API（(American Petroleum Institute)） is the abbreviation of the American Petroleum Association. The purpose of publication of the API610 standard is to provide a procurement specification to facilitate the manufacture and procurement of centrifugal pumps.

API610 requires minimum requirements for centrifugal pumps used in the petroleum industry, heavy chemical industry, and natural gas industry. The centrifugal pump according to API610 standard is often called API pump. There are 18 kinds of API pumps, OH1, OH2, OH3, OH4, OH5, OH6, BB1, BB2, BB3, BB4, BB5, VS1~VS7. All materials for API pump are selected according to API 610 standard. The API pump runs continuously for at least 3 years with high reliability. API pump has a wide range of applications. The pump types involved are three kinds of pumps, namely cantilever type (Overhung), both ends support type (Between Bearings) and vertical suspension type (Vertical Suspended).

The difference between API pump and ordinary pump:
1. Strict material requirements;
2. For maximum allowable working pressure, the pump pressure is high (2MPa or above), and the pressure of pump pressure is required to be long (30 minutes)；
3. Vibration requirements higher than the national standard (all 4.5 mm/ below)；
4. Floor design: the unit is all located on the bottom board, horizontal pump design collecting tank;
5. The inlet and outlet flange is designed to connect through the bolt；
6. Dynamic balance requirement is high, according to G2.5 level;
  7. The factory acceptance standard is strict, the QC document is clear and clear, reflecting the whole process of the whole pump from design to manufacture