1.2.3 LNG Storage Tank Gas Supply Process:

All valves of the tanks to be pressurized are closed, except for the root valve and the emergency shutdown valve.

2. Open the lower liquid inlet valve of the low-temperature storage tank, as well as the pressure increase liquid and gas phase valves, and check that both valves of the pressure increase vaporizer are open.

3. Open the low-temperature cutoff valve before the gasifier, the normal temperature flange ball valve after the gasifier, and all valves required to be opened in the pressure regulation system.

4.A. A single storage tank is sufficient to meet the gas supply requirements when the gas supply volume is less than 1000-2000 Nm3/h.

5. Liquid Output:

5.1 When the tank pressure rises above 0.15 MPa higher than the outlet pressure, slowly open the liquid outlet valve to commence the gas supply operation.

5.2 Record the liquid storage tank number and the start of gas supply time.

5.3 Pay close attention to the liquid level, pressure changes, and flow and pressure variations at the exit when supplying gas.

1.2.4 Self-pressurization Operation Procedure for LNG Tanks

1. During manual operation, open the valves: the boost liquid phase valve, the boost gas phase bypass valve, and the vaporizer inlet valve, allowing LNG to flow directly into the self-boosting vaporizer. After vaporization, it enters the LNG storage tank. At this point, closely monitor the pressure; close the boost liquid phase valve when the pressure in the LNG storage tank reaches the required level.

2. Important Notes:

(1) During operation, the LNG low-temperature tank must ensure the upper liquid level is ≤90% and the lower liquid level is ≥15%.

(2) When manually operating the self-pressurizing system, unauthorized personnel are strictly prohibited from leaving the site.

(3) When the self-pressurizing system is in operation, the pressure-reducing system should be turned off.

3. Important Notes:

(1) During operation, the LNG tank must maintain a liquid level of ≥15%.

(2) When operating manually, the site must be strictly supervised at all times.

1.2.5 Risk Analysis and Countermeasures

When loading and unloading LNG tankers, operators should wear masks, static-free work clothes, and anti-freezing gloves, etc.

2) During LNG tanker unloading, the vehicle must not move to prevent the disconnection of the loading and unloading hoses, which could lead to a large-scale LNG leak.

3) When LNG is present in the pipeline, both ends' valves cannot be closed simultaneously.

4) Absolutely no touching or stepping on low-temperature pipelines and equipment.

6) Under no circumstances should water, oil, and mechanical impurities enter the pipeline to avoid blockages.

7) Absolutely no敲打, torch heating, or water spray on the frozen sections.

8) To ensure the safety of the working environment, operators must wear proper protective equipment. Static electricity from the human body must be neutralized before entering the station. Open flames are strictly prohibited within the station's operational area, as well as the use of non-explosion-proof tools and electronic devices.

9) Strictly adhere to the operation ticket system, follow the steps outlined on the operation ticket. On-site operators must consist of at least two people: one to operate and one to supervise, ensuring operational safety.

10) Conduct safety education before operation, ensure on-site safety precautions are in place. In case of danger, know how to evacuate and how to control the situation.

1.2.6 Procedure for LNG Tank Maintenance and Care

Operations technicians at liquefied natural gas stations must be familiar with the structure and principles of the storage tanks and strictly follow the operational procedures for liquefied natural gas-related activities.

2. Operators of liquefied natural gas must be familiar with the performance and principles of storage tank accessories (pressure gauges, level gauges, temperature gauges, vacuum test valves).

3. LiquefiedNatural Gas Storage TankThe outer cylinder is an external pressure vacuum vessel; welding operations are strictly prohibited under negative pressure.

4. Regularly inspect the outer shell of the storage tank for signs of icing. If icing is detected, promptly report to the on-duty supervisor and station master. The on-duty supervisor or station master should immediately contact the manufacturer to identify the cause and address the issue. During the resolution process, closely monitor the changes in icing. If the incident shows signs of escalation, immediately initiate tank emptying or halt the filling operation, and close the relevant emergency shut-off valves for inlets and outlets.

5. Regularly inspect the storage tank's connecting pipes, valves, etc., for frost formation. Report any issues to the on-duty supervisor immediately, who will then arrange for personnel to address the situation.

6. Regularly inspect the tank's pressure gauge, level gauge, and thermometer to observe if the readings are normal.

7. Regularly inspect the sealing performance and operation of the connecting valves to ensure normal functioning.

8. Regularly inspect and calibrate safety valves, pressure gauges, level gauges, and thermometers according to regulations, ensuring proper operation and timely updating of equipment inventory records.

9. Regularly carry out anti-corrosion treatment on the storage tank's outer cylinder and perform visual cleaning and maintenance on the pressure gauge, level gauge, and thermometer of the storage tank.

10. Regularly perform rust removal and anti-corrosion treatments on the storage tank's pressure and level control instruments, as well as the control ball valves, which are prone to rust.

11. Conduct annual or on-demand vacuum level inspections of the storage tanks to monitor their operational status.