API 682 - Pumps Shaft Sealing Systems

24 April 2026

Verified by Mel Sykes, Industrial Supply Chain Specialist - April 2026


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What's API 682?

API 682 is a standard issued by the American Petroleum Institute that specifies technical requirements for mechanical seals used in pumps and compressors. API 682 - Pumps Shaft Sealing Systems It sets out dimensions, materials, performance criteria, and testing procedures to ensure reliable and safe operation of sealing systems.

Why Was API 682 Developed?

API 682 was developed to address specific challenges faced in the oil and gas industry, such as dealing with high-temperature and high-pressure environments. Released in 1997, it provides a uniform set of guidelines for manufacturers and end users, reducing downtime and maintenance costs.

Which Products Does API 682 Apply To?

API 682 applies to mechanical seals used in pumps and compressors, including those found in refineries, petrochemical plants, and offshore platforms. This includes single seal systems, tandem seal systems, and back-to-back seal arrangements.

What Are the Key Technical Requirements of API 682?

Key technical requirements include dimensional tolerances for shaft diameters from 40 mm to 500 mm, material grades such as A2-70 stainless steel or EN8 carbon steel, and minimum leakage rates. The standard also specifies testing procedures like high-pressure leak tests and endurance tests.

How Do Engineers Use API 682 in Practice?

Engineers use API 682 to select appropriate seal designs based on operating conditions. For example, they will choose materials resistant to corrosion or temperature extremes, such as AISI 316L stainless steel for corrosive environments. Testing protocols outlined in the standard help verify that seals meet performance criteria.

What Are Some Specific Dimensions and Tolerances?

API 682 specifies dimensional tolerances for shaft diameters ranging from 40 mm to 500 mm, with a tolerance of ±0.1 mm. For example, a shaft diameter of 50 mm must be within 49.9 mm to 50.1 mm.

How Does API 682 Relate to Other Standards?

API 682 complements other relevant standards like ISO 14125 and ASME B73.1, which cover similar aspects of mechanical seals but may have different application scopes or testing requirements. Engineers often cross-reference these standards for a more full understanding.

What Are the Financial Implications of Adhering to API 682?

Adherence to API 682 can reduce maintenance costs by ensuring seals last longer and require fewer replacements. For instance, a study by the British Institute of Fluid Engineering and Distribution (BIAFD) found that companies saving £100,000 annually on seal failures could cut this figure in half by implementing API 682 guidelines.

How Does API 682 Impact Safety?

API 682 enhances safety by preventing leakage from seals, which can be hazardous in chemical or oil processing plants. By setting strict performance criteria and testing requirements, it minimizes the risk of leaks that could lead to environmental damage or accidents.

What Are Some Challenges When Implementing API 682?

One challenge is selecting materials that meet API 682 specifications while also being compatible with specific operating conditions. For example, seals must withstand corrosive media and high temperatures without degrading over time. Additionally, testing protocols can be costly and resource-intensive.

What Resources Are Available to Help Engineers Implement API 682?

API provides detailed guidelines and training courses on implementing API 682. Trade bodies like the British Pump Manufacturers Association (BPMA) and the British Technical Manufacturers Association (BTMA) also offer resources such as workshops, webinars, and technical papers.

What Are Some Future Trends for API 682 Compliance?

Future trends include integrating predictive maintenance tools with API 682 compliance to detect seal wear before failures occur. This approach can further reduce downtime and maintenance costs by allowing proactive replacements based on real-time data analysis.

API 682 is a critical standard for ensuring the reliability and safety of mechanical seals in pumps and compressors, particularly in harsh industrial environments. By adhering to its specifications, engineers can enhance operational efficiency while minimizing risks.

References

  1. API

Frequently Asked Questions

What does API 682 cover?

API 682 (API 682 - Pumps Shaft Sealing Systems) specifies requirements for seals-gaskets, pumps-compressors. It is issued by API and widely used in UK engineering procurement and manufacturing.

Is API 682 mandatory in the UK?

API 682 is not law, but it is referenced in most UK engineering specifications and procurement contracts. Many buyers require compliance as a condition of supply.

What does API 682 - Pumps Shaft Sealing Systems specify?

API 682 specifies technical requirements for mechanical seals used in pumps and compressors, detailing dimensions, materials like A2-70 stainless steel or EN8 carbon steel, performance criteria, and testing procedures to ensure reliable operation.

What are the different types of sealing systems covered under API 682?

The standard covers single seal systems, tandem seal systems, and back-to-back seal arrangements used in pumps and compressors in industrial settings such as refineries and offshore platforms.

How do UK engineers choose the right materials for pump seals according to API 682?

Engineers should select materials based on the specific operating conditions like temperature and pressure. API 682 - Pumps Shaft Sealing Systems recommends using grade A2-70 stainless steel or EN8 carbon steel, which meet dimensional tolerances and performance standards.

Where can UK engineers find suppliers for components that comply with API 682?

Engineers in the UK should consult industrial supply chain specialists who are familiar with API 682 to source compliant materials. Suppliers like those listed on mlc.org.uk provide products meeting the standard's requirements, ensuring reliable and safe operation of sealing systems.

What is the primary purpose of API 682 - Pumps Shaft Sealing Systems?

API 682 - Pumps Shaft Sealing Systems was developed to provide a standardized approach for mechanical seals used in pumps and compressors, ensuring reliability and safety in high-temperature and high-pressure environments.

What are the different types of sealing systems covered by API 682 - Pumps Shaft Sealing Systems?

API 682 covers various sealing system types including single seal systems, tandem seal systems, and back-to-back seal arrangements, all designed to meet specific performance criteria in industrial settings.

How do engineers choose the correct material grade for a mechanical seal according to API 682 - Pumps Shaft Sealing Systems?

Engineers should select materials based on the operating conditions such as temperature and pressure. Common choices include A2-70 stainless steel or EN8 carbon steel, adhering to the dimensional tolerances specified in API 682 for shaft diameters ranging from 40 mm to 500 mm.

Where can UK engineers find suppliers for products compliant with API 682 - Pumps Shaft Sealing Systems?

UK engineers can locate suppliers of API 682-compliant seals by consulting industrial supply chain specialists and visiting industry websites like mlc.org.uk, which lists verified manufacturers and distributors adhering to this standard.

References