Oil tank and sewage tank combined natural gas hermetic recovery device

The utility model relates to an oil tank and sewage tank combined natural gas hermetic recovery device, comprising an oil tank, a sewage tank, a separator, a filter, an effusion meter, a self-supporting adjustable valve (or an electric adjustable valve), a water sealing tank, a differential pressure transmitter, a compressor, a comprehensive control cabinet, an electromagnetic valve, a mechanical valve, a hydraulic safety valve and a U-tube differential pressure meter. The utility model is characterized in that the recovery pipe of the oil tank volatilization gas is connected with the air inlet pipe of the sewage tank, the inlet of the water sealing tank, the pressure-leading pipe at the inlet of the comprehensive control cabinet, and the separator. The outlet of the separator is connected with the compressor, the outlet of the compressor is connected with the effusion meter, and the outlet of the effusion meter is connected with the exterior transfusion pipelines. The air inlet pipes of the oil tank and the sewage tank are simultaneously connected with natural gas complemental pipelines, the coming air source of the nature gas complemental pipelines enters the separator, the outlet pipe of the separator enters the filter, the outlet pipe of the filter enters the effusion meter, and the outlet pipe of the effusion meter enters the adjustable valve (or the electric adjustable valve). The natural gas can simultaneously enter into the oil tank and the air inlet pipe of the sewage tank through the pressure adjustment, and the whole process is a natural gas hermetic recovery pipeline.