Air tightness must meet standards. The oil and gas recovery testing requirement for gas stations in Jilin Province is that the air tightness must meet the standard. The air tightness must meet the standard. Nitrogen should be filled into the oil tank system so that the air pressure of the oil tank system reaches 500Pa. Jilin Province, referred to as "Ji", is a provincial-level administrative region of the People's Republic of China and the provincial capital of Changchun.