Natural gas is widely recognized as a clean, environmentally friendly, and safe high-quality energy source. Once liquefied, natural gas reduces in volume by about 600 times, which greatly benefits storage. Storage of liquefied natural gas (LNG) is done using atmospheric-pressure, low-temperature tanks. Let's discuss the unique features of these LNG storage tanks.

What are the special requirements for LNG low-temperature storage tanks?

1.Low-temperature resistance

The boiling point of liquefied natural gas (LNG) at atmospheric pressure is -160°C. LNG is stored at low temperatures and atmospheric pressure, lowering the gas temperature below its boiling point. This results in storage tanks operating at slightly higher pressure than atmospheric, which, compared to high-pressure, ambient-temperature storage, significantly reduces tank wall thickness and enhances safety performance.

Therefore, LNG requires storage tanks with excellent low-temperature resistance and superior insulation properties.

2.High safety requirements

Due to the storage of low-temperature liquids inside the tank, in the event of an accident, the refrigerated liquid would volatilize in large quantities, with the vaporization amount being approximately 300 times that of the original refrigerated state. This would form an air mass that would automatically detonate in the atmosphere.

Therefore, standards like API, BS, etc., require the use of double-walled tank structures, employing the containment concept. In the event of a leak in the first layer of the tank, the second layer can completely seal off the leaked liquid and evaporated gases, ensuring storage safety.

3.Special Material

The inner shell requires low-temperature resistance, typically made of 9Ni steel or aluminum alloys, while the outer shell is prestressed reinforced concrete.

4.Insulation measures are stringent

The temperature difference between inside and outside the tank can reach up to 200°C. To maintain the internal temperature at -160°C, the tank must have excellent insulation properties, filled with high-performance insulation material between the inner and outer tanks. The insulation material at the bottom of the tank must also have sufficient pressure-bearing capacity.

5.Excellent seismic performance

The seismic resistance requirement for general buildings is to crack but not collapse under specified seismic loads. To ensure the safety of storage tanks under unexpected loads, they must possess excellent seismic performance. For LNG storage tanks, the requirement is to neither collapse nor crack under specified seismic loads.

Therefore, the selected construction site generally avoids seismic fault zones, and anti-seismic tests must be conducted on the storage tanks before construction. This analysis evaluates the structural performance of the tanks under dynamic conditions, ensuring that the tank body remains undamaged under the given seismic intensity.

6.Strict construction requirements

Tanks must undergo 100% magnetic particle testing (MT) and 100% vacuum leak testing (VBT) on welds. Select insulating materials meticulously, and adhere to the prescribed procedures during construction. To prevent cracks in concrete, post-tensioned prestressed construction is employed uniformly, with stringent control over the verticality of the tank walls.

LNG storage tanks are essential storage containers for LNG fueling stations, an indispensable component of such stations. As a professional in the LNG industry, do you truly understand them? Let's delve into a detailed introduction below:

1. Form of packing

LNG tanks typically come in vertical and horizontal types. Vertical tanks have the advantage of occupying less space and being easy to use, as the gravity difference reduces the power consumption of submersible pumps, saving electricity. However, vertical tanks generally exceed 10 meters, which can cause fear among nearby residents, making them unsuitable for urban areas. Horizontal tanks are the most commonly used type, but they require more space and have safety distance requirements from surrounding structures and facilities. According to GB50156, this increases the design complexity.

2. Insulation type

Common insulation forms for LNG tanks include high vacuum multi-layer wrapping insulation and pearl sand powder insulation. The latter is more common in practical applications due to its lower cost.

3. Materials

The container is made of high-quality Austenitic stainless steel 0Cr18Ni9 sheet or imported 304 sheet; the outer container is made of high-quality carbon steel Q345R plate.

4. Safety Protection System

The safety protection system consists of tank accessories including: pressure gauges, level gauges, fully enclosed safety valves with one in use and one in reserve at the root, overflow outlets, bursting discs.

5. Filling Form

LNG tanks can be filled via the top or bottom. Top filling uses cold liquid to liquefy the BOG gas inside the tank. Both methods can be used, and the choice during the unloading process depends on the on-site conditions. It's quite complex and cannot be explained in just a few sentences. Those with questions are welcome to private communicate.

6Level Conversion

LNG液位换算质量容积及质量需要按照储罐厂家提供的数据，结合液厂的气质报告数据综合确定。

7Technical Requirements

General technical agreements require LNG tank design pressure.0.8MPA, designed for temperatures down to -196°C, with a daily evaporation rate not exceeding 0.20%. The actual working pressure of the tank is generally less than 0..8MPA's, the operating temperature is generally determined by the liquid's quality, around -100°.

A seemingly simple white storage tank has deep waters. How to choose the right tank that minimizes investment while meeting usage requirements, how to use the tank efficiently to reduce losses at the gas station, and cut down on maintenance costs? Welcome to private message for details.