Operation Instructions

Utilize Security Management

(1) The user unit shall, in accordance with regulations, apply for and obtain a "Special Equipment Use Registration Certificate" from the department responsible for special equipment use registration at the location within 30 days before or after the product is put into use.

(2) Users shall comply with the relevant requirements of the "Special Equipment Operation and Management Regulations" for safety management of this product. They should appoint a safety management supervisor, safety personnel, and operational staff, establish various safety management systems, formulate operational procedures, and conduct inspections.

2. Pre-Use Preparation

Tanks and associated pipelines are installed and positioned; upon passing the acceptance inspection, preparations for use are made.

Tanks must be purged with dry nitrogen and pre-cooled with liquid nitrogen prior to first use. The purge pressure should not be less than 0.2 MPa.

Prior to blowing, loosen the joints at both ends of the differential pressure (level) gauge, and fully open valve A9 of the differential pressure (level) gauge assembly. Check if there is moisture in the exhaust gas flow. If moisture is present, continue blowing until it stops. Tighten the joints at both ends of the differential pressure (level) gauge and close the balance valve to put the differential pressure (level) gauge into normal operating condition.

Before the tank is initially filled with LNG, replace the liquid nitrogen or nitrogen inside the tank with LNG gas. First, open drain valve A-6 to vent the nitrogen, then close the drain valve. Open vent valve A-12 and transfer LNG gas from the tank container to the tank via the unloading platform. When the tank pressure reaches 0.1-0.2 MPa, close vent valve A-12, stabilize for 3 minutes, then open drain valve A-6 to vent. Repeat this process 2-3 times, and the replacement is complete. Use a flammable gas detector or take a sample of the vented air for ignition testing to check the replacement level.

During the first LNG filling, the tank should be pre-cooled or checked for previous pre-cooling. The liquid filling rate must be strictly controlled and operated slowly. First, slowly open the upper filling valve A-2, and transfer LNG from the tanker to the tank via the unloading platform. Due to the lagging vaporization process when LNG is transferred to the tank, closely monitor the rate of pressure increase inside the tank. The liquid filling amount must be minimal. When the pressure reaches 0.3 MPa, open the gas exhaust valve A-12 to reduce pressure, and close the upper filling valve A-2 if necessary. Pre-cool the tank through continuous filling and exhaust. After a period of controlled filling, when the tank pressure stabilizes and the liquid level gauge indicates a certain level, gradually increase the opening of the upper filling valve A-2 and open the lower filling valve A-1.

3. Initial Filling Operation for Storage Tank

(1) Open the upper and lower inlet valves A-2 and A-1, filling simultaneously from top and bottom. During the filling process, monitor the differential pressure (level) gauge readings. Open the full indicator valve A-4, vent the gas in the storage tank, and immediately close the full indicator valve A-4 upon the release of LNG gas.

(2) When the tank is filled to more than 50% of its capacity, the lower liquid inlet valve A-1 should be closed.

(3) When the tank is filled to over 85% of its capacity, close the inlet valve A-2, stop filling for 5 minutes to allow the liquid level in the container to stabilize, then reopen the inlet valve A-2 to continue filling. Open the full indicator valve A-4 and keep filling until liquid starts to flow from the full indicator valve A-4. Immediately close the full indicator valve A-4 and shut off the inlet valve A-2 to cease filling.

4. Tank Refueling Operation Procedure

Upon the first formal filling, the vapor pressure inside the tank should be as low as possible during subsequent refills.

(2) Fill both upper and lower sections simultaneously. When the differential pressure (level) gauge indicates approximately 50% of the tank's volume, close the lower inlet valve A-1. At approximately 85% of the tank's volume, close the upper inlet valve A-2, stop filling for 5 minutes to stabilize the liquid level in the container, then open the upper inlet valve A-2 to continue filling, and open the full indicator valve A-4. Continue filling until liquid starts to discharge from the full indicator valve A-4. Close the full indicator valve and simultaneously close the upper inlet valve A-2, then stop filling.

(3) Monitor the pressure gauge and differential pressure (level) meter during filling. (If the pressure rises above the filling pressure or nears the safety valve pressure, the exhaust valve A-12 must be opened to release an appropriate amount of gas from the storage tank to relieve pressure.)

(4) Fill out the operation record form.

5. Tank Pressurization Operation Procedure (Valves and equipment for this stage are to be provided and installed by the owner)

Using a supercharger can increase the pressure inside the tank. The boost pressure is controlled according to the draining requirements and must not exceed the tank's maximum working pressure. The boost system of this tank is controlled by a pressure regulating valve, with the product pressure adjustment range being 0.2 to 0.8 MPa. The boost operation procedure is as follows:

Check if the pressure gauge is in working condition.

(2) Confirm that the boost system pressure regulating valve is open.

(3) Gently open the shutoff valve.

(4) When shutting off the drain, close the shut-off valve to prevent an increase in tank pressure.

(5) Important Notes:

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

2) When operating the boost system, safety must be observed, closely monitored, and personnel are strictly prohibited from leaving the site unauthorised.

6. Tank Pressure Reduction Procedure

Open valve A-12 to reduce the vapor pressure inside the storage tank to no more than the pressure set by the pressure regulator, then close valve A-12.

7. Tank Discharge Operation Procedure

Check that the tank's pressure gauge, differential pressure (level) gauge, flammable gas detector, and safety valve are operating normally.

(2) Inspect the pipeline valves, pressure gauges, and safety valves to ensure they are in normal working condition.

(3) Prepare all explosion-proof tools and wear protective gear.

(4) Inspect the IV line and open drain valve A-6.