Not really. You could switch to ASME B&PV code instead. If pressure is low enough (2.5 PSI or less), you could use API-650 with App. M and F. App. M would probably be useful reading, regardless. And you could cobble together App. M and API-620, which wouldn't strictly meet either code.
JStephen thanks for the info. The design pressure of the tank is 5 psig so I can't use API 650 exclusively. Is it possible to design under two different API Codes?
You could use parts of two different standards to design a tank, but you couldn't accurately represent the tank as fully meeting either standard. Depending on the customer and other requirements, that may or may not be a problem.
