API 607 and API 608 are two vital valve standards commonly used in industrial applications, especially in sectors like oil and gas, chemical, and petrochemical. Though both are important, they serve different purposes and apply to distinct types of valves. In this article, we will compare API 607 vs API 608, exploring their scope, testing requirements, and ideal applications. Whether you are an industrial engineer, procurement specialist, maintenance technician, or a student, this guide will help you understand when and why to apply each standard in your projects.

 

Understanding API 607 vs API 608

API 607 Standard Overview

API 607 is a standard developed by the American Petroleum Institute (API) that outlines the requirements for fire testing of soft-seated quarter-turn valves, primarily ball valves and butterfly valves. The goal of this standard is to ensure that valves used in hazardous environments, such as oil and gas processing facilities, can maintain their functionality and containment capabilities during and after exposure to a fire. Fire safety is a critical concern in these industries, and API 607 helps ensure that valves meet stringent safety standards to prevent catastrophic failure in the event of a fire.

The testing procedures involve subjecting valves to fire conditions to verify their ability to contain fluid and operate effectively. Valves that pass the API 607 fire test demonstrate resilience under extreme heat and can help protect personnel and equipment in emergency situations.

Key aspects of API 607

Source: IndiaMart

Scope and Applicability

API 607 applies to soft-seated, quarter-turn valves, including ball, plug, and butterfly valves. These valves are commonly used in industries such as oil and gas, petrochemical, and chemical processing, where fire safety is paramount.

Fire Test Procedure

The standard specifies a rigorous fire test procedure to evaluate a valve’s performance under fire conditions. The valve is exposed to a flame temperature of approximately 1400°F (760°C) for a duration of 30 minutes. During this period, the valve is pressurized with a test medium, typically water or air, to simulate operational conditions. The test assesses the valve’s ability to prevent internal leakage through the seat and stem during and after fire exposure.

Acceptance Criteria

To pass the API 607 fire test, valves must demonstrate minimal internal leakage during and after the fire exposure. The standard defines specific permissible leakage rates, ensuring that the valve can effectively contain fluids under fire conditions. Additionally, the valve must remain operable after the fire test, indicating that it can still function as intended in emergency situations.

Design and Construction Considerations

Valves designed to meet API 607 standards often incorporate features to enhance fire safety. These may include the use of fire-resistant materials, secondary metal-to-metal seating to provide a seal if the soft seat is damaged, and stem seals designed to prevent leakage during thermal expansion. Such design considerations are crucial for maintaining valve integrity under extreme conditions.

Importance in Industry

Compliance with API 607 is essential for ensuring the reliability and safety of valves in fire-prone environments. By adhering to this standard, manufacturers and operators can mitigate the risk of catastrophic failures, protect personnel and equipment, and maintain operational continuity during fire incidents. The standard serves as a benchmark for valve performance, guiding the design, testing, and selection of valves in critical applications.

 

In summary, API 607 provides a comprehensive framework for evaluating the fire safety of soft-seated, quarter-turn valves. Its stringent testing procedures and acceptance criteria ensure that valves can withstand fire exposure, maintain sealing integrity, and remain operable, thereby safeguarding industrial processes and personnel.

 

The follow Youtube video demonstrates the actual testing process for API 607, showcasing the fire safety procedures and performance evaluation of valves under extreme heat conditions.

Source:Union Tech

 

API 608 Standard Overview

API 608 is also an American Petroleum Institute standard that specifies the requirements for metal ball valves used in general process piping systems. The focus of API 608 is on floating and trunnion-mounted ball valves used in upstream, midstream, and downstream applications. Unlike API 607, which focuses on fire testing, API 608 primarily addresses valve design, pressure-temperature ratings, materials, and construction.

API 608 valves are typically used for controlling the flow of various fluids in non-fire-critical environments. These valves are recognized for their reliability, low torque operation, and ability to provide a tight shut-off in process piping systems. They are widely used in industries such as chemical processing, refining, and other general industrial applications.

 

Key aspects of API 608

Scope and Applicability

API 608 applies to metal ball valves with the following end connections and sizes:

• Flanged Ends: Sizes ranging from DN 15 to DN 600 (NPS ½ to NPS 24).
• Butt-Welding Ends: Sizes from DN 15 to DN 600 (NPS ½ to NPS 24).
• Socket-Welding Ends: Sizes from DN 8 to DN 50 (NPS ¼ to NPS 2).
• Threaded Ends: Sizes from DN 8 to DN 50 (NPS ¼ to NPS 2).

 

The standard covers pressure classes 150, 300, and 600 for flanged ends, and classes 150, 300, 600, and 800 for butt-welding, socket-welding, and threaded ends.

Design and Construction

API 608 outlines specific design requirements to ensure valve integrity and performance:

• Bore Sizes: The standard defines full bore, single reduced bore, and double reduced bore configurations to accommodate various flow requirements.
• Valve Types: It includes provisions for both floating (seat-supported) and trunnion-mounted ball valve designs, ensuring versatility in application.
• Materials: The standard specifies materials suitable for different service conditions, emphasizing corrosion resistance and mechanical strength.

Pressure-Temperature Ratings

The standard provides guidelines for pressure-temperature ratings, ensuring that valves can withstand specified pressures at various temperatures. These ratings are crucial for maintaining safety and functionality under operational stresses.

Testing and Inspection

API 608 mandates rigorous testing and inspection procedures:

• Hydrostatic Testing: Valves must undergo hydrostatic shell and seat tests to verify pressure containment capabilities.
• Fire Testing: Compliance with API 607 fire test requirements is necessary to ensure valve performance during fire exposure.
• Fugitive Emissions Testing: The standard references API 641 for type testing of quarter-turn valves for fugitive emissions, addressing environmental and safety concerns.

Marking and Documentation

Valves conforming to API 608 must be appropriately marked with relevant information, including pressure class, size, and material. Comprehensive documentation, such as test reports and material certifications, is required to verify compliance and traceability.

Industry Significance

Adherence to API 608 ensures that metal ball valves meet high standards of safety, reliability, and performance. This compliance is vital in industries where valve failure can lead to significant safety hazards and operational disruptions.

 

In summary, API 608 provides a comprehensive framework for the design, testing, and application of metal ball valves in critical industrial sectors. Its stringent requirements ensure that valves operate safely and effectively under demanding conditions, thereby safeguarding both personnel and equipment.

 

Key Differences Between API 607 and API 608

Feature	API 607	API 608
Applicable Valve Type	Soft-seated, quarter-turn valves (e.g., ball, plug, butterfly valves)	Metal ball valves (both soft and metal-seated variants)
Test Temperature	Exceeds 650°C	Exceeds 650°C
Sealing Test	Conducted post-fire exposure to assess internal leakage	Conducted post-fire exposure, evaluating both internal and external leakage
Leakage Standard	Based on ISO 5208; focuses on internal leakage criteria	Based on ISO 5208; imposes stricter limits, particularly concerning external leakage
Test Medium	Water or gas	Water or gas
Main Test Purpose	Verify fire resistance of soft-seated valves, ensuring prevention of leakage during and after fire	Assess fire resistance of metal-seated ball valves, focusing on maintaining sealing integrity
Applicable Industries	Oil and gas, petrochemical, chemical processing, and other sectors where fire safety is critical	High-risk industries like oil and gas, emphasizing durability and fire-resistant properties

 

Industry Applications

API 607:

Source:monfordgroup

API 607 is a fire-test standard designed for soft-seated quarter-turn valves, such as ball and plug valves. It ensures that valves can maintain their sealing integrity when exposed to fire, minimizing the risk of hazardous leaks. This standard is particularly vital in industries where fire hazards are prevalent, such as:

• Petrochemical Industry: In refining processes, valves must withstand high temperatures and pressures. API 607-compliant valves are essential for ensuring safety during operations involving flammable materials.

• Liquefied Natural Gas (LNG) Facilities: Handling LNG involves managing extremely low temperatures and potential fire risks. Valves adhering to API 607 standards are crucial for maintaining safety and operational integrity in these environments.

API 608:

Source: Stantec

API 608 specifies the requirements for metal-seated ball valves used in general process piping systems. While it includes fire safety considerations, its broader focus on durability and performance makes it suitable for:

• Water Treatment Facilities: Valves conforming to API 608 are used for controlling the flow of water in treatment plants, ensuring efficient operation and longevity.

• Heating, Ventilation, and Air Conditioning (HVAC) Systems: These valves are employed in HVAC applications for regulating fluid flow, contributing to energy efficiency and system reliability.

• Low-Risk Fluid Systems: API 608 valves are ideal for applications involving non-flammable and non-hazardous fluids, where the primary concerns are durability and performance under standard operating conditions.

 

Certification Process Overview

Achieving compliance with API 607 and API 608 standards involves distinct procedures tailored to their specific requirements.

Source: CarbonValve

Steps for Achieving API 607 Certification

API 607 outlines the fire-test procedures for quarter-turn valves and valves equipped with nonmetallic seats. The certification process includes:

1. Documentation Submission: Manufacturers must provide detailed technical documentation, including valve designs, material specifications, and intended applications. This documentation demonstrates alignment with API 607 requirements.

2. Prototype Testing: Valves undergo rigorous fire testing, where they are exposed to controlled fire conditions to assess their performance. The valve must maintain sealing integrity during and after the fire exposure.

3. Third-Party Audits: Independent organizations conduct audits to verify that manufacturing processes and facilities meet API 607 standards. These audits may include on-site inspections and reviews of quality management systems.

4. Certification Issuance: Upon successful completion of testing and audits, manufacturers receive API 607 certification, confirming that their valves meet the specified fire safety standards.

Simplified Compliance Pathway for API 608

API 608 specifies the requirements for metal-seated ball valves used in general industrial applications. The compliance process is generally more straightforward:

1. Documentation Submission: Manufacturers provide technical documentation detailing valve designs, materials, and intended uses, ensuring alignment with API 608 standards.

2. Prototype Testing: Valves are subjected to standard performance tests, including pressure and temperature evaluations, to confirm they meet API 608 requirements.

3. Third-Party Audits: Independent audits assess manufacturing processes and facilities to ensure compliance with API 608 standards.

4. Certification Issuance: Successful completion of testing and audits results in the issuance of API 608 certification, indicating that the valves meet the necessary performance standards.

 

How to Choose Between API 607 and API 608

Selecting the appropriate valve standard is crucial for ensuring safety, performance, and compliance in industrial applications. When deciding between API 607 and API 608, consider the following factors:

1. Operational Environment

• Fire Hazards vs. Standard Conditions:
  • API 607: Designed for applications where fire safety is paramount, such as the oil and gas industry. Valves must maintain sealing integrity during and after exposure to fire conditions.
  • API 608: Suitable for general industrial applications without specific fire safety requirements. Focuses on durability and performance under standard operating conditions.

2. Regulatory Requirements

• Compliance Standards:
  • API 607: Meets fire safety standards essential for industries handling flammable materials. Compliance may be mandated by regulatory bodies in sectors like petrochemicals and offshore drilling.
  • API 608: Adheres to general industrial standards, suitable for applications where fire safety is not a primary concern.

3. Cost Implications

• Manufacturing and Testing:
  • API 607: Involves additional fire safety testing, which can increase manufacturing costs. However, this investment enhances safety and may reduce potential fire-related incidents.
  • API 608: Generally incurs lower manufacturing costs due to standard testing procedures. Suitable for applications where fire safety is not a critical concern.

 

In summary, selecting between API 607 and API 608 depends on your operational environment, regulatory requirements, and budget considerations. API 607 is ideal for fire-prone industries requiring enhanced safety measures, while API 608 suits general industrial applications without specific fire safety needs.

 

FAQs

1. Can API 608 valves replace API 607 valves in fire-safe scenarios?

API 608 valves are designed for general industrial applications and may not meet the stringent fire safety requirements of API 607. In fire-prone environments, it’s advisable to use valves specifically certified under API 607 to ensure compliance with fire safety standards.

2. Are there overlapping use cases?

Yes, both API 607 and API 608 valves are used in various industries, including chemical processing and power generation. However, API 607 valves are specifically designed to maintain sealing integrity during and after exposure to fire conditions, making them suitable for fire-prone environments.

 

Conclusion

API 607 and API 608 are both critical standards that address different aspects of valve safety and performance. Understanding the differences between these two standards will help you make informed decisions about valve selection based on the needs of your application. By choosing the right valve standard, you can ensure both safety and efficiency in your industrial operations.

If you need more information or assistance in selecting a valve that complies with API 607 or API 608 standards, feel free to reach out to us. Tanggong Valve Group is here to provide expert guidance for your specific application needs.

 

Related Article

API 600 vs API 602: A concise guide covering the key differences between API 600 and API 602 standards, helping you determine which one suits your industrial valve needs.

API 608 vs API 6D – Valve Standards: Understand the scope, differences, and best use cases for API 608 and API 6D to select the right valve for pipeline or industrial applications.