60m3Horizontal Low-Temperature Liquefied Natural Gas Storage Tank Technical Specifications 

（2）Tank Pipeline Valve Instrument List (Domestic High-Quality Products)

Partial User Cases:

Liquefied Natural Gas (LNG) Storage Tank

Low-temperature Liquefied Natural Gas Storage Tanks, Manufacturer of Liquefied Natural Gas Storage Tanks:Heze Boiler Factory Co., Ltd., Manager, Mr. Yu。

LNG above-ground storage tanks come in five forms: the single-vessel tank is the most common, available in single-walled and double-walled versions. Due to safety and insulation concerns, single-walled tanks are not used for LNG storage. The outer shell of the double-walled single-vessel tank is made of carbon steel, which cannot withstand the low temperatures of LNG or other gases, primarily serving to secure and protect the insulation layer. Single-vessel tanks are generally suitable for use in areas far from populated zones and prone to less catastrophic damage, as their structural characteristics require significant safety distances and land area. The design pressure of single-vessel tanks typically ranges from kPa, with operating pressure at 12.5kPa. For large-diameter single-vessel tanks, the design pressure is correspondingly lower, with BS7777 specifications setting it at less than 14kPa, making it challenging to achieve when the tank diameter is 70-80m, and the maximum operating pressure is around 12kPa. The lower design pressure necessitates a more powerful recovery and compression system for the evaporated gases, increasing investment and operational costs. While single-vessel tanks have a relatively lower investment and shorter construction period, their tendency to leak is a significant issue. In accordance with regulations, the safety distance between single-vessel tanks is substantial, and firebreaks must be set up, adding to land and firebreak investment. There should be no other critical equipment nearby. Consequently, stringent safety inspections and operation requirements are necessary.

Liquefied Natural Gas (LNG) Storage Tanks, Low-Temperature LNG Storage Tanks, Manufacturer of LNG Storage Tanks:

Huzhou Boiler Factory Co., Ltd., Manager Yu。

(1) A trench with a depth of 1.5 em, length of 20,000 cubic meters, and width of 2 meters is constructed on the foundation of the storage tank. Figure 3 shows the electrolytic ion grounding electrode, and Figure 4 shows the installation diagram of the electrolytic ion grounding electrode. (2) Wipe the grounding electrode clean with a dry cloth, ensuring no oil residue; inject clean water into the ion release holes at the top, middle, and bottom of the grounding electrode. (3) Mix the GAF powder grounding improvement agent with water, and place it at the bottom of the trench. (4) Place the grounding electrode at a certain angle at the bottom of the trench, covering the top with the improvement agent. (5) Wrap the grounding electrode lead wire with insulating tape and connect it to the grounding main using a hot melt welding method. 5 Static Grounding Setting When LPG is injected into the storage tank, the liquid flow causes charge separation, and when the charge accumulates to a certain extent, static discharge occurs. Since static discharge is completed within nanoseconds, the peak current can reach dozens of amperes, resulting in a tremendous instantaneous power and severe destructive force. To avoid static hazards: First, limit the flow speed of flammable liquids to greatly reduce the generation and accumulation of static electricity; second, ensure proper static grounding. Static grounding provides a path for the release of static charges by grounding. The grounding circuit must be reliably connected; otherwise, spark discharge will occur at points of poor contact. The specific method is: weld grounding bolts on the inner wall of the storage tank, connect them to the outer wall metal body through a 70 mm² insulated copper core wire, and release the static electricity. The static grounding connection is shown in Figure 5. Figure 5 Static Grounding Connection Wall 6 Grounding Test Results According to GB 50057-2010, Article 4.3.10, the impulse grounding resistance value at each grounding point should not exceed 30 Ω. According to GB 12158-2006, Article 6.1.2, to dissipate static charges as quickly as possible in static hazard areas, all objects that are conductors of static electricity must be grounded. The grounding resistance value of each group of dedicated static grounding bodies generally should not exceed 100 Ω. In areas with high soil resistivity, such as areas with a resistance rate of 1000 Ω, the grounding resistance value should also not exceed 1000 Ω. After the lightning protection grounding project is completed, the measured grounding resistance value is 0.8 Ω, and the grounding lead lines are well connected to the grounding main, meeting the lightning protection grounding requirements.

Liquefied Natural Gas Tanks, Cryogenic Liquefied Natural Gas Tanks, Manufacturer of Liquefied Natural Gas Tanks:

Heze Boiler Factory Co., Ltd., Manager Yu。

Current transformer secondary circuit open circuit differential protection. The differential protection output is locked or unlocked by selecting the control word when the secondary circuit of the current transformer is open-circuited and the differential current is not significant. When the secondary circuit of the current transformer is open-circuited and the differential current is low, the differential protection device emits an alarm signal, notifying the dispatch personnel to shut down the transformer for maintenance by reversing the load. This prevents the main transformer from tripping due to the secondary circuit opening of the current transformer. If the differential current increases to the open-circuit differential protection setting (usually the rated current of the transformer, P), the open-circuit differential protection is activated. Thus, the transformer's differential protection operates, causing the main transformer to trip, and the protection device can correctly disconnect the fault current, preventing the accident from escalating. This is a compromise solution that balances the advantages and shortcomings of the first two methods, achieving good results. For the 1st 110kV substation's 3rd main transformer (capacity 63 MVA, voltage ratio 110kV/10.5kV, connection type YNdll, primary current transformer ratio 600A, secondary current transformer ratio 4000, the differential protection settings are as follows: differential quick-break current setting, ..=4.4(A), differential protection start-up setting, ..=0.28(A), ratio braking coefficient setting K=0.5, second harmonic braking coefficient 0.15, open-circuit differential protection setting 0.8. One day at 6:42, an alarm was reported at the 1st substation's back-end, indicating that the secondary circuit of the 3rd main transformer's differential protection current transformer was open-circuited, with a sudden change in current of 0.08A and a phase difference differential current of 0.056A. After contacting the dispatch personnel to reverse the load and shut down the power, the equipment was inspected and found to be loose terminal blocks on the SF6 enclosed switchgear. After tightening the terminal blocks, the fault was eliminated.