cartridge mechanical seals ANIS

What’s the Difference between ANSI Pumps and API Pumps?

ANSI and API are two types of process pump styles. Users are often confused when differentiating between them. As a result, they may end up buying a less expensive ANSI pump though an application requires API. Moreover, a user may opt for the more expensive API pump even if an ANSI pump could handle the job more effectively.


These single-stage, horizontal, end suction pumps are designed according to the dimensional standards of the American National Standards Institute. They have become a preferred style for less aggressive services such as chemical processes and water applications. The standard guides the dimensional interchangeability of pumps.

API Pumps

API pumps are manufactured according to the American Petroleum Institute Standard. They’re the most suitable option for oil refinery industry applications as they can handle high pressure and temperature applications that are more aggressive. 

Applications and Uses of ANSI and API Pumps

ANSI pumps transfer low viscosity fluids like alcohols and water and moves them with or without solids. They’re made from hard alloys and materials to operate efficiently in corrosive and demanding environments. They have been used in the chemical industry, pulp and paper textiles, food processing, and general manufacturing for several years.

On the other hand, API pumps are a better option for aggressive applications such as the oil refinery industry. They feature bearing houses, casings, back cover arrangements, and mounting feet to achieve maximum reliability and efficiency in oil refinery applications. These components also help control fluids as well as emissions.

Benefits of ANSI And API Pumps

ANSI pumps provide dimensional interchangeability and provide the end-user with more options. These users can easily switch pumps without reconfiguring the motor, bedplate, piping location, volute, or impeller. ANSI pumps and their parts are easily available in the market.  

API pumps are designed to resist high pressures and temperatures and can easily handle fluids causing environmental damage. Moreover, they’re built to control emissions according to the EPA demands.

Cartridge seal

At Robco of America, we provide mechanical sealing solutions and seal repair services for ANSI and API pumps at reasonable prices.

We also offer custom-designed seals and custom engineered parts to fulfill the unique needs of industrial applications.

To learn more, get in touch with us today through our website www.robcomechanicalseals.com, or email us at sales@robcoamerica.com.

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