What is API Pump? | How does API Pump work?

What is an API Process Pump?

API stands for American Petroleum Institute. This standard is used to design special types of pumps. An API pump is a type of pump designed to fulfill the API 610 Standard for hydrocarbon processing. The API pumps have various types. These pumps use multiple pumping methods.

The API 610 standard is most usually used for centrifugal pumps, but API processing pumps come in a variety of types, including vertical turbo pump, vertical in-line pump, multistage pump, horizontal split pump, or suction pump.

The API pumps are specially used for the gasoline, petroleum industry, and other hydrocarbons in the oil industry. However, the API 610 standard is very traditional, and other industries may use API pumps to ensure a robust design.

Working of API Pump

 The API pumps are specially made to process hydrocarbons at very high temperature and pressure that can ignite even if they accidentally leak. Therefore, the pump body has a high-quality design and manufacturing material to stop the leakage of hydrocarbons.

 In addition, the significance of the failure of this pump can mean high production losses for the owner. In simple words, the API pump is planned very conservatively in terms of bearing design, allowable shaft deflection, weldments, flange design, casing thickness, and more.

API 610 doesn’t allow some specific types of pumps because these types are not manufactured conservatively enough or cannot handle the high pressures and temperatures.

This pump typically contains an explosion-proof motor and is powerful enough that it doesn’t need frequent maintenance. It always has a sealed impeller and a wear ring on the impeller. These impeller clamps or welds use to prevent slipping due to thermal expansion differences.

These pumps are planned to be supported by the centerline of the pump rather than the feet under the housing, allowing them to expand evenly around the centerline at high temperatures.

Components of API Pump

The API pump has the following major parts:

  • Casing: The casing of the API pump may have a single volute design, but in most cases, it has a double volute design to minimize thrust load around the shaft and impeller. These casings have the capability to withstand higher temperature and pressure and can handle polluting liquids in a better way.
  • Mounting Feet: API pumps are most commonly employed in high-temperature services; therefore, the mounting feet must fulfill the desired expansion. ANSI pump mounting feet extend from the bottom of the housing and fix to the baseplate. In contrast, the API centrifugal pumps install on the horizontal centerline of the housing instead of the bottom. The legs overhang from the side of the housing and are bolted to the base, which rises from the baseplate. In expansion conditions, the mounting feet apply nominal stress to the housing above and underneath the centerline of the pump.
  • Bearing housing: API pump housing should have a stronger structure. It must also support the bearing cooling medium. This is usually done by using a cooling jacket that provides more cooling water.
  • Back Cover Arrangement: In the oil, gas, and petrochemical industries, the EPA requires emissions controls. The ANSI design back cover arranges with a space between coupling surfaces of the pump housing and the frame adapter to discharge hazardous gases. However, the API design creates a tight seal with a compression seal that fits the metals together. This will help to emit the hazardous gases in a better way.

Applications of API Pumps

API pumps are used for multiple applications. They are most commonly used in pipelines, oil production machineries, oil refineries, and other hydrocarbon processing plants. They also use in some other industries that require a very strong and conservative design, like the power generation industry.


API pump has more weight than ANSI pump. Differences in the position of the housing, back cover arrangement, mounting feet bearing housing, and permit API pumps to handle the output. The API pumps have more reliability and efficiency in recommended services than the ANSI pumps.

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