What are API 6A flanges?

api5000API has specified weld necks for many 6BX flanges, and not done so for many others, but API has provided the basis for determining the dimensions of a 6BX integral flange that the manufacturer may attach to aAPI Stands for American Petroleum Institute. API Socket Weld Flanges are manufactured to provide hh strength and robustness. These flanges are made for hh heat purposes. These