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In recent decades, the number of seal-less pump installations in the United States has been steadily increasing. Although seal-less pumps have existed for a long time and have been more widely used in Europe, magnetic drive and canned motor pumping technologies have seen more application in chemical processes and the oil and gas industries. Among the api pumps types, API 610 and API 685 are both standards published by the American Petroleum Institute (API), aimed at regulating the design, performance, and application of pumps in the petroleum and chemical industries. However, there are some significant differences between the two in terms of applicable fields and technical requirements.
API 610: This standard is mainly applicable to process pumps in the oil and gas industry, especially for pumping applications involving high temperatures, high pressures, and corrosive fluids. API 610 covers a wide range of liquid pumping needs, including crude oil processing, natural gas processing, petroleum refining, and the chemical industry. It imposes stringent requirements on pump design, performance, testing, and manufacturing.
API 685: Similar to api610, API 685 also applies to pumps in the petroleum and chemical processes, but it focuses on seal-less pumps (i.e., magnetic drive pumps or canned motor pumps). The design standards of API 685 are specifically tailored for seal-less centrifugal pumps used in chemical and heavy chemical applications, especially applicable for scenarios with discharge pressures above 275 psig (1900 kPa) and pumping temperatures above 300 °F (150°C). Therefore, the application scope of API 685 is mainly limited to fields with extremely high requirements for leak control, such as chemical plants and refineries.
API 610: API 610 mainly focuses on conventional types of pumps that use mechanical seals or other traditional sealing technologies. While API610 allows the use of seal-less pumps in some applications, its primary design revolves around pump systems with mechanical seals. The design of these pumps must consider the lifespan, reliability, and replacement frequency of the seals to adapt to high-pressure and high-temperature conditions.
API 685: api 685 focuses on seal-less pumps, emphasizing the elimination of mechanical seals through technologies like magnetic drive or canned motor. Since seal-less pumps do not have traditional mechanical sealing components, they have clear advantages in leak prevention, contamination prevention, and reduced maintenance. API 685 is particularly suitable for applications that need to completely prevent medium leakage, such as chemical processing or scenarios involving hazardous and toxic substances.
API 610: API610 pumps are widely used for pumping a variety of liquids, including petroleum, natural gas, acidic gases, and corrosive fluids. The standard has detailed requirements for different types of fluids to ensure the safety and long-term operational stability of the pumps.
API 685: API 685 focuses on applications that require high safety and low leakage, especially for corrosive, flammable, and highly toxic liquids or gases in the chemical industry. Seal-less pumps can effectively prevent leaks of these hazardous fluids, making them more advantageous when handling such media.
API 610 and API 685 both provide technical standards for petroleum, natural gas, and chemical process pumps, but their respective application focus differs. API610 is applicable to various types of pumps, including traditional pumps using mechanical seals, while API 685 is specifically designed for seal-less pumps, emphasizing high safety and low maintenance advantages in the chemical and heavy chemical fields. With the increasing demand for leak control and maintenance reduction, API 685, as the standard for seal-less pumps, is gaining more favor in the oil, chemical, and natural gas industries.
