The LNG storage tank is a double-walled structure, consisting of the inner tank, outer tank, internal and external supports, insulation layer, pressure safety system, vacuum pump, pipeline system, etc. All vacuum-insulated structures rely on vacuum. Due to the high degassing rate and suction resistance of the insulation space materials, and the inability to exceed high baking temperatures for sealing materials without slow degassing, suction can be difficult. To achieve the required vacuum level within the designed suction time, in addition to the vacuum pump and suction process, it also relates to the flow area of the annular suction pipe. To ensure a high vacuum level and improve the suction rate, a vacuum pump is installed at both ends of the equipment. One vacuum pump is composed of three suction pipes, placed in the lower half of the annular space and extending from the bottom, and the other vacuum pump, also with three suction pipes, is placed in the upper half of the annular space and extends from the top, with the two groups of suction pipes intersecting and overlapping along the length of the tank. By increasing the flow area of the suction pipes and using various auxiliary methods such as heating and nitrogen displacement, the vacuum achievement time for the annular insulation space with a volume of 100 m³ is reduced to one-third of the conventional structure.

Liquefied Natural Gas (LNG) storage tanks consist of the tank body, instruments, pipelines, valves, etc. These tanks are designed with two types of liquid inlet methods, upper and lower, allowing for selection based on actual conditions.

The inner tank of the liquefied natural gas storage tank is equipped with a safety system device featuring dual safety valves. Under normal operation, one set is in working condition while the other is on standby. In the event that the working safety valve trips, the manual pressure relief valve is immediately opened to release pressure below the tank's working 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 featuring excellent fire and static electricity prevention structures. Additionally, the safety relief ports on the housing are fully guaranteed to ensure the entire equipment's safety and reliability. The low-temperature pipeline is centrally extracted for ease of operation and control, and the extraction outlet is designed with a Duralumin pipe structure to accommodate low-temperature requirements and minimize stress caused by thermal expansion and contraction in the pipeline, ensuring the tank's safety. The vacuum extraction valve is equipped with three stages of “OFormed ring seal ensures reliable interlayer sealing, made entirely of stainless steel with a compact size. The top design of the Liquefied Natural Gas (LNG) storage tank features a hanging structure for easy transportation, lifting, and installation. The unique manhole design ensures the cleanliness inside the tank when the container is sealed. Vacuum isolation valves and combined vacuum gauges are used on the LNG storage tank for easy measurement of the interlayer vacuum and maintenance, extending the tank's lifespan and improving its quality. The LNG storage tank is equipped with a level gauge and pressure gauge for on-site display of liquid level and pressure. The interlayer insulation material is high-quality domestic pearl sand, with the performance parameters of the pearl sand as follows:

Serial Number Indicator Name Unit Index 

1 Loose Bulk Density Kg/m3 50－60 

2 Particle size mm 0.1－0.2 Not less than80% 

3 Thermal Conductivity (at atmospheric pressure),Temperature310-77k） W/m.k.s ＜0.026 

4 Moisture content(Weight) % ＜0.1 

5 Unexpanded Rate % ≤1 

6 Temperature ℃ －200℃～600℃ 

7 PHValue   6.5～7.5 

Section 3: Inspection, Testing, and Acceptance

1Inspect the inner cylinder material; usage is permitted only upon passing inspection.

2All welds are to be inspected.GB150.1～150.4-2011Inspection of standards and drawings is required; upon passing inspection.A、BWeld-like seam100Gamma-ray inspectionC、DWeld-like seam100Percent permeability testing with a detailed test report provided

3After the cylinder assembly is completed, pleaseGB150.1～150.4-2011Standards and drawings require inspection of geometric dimensions, pipe end orientations, and shape deviations.

4After inspection, perform a pneumatic pressure test and issue a pressure test report. Upon passing the pneumatic pressure test, evacuate the vacuum. Once the vacuum level meets the requirements, conduct a helium leak test.

5After interlayer leak detection passes, fill with pearlescent sand and then vacuum, achieving a vacuum degree ofGB/T18442-2011Final sealing vacuum requirements.

Section 4: Technical Documents

1Upon contract signing, the seller shall provide the buyer with the following technical documents:

⑴ Certificate of Product Quality for Equipment1Set (supplied with equipment)

Including: Material Certification of 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, Special Equipment Manufacturing Supervision and Inspection Certificate (Local Inspection Authority), Product Brand Copy

As-Built Drawings Various1Piece (supplied with the equipment)

Strength Calculation Sheets1Piece (provided with the equipment)

⑷ User manuals1Piece (provided with the equipment)   

Equipment process diagram and basic reference diagram1Piece (Contract)7Available today (subject to availability)

⑹ Certificate of conformity for matching products, instrument calibration report 1Piece (supplied with the equipment)