API 5000What does it refer to? 1

api5000API 6A Type 6BX 5000 PSI Weld Neck Flanges are generally used in hh pressure applications, where hot or cold temperatures exist. These steel API 6A weld neck flangesAPI 6A Type 6B 5000 PSI Weld Neck Flanges are generally used in hh pressure applications, where hot or cold temperatures exist. These steel API 6A weld neck flanges