API (American Petroleum Institute) and ASME (American Society of Mechanical Engineers) are two different organizations that develop standards for pressure safety valves (PSVs) and other equipment used in various industries. Here are the key differences between API and ASME pressure safety valves:

1. Scope and Application:

   • API Standards: API standards are primarily focused on the oil and gas industry, including exploration, production, refining, and transportation. API standards for pressure safety valves are often used in upstream and downstream oil and gas operations.
   • ASME Standards: ASME standards cover a broader range of industries, including power generation, chemical processing, manufacturing, and more. ASME pressure safety valve standards are applicable to a wide range of industrial applications beyond oil and gas.

2. Standards Development:

   • API Standards: API standards related to pressure safety valves are developed by committees within the American Petroleum Institute, consisting of industry experts, engineers, and other stakeholders from the oil and gas sector.
   • ASME Standards: ASME standards, including those for pressure safety valves, are developed by committees within the American Society of Mechanical Engineers, comprising professionals from various industries, academia, and government agencies.

3. Specific Standards:

   • API Standards: API Standard 526 covers pressure relief valves and is widely used in the oil and gas industry. This standard specifies requirements for design, materials, testing, and certification of pressure relief valves for various service conditions encountered in oil and gas production and processing.
   • ASME Standards: ASME Boiler and Pressure Vessel Code (BPVC) Section VIII, Division 1, provides requirements for pressure relief devices, including safety valves, used in a variety of industries. ASME BPVC Section I also includes requirements for pressure relief valves used specifically in power boilers.

4. Design and Certification:

   • API Standards: API standards typically focus on specific industry requirements and operating conditions encountered in oil and gas applications. API-certified pressure safety valves are designed and certified to meet the performance and reliability standards specified in API standards.
   • ASME Standards: ASME standards provide a broader framework for the design, construction, and certification of pressure safety valves used in various industries. ASME-certified pressure safety valves are designed and certified to meet the requirements specified in ASME BPVC sections applicable to their specific application.

While both API and ASME pressure safety valves serve the same fundamental purpose of protecting equipment and personnel from overpressure conditions, the specific standards, design requirements, and application focus may vary between the two organizations based on industry needs and regulatory considerations. It's essential to select pressure safety valves that comply with the appropriate standards and are suitable for the specific operating conditions and requirements of the application.