API 608 Vs API 6D: Valve Standard

API standards control the quality and safety of a wide range of industrial equipment. In the field of industrial valves, API 608 and API 6D are two different valve standards, both related to ball valves. Each standard is applicable to different applications in the oil and gas industry.

API 608

Design Features: This standard includes requirements for floating ball valve and trunnion ball valve designs. It emphasises features such as full bore, single reduction and double reduction options.

Inspection and Testing: API 608 requires inspection and pressure testing in accordance with API 598, with additional requirements to ensure compliance with ASME B16.34.

Primary Uses: These valves are typically used in process service handling flammable or hazardous materials that require high durability and performance at varying temperatures and pressures.

API 6D

Size and Pressure Range: API 6D is available for larger valve sizes ranging from 2 in. to 60 in. (DN 50 to DN 1500) and higher pressure ratings, from 150 to 2500.

Additional features: In addition to opening or closing media, API 6D valves typically have features such as evacuation, overpressure relief, greasing, and in-line leak detection.

Inspection and testing: The standard imposes more stringent inspection and testing requirements than API 608, with longer pressure durations and more complex operating procedures.

API 608 is suitable for medium pressure and temperature process applications, while API 6D is suitable for high pressure and high temperature long distance pipeline transport.

In terms of materials, API 608 emphasises the durability and corrosion resistance of valves for a wide range of materials and connections, while API 6D requires more stringent design and manufacturing standards for high pressure and high temperature operating conditions.

API 608 is designed for metal ball valves used in petroleum, petrochemical and industrial applications. It covers flanged, threaded and weld end ball valves.

API 6D is broader in scope, covering the design, manufacture and testing of pipeline valves, including ball, gate, plug and check valves. It is specifically tailored for long distance pipeline transport in the oil and gas industry.

Application focus: API 608 is more suited to industrial and process applications, whereas API 6D is designed for pipeline systems, especially for long-distance transport.

Valve types and sizes: API 608 focuses on ball valves up to NPS 24, while API 6D covers a wider range of valve types and larger sizes up to NPS 60.

Testing rigour: API 6D has more stringent testing and inspection protocols than API 608, reflecting its use in critical piping systems.

In summary, the choice between API 608 and API 6D depends on the specific requirements of the project, including the type of application, valve size and pressure rating. API 608 is ideal for process pipelines, while api 6D is essential for pipeline applications that require a robust and comprehensive valve solution.