Founded in 19 19, API is the first national business association in the United States and one of the earliest and most successful chambers of commerce in the world. Api gravity is the largest trade association in the oil and gas industry in the United States. It represents about 400 enterprises involved in the production, refining and distribution of the petroleum industry. The main functions of the association include publicity and negotiation with the government, legal circles and regulatory agencies; Study the impact of industry on economy and environment, establish industry standards and certification, and carry out outreach education and publicity. API funds and conducts many researches related to petroleum industry.