Heze Boiler FactoryLimited Company

Equipment Name: Natural Gas Storage Tank --- Liquefied Natural Gas Storage Tank --- Natural Gas Storage Tank (Function Description)

Contact Information:    AtManager

Manufacturer:Huzhou Boiler FactoryLimited Company

This article analyzes the hazardous characteristics of low-temperature liquids and, in conjunction with various gas supply modes for low-temperature storage tanks, briefly outlines their basic requirements and key safety usage points.

An LNG storage tank is a jacketed vacuum powder-insulated pressure vessel specifically designed for storing and supplying low-temperature liquefied gases (such as liquid nitrogen, liquid oxygen, liquid argon, liquid carbon dioxide, etc.). It has been widely used in both industrial production and daily life.

1. Analysis of Low-Temperature Liquid Hazardous Characteristics

Low-temperature liquids possess hazardous characteristics such as lower boiling points, greater expansiveness, strong asphyxiating properties, and strong oxidizing properties.

1.1 Boiling points of low-temperature liquids at 101.3 KPa pressure: Liquid nitrogen at -196°C, liquid oxygen at -183°C, and liquid argon at -186°C. Contact with the human body can cause severe frostbite to the skin and eyes. In cases of minor leakage or internal leakage in valves, these liquids absorb heat from the surrounding environment, causing rapid condensation and frost formation at the leak point, which can lead to freezing in severe cases.

Low-temperature storage tank

1.2 Low-temperature liquids absorb energy from the surrounding environment due to high heat or large leaks, causing their volume to expand rapidly as they vaporize. At 0℃ and a pressure of 101.3 KPa, the volume of gas produced from 1L of low-temperature liquid upon vaporization is: nitrogen at 674L, oxygen at 800L, and argon at 780L. Inside sealed containers or pipelines, the increase in internal pressure due to the vaporization of low-temperature liquids can easily lead to overpressure explosions.

1.3 In the environment surrounding low-temperature storage tanks, the leakage of low-temperature liquids can easily cause vaporization, leading to rich gas areas. High concentrations of nitrogen, argon, or carbon dioxide can readily cause asphyxiation injuries. Additionally, high oxygen concentrations can result in oxygen enrichment injuries.

1.4 Oxygen is a powerful oxidizer with extremely strong oxidizing properties. When liquid oxygen is in close proximity to combustible materials, it can easily ignite upon contact with an open flame. Contact with combustible materials can cause explosions due to vibrations or impacts. A mixture of liquid oxygen and combustible materials poses a potential explosion hazard. Liquid oxygen can adhere to clothing fibers, and upon ignition, it can cause a flash fire, posing a risk to personal safety.

2. Low-Temperature Storage Tank Gas Supply Mode and Basic Requirements

The supply mode of low-temperature storage tanks primarily varies depending on the application and user requirements.

We offer: high-pressure gas cylinder refilling, low-temperature insulated gas cylinder packaging, centralized gas supply through pipelines, and low-temperature liquid spray supply, etc.

Huzhou Boiler Factory Co., Ltd.

Liquefied Natural Gas (LNG) storage tanks consist of the tank body, instruments, pipelines, valves, etc. These tanks are equipped with two types of liquid inlet methods, upper and lower, which can be selected and used according to actual conditions.

The inner tank of the Liquefied Natural Gas (LNG) storage tank is equipped with a safety system device featuring dual safety valves. Under normal operation, one set is in operation while the other is on standby. If the safety valve in operation trips, the manual pressure relief valve is immediately opened to relieve pressure below the tank's operating pressure. Simultaneously, the safety device is swiftly switched to the standby system using the manual handle, effectively ensuring the tank's safety. This safety system device consists of safety valves, explosion-proof devices, vent valves, and three-way ball valves, not only reducing pipeline welding but also having excellent fire and static electricity prevention structures. Additionally, the safety relief openings on the housing are fully guaranteed to ensure the overall safety and reliability of the equipment. The low-temperature pipeline is centrally extracted for ease of operation and control, and the extraction outlet is designed with a Duralumin structure to meet low-temperature requirements and reduce stress on the pipeline due to thermal expansion and contraction, ensuring the tank's safety. The vacuum pump valve uses three "O" rings for sealing, effectively ensuring the reliability of the sandwich sealing, and is made entirely of stainless steel with a compact size. The top of the LNG storage tank is designed with a suspended structure for ease of transportation, lifting, and installation. The unique manhole design ensures the cleanliness of the interior when the inner container is sealed. Vacuum isolation valves and combined vacuum gauges are used on the LNG storage tank for easy measurement of the sandwich vacuum level and maintenance, extending the tank's service life and improving its quality. The LNG storage tank is equipped with a level gauge and pressure gauge for local display of liquid level and pressure. The sandwich insulation material is high-quality domestic pearl sand, with the following performance parameters:

Serial Number Indicator Name Unit Indicator

Loose Bulk Density: 50-60 Kg/m³

2 Grain size mm 0.1-0.2, not less than 80%

Thermal Conductivity (atmospheric pressure, temperature 310-77K) W/m·K·s < 0.026

Moisture Content (Weight) % < 0.1

5 Non-inflated Rate % ≤ 1

6 Temperature ℃ -200℃ ~ 600℃

7 pH Level: 6.5-7.5

Section 3: Inspection, Testing, and Acceptance

1. Inspect the inner cylinder material and only use it after passing the inspection.

2. All welds are inspected according to the GB150.1-150.4-2011 standards and drawings. Upon passing the inspection, A and B class welds undergo 100% X-ray inspection, C and D class welds are subjected to 100% penetrant testing, and a test report is issued.

3. After the cylinder assembly is completed, inspect the geometric dimensions, pipe end orientations, and shape deviations in accordance with the GB150.1-150.4-2011 standards and drawings.

4. After passing the inspection, conduct a pressure test and issue a pressure test report. Once the pressure test is approved, evacuate the air, and upon achieving the required vacuum level, perform a helium leak test.

5. After the interlayer leak test passes, fill with pearl sand and then evacuate to create a vacuum. Seal the vacuum once the vacuum level meets the requirements of GB/T18442-2011 standard.

Section 4: Technical Documents

1. After the contract is signed, the seller shall provide the following technical data to the buyer:

⑴ Each set of equipment quality certificates (provided with the equipment)

Including: Material Certificate for Main Pressure Components, Bill of Materials, Structural Dimension Inspection Report, Inspection Plan, Product Compliance Certificate, Pressure Vessel Product Data Sheet, Welding Records, Non-Destructive Testing Report, Pressure Test Report, Supervision and Inspection Certificate for Special Equipment Manufacturing (Local Inspection Authority), Product Brand Copy

⑵ As-built drawings, 1 set each (provided with the equipment)

Each set of strength calculation documents (provided with the equipment)

⑷ 1 instruction manual per unit (provided with the equipment)

1 set of equipment process diagram and 1 basic reference diagram (to be provided within 7 days after contract signing)

⑹ Certificate of conformity for matching products, 1 each; Instrument calibration report, 1 each (provided with the equipment)