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The American Petroleum Institute (API) specifies technical standards for industrial components used in the discovery, extraction and processing of oil and natural gas. API Standard 682 is the institute’s protocol for assessing and assuring the reliability of shaft seals for centrifugal and rotary pumps. These seals from Stein are certified to API Standard 682.


Stein Seal has designed, manufactured and tested these mechanical seals to API Standard 682 protocols. In general, these are balanced seals with cartridge construction. They are classified by type, category, arrangement and configuration. Our API seals are engineered and tested to ensure thousands of hours of continuous operation without requiring replacement.


Seal designs are fully compliant with API Standard 682 design guidelines and test protocols.

Precise control of seal face tolerances delivers superior performance, including low leakage, reduced heat generation and longer seal life.

Modular cartridge design facilitates quick installation and precise shaft alignment.

Seals fit in a majority of popular pump seal housings.

For extended operating range, seals are pressure balanced, including pressure reversals up to 40 psi (2.75 bar).

High-performance premium grades of carbon and carbide faces are used in all designs.

Seals are available for shaft sizes ranging from 1 inch (25mm) to 5 inches (127mm) in .125 inch (3mm) increments.

Seal sizes over 5 inches (127 mm) are designed and supplied as Custom Engineered Seals to meet customer requirements.


A seal piping plan is designed, manufactured and supplied to improve the environment around the mechanical seal. and therefore, increase the performance and reliability of the seal. Piping plans range from very simple systems, such as fluid recirculation into the seal chamber, to complex systems, which provide pressurization, cooling and circulation for support fluids and gases. Stein piping plans and accompanying instrumentation specifications are designed to comply with API Standard 682 guidelines. Major piping plans supplied by Stein Seal are Plan-21, Plan-23, Plan-32, Plan-52, Plan-53A, Plan-53B and Plan-53C.

Several factors play a role when choosing mechanical seals and support systems. The product type, materials used and operational conditions all contribute to and affect the seal. Whether liquid or gas, temperature extremes, abrasives or volatile environments, Stein Seal Industrial has the engineering expertise and technical support to develop the best sealing solutions.

Our API 682 seal design features, manufacturing capabilities and test facilities are inspected and certified by a third-party international certification organization.