About 2000m ³ LNG tank body test

2000m ³ General requirements for LNG tank body test and inner cylinder test

1. Strength test pressure = 7380mmh2o + 25kpa gas phase pressure, hold the pressure for 1H without leakage and abnormal deformation; Air tightness test pressure = 7380mmh2o + 20KPa gas phase pressure, no leakage and abnormal deformation for 24h

2. During the water pressure test of the inner cylinder, the container should be communicated with the atmosphere during filling and draining. During the test, the settlement of the foam glass brick insulation layer and the concrete foundation should be observed.

3. Before water filling and pressurization of gas phase space, check whether the inner cylinder anchor belt is abnormal; Slightly tighten the nut of the inner cylinder anchor belt and lock the nut when there is still 1 / 3 turn

4. During the test, the tightness of all welds on the cylinder wall shall be observed with naked eyes. All welds, including the fillet weld between the cylinder and the bottom plate, shall be qualified without leakage and abnormal deformation.

Air tightness and strength test of inner cylinder

1. Close all air outlets of the tank with a blind plate. After the tank is filled to the maximum liquid level, slowly fill the tank with air pressure to 25kpa to conduct the inner cylinder strength air pressure test; Keep the test pressure for 1 hour, and it is qualified if there is no leakage and abnormal deformation

2. Reduce the pressure to 20KPa and maintain the pressure. Check all welds on the water surface with soapy water. It is qualified if there is no leakage

3. Slowly release the gas phase pressure on the water level of the inner cylinder, remove the blind plate at the air outlet of the lower shell of the pressure safety valve, slowly fill the inner cylinder with air pressure to 25kpa again, verify the opening of the pressure safety valve, and recheck if it is unqualified

4. Open the vent to keep the pressure inside and outside the cylinder balanced, drain water slowly, and retighten the anchor bolts after the container is drained.

Filling pearlescent sand:

1. The pearlescent sand shall be dry before filling. The pearlescent sand shall be filled from the pearlescent sand filling port. A wooden stick shall be prepared in advance for the filling part. During filling, the wooden stick shall be pumped and tamped, and the outer wall of the tank shall be knocked with a rubber hammer to ensure the best compactness of pearlescent sand filling.

2. Before pearlescent sand filling, the interior of the tank shall be fully inspected by all quality inspection departments, and can be carried out only after confirmation and signature.

Foundation settlement observation

This work is coordinated by the Civil Engineering (Foundation) construction unit. An observation point shall be set at the lower part of the tank wall every 10m. The elevation shall be measured with a level gauge. The number of observation points is 4. Fill water to 1 / 2 of the tank height first, observe the settlement, compare it with the observed data before water filling, and calculate the actual uneven amount. It is required that the height difference of each measurement point shall not exceed ± 2mm, and the maximum settlement shall be less than 5mm. When the design allowable differential settlement is not exceeded, continue to fill water to 3 / 4 of the tank height for observation. When the allowable differential settlement is not exceeded, continue to fill water to the maximum operating liquid level for observation after water filling and 24 hours. When there is no obvious change in settlement, drain water; When the settlement changes obviously, the maximum liquid level shall be maintained for regular observation every day until the settlement is stable