API and ISO Standards for Large Bore Butterfly Valves Compliance Large bore butterfly valves are critical components in industrial applications, particularly in oil and gas, water treatment, and chemical processing. Compliance with international standards such as those set by the American Petroleum Institute (API) and the International Organization for Standardization (ISO) ensures reliability, safety, and performance. Below is an overview of key API and ISO standards applicable to large bore butterfly valves. API Standards for Butterfly Valves 1. API 609 – Butterfly Valves: Double Flanged, Lug- and Wafer-Type - This standard covers design, materials, pressure-temperature ratings, and testing for butterfly valves used in hydrocarbon and other industrial services. - It specifies requirements for leakage rates, seat materials, and operational torque. - Large bore valves (typically above 24 inches) must comply with additional structural integrity and pressure testing criteria. 2. API 598 – Valve Inspection and Testing - Defines testing procedures for valve leakage, shell strength, and seat tightness. - Large bore butterfly valves must undergo hydrostatic and pneumatic tests to verify performance under high-pressure conditions. 3. API 6D – Pipeline Valves - While primarily for ball and gate valves, API 6D includes guidelines for large-diameter butterfly valves used in pipeline applications. - Covers fire-safe design, fugitive emissions, and extended service life requirements. ISO Standards for Butterfly Valves 1. ISO 10631 – Industrial Butterfly Valves - Specifies general requirements for butterfly valves, including dimensions, materials, and pressure ratings. - Large bore valves must meet additional criteria for structural rigidity and flow control efficiency. 2. ISO 5752 – Flanged Butterfly Valves - Defines flange dimensions and face-to-face measurements for compatibility with piping systems. - Ensures interchangeability between manufacturers. 3. ISO 5211 – Industrial Valves – Part-turn Actuator Attachments - Standardizes mounting interfaces for actuators on large bore valves, ensuring compatibility with automated control systems. 4. ISO 15848-1 – Fugitive Emissions Testing - Critical for large bore valves in hazardous environments, this standard evaluates sealing performance to minimize leakage of volatile compounds. Key Compliance Considerations - Material Selection: Valves must use corrosion-resistant materials (e.g., stainless steel, duplex steel) per API and ISO guidelines. - Pressure-Temperature Ratings: Compliance ensures valves withstand operational extremes without failure. - Testing & Certification: Third-party validation (e.g., API Monogram, ISO 9001) confirms adherence to standards. Conclusion Adherence to API and ISO standards ensures large bore butterfly valves meet stringent safety, durability, and performance requirements. Engineers and procurement teams must verify compliance with relevant standards to ensure optimal valve selection for critical applications.