What is the difference between ASME vs API?

The difference between ASME vs API is that ASME standards hold more weight than API standards. That is, adherence to ASME standards is required for CRN registration. On the other hand, API specifications are only recommended practices. The ASME, or the American Society of Mechanical Engineers, provides codes that govern the safety of mechanical equipment. These codes are meant to provide overarching specifications for mechanical engineering applications. The API, or the American Petroleum Institute, on the other hand, produces recommended guidelines. In most cases, these standards are simply intended to encourage safety. Most commonly, these guidelines are directed at offshore structures that are used by oil and gas companies.