note: Nitrogen purging operations for liquid nitrogen tanks must be strictly adhered to the relevant safety standards.

Zhongjie Special Equipment Co., Ltd. is a company engaged in the manufacturing of low-temperature liquid storage tanks. They offer a range of low-temperature liquid storage tanks in various specifications and capacities, including liquid nitrogen tanks, liquid oxygen tanks, liquid argon tanks, and more.
The Zhongjie低温 liquid storage tank is made with high-quality materials and advanced manufacturing techniques, ensuring the tank's strength and sealing integrity. The internal design incorporates special insulation materials and structural engineering, effectively reducing evaporation losses of the liquid.
The Zhongjie Specialized Low-Temperature Liquid Storage Tanks feature the following characteristics:
High safety: Tanks are made of materials with excellent pressure resistance and sealing performance, capable of safely storing low-temperature liquids.
Low evaporation loss: The insulating materials and structural design used inside the tank effectively reduce liquid evaporation loss, enhancing the tank's economic efficiency.
A variety of specifications and capacities available: Zhongjie offers a range of specifications and capacities for low-temperature liquid storage tanks to meet different customer needs.
Customized Design: According to the specific requirements of our clients, ZJET can offer customized design and manufacturing services to cater to various application scenarios.
Quantity Manufacturing Process: Zhongjie's state-of-the-art manufacturing equipment and technical team ensure the quality and performance of the storage tanks.
In summary, ZJET's custom-made low-temperature liquid storage tanks offer high safety, low evaporation loss, and a variety of specifications, making them suitable for storage and transportation needs for low-temperature liquids.
Our company attaches great importance to technological innovation and research and development design. We have 1 municipal-level enterprise technology center in Heze City, and have built testing facilities for non-destructive testing, physical and chemical testing, welding testing, hydrostatic testing, etc. We are equipped with 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, emission reduction in biomass boilers, and waste heat utilization, have successively been shortlisted for multiple Shandong Provincial Department of Industry and Information Technology science and technology innovation projects, Shandong Provincial key projects, and Heze City innovation and excellence projects. We have accumulated a total of 27 authorized utility models, 16 authorized inventions, participated in drafting 2 standards, 2 industry standards, and registered 15 trademarks. The technical team of our company, in collaboration with Professor Yajiang Li from Shandong University, has developed deep cryogenic container processing technology, which utilizes the internationally recognized plasma arc + filler wire argon arc welding (PAW-GTAW) technology. After the provincial-level scientific and technological achievement evaluation, the technical level has reached the international standard in the field of deep cryogenic container manufacturing. Choose ZJ Special Equipment, and let's create brilliance together!