Welding Neck Flanges as following standards are all available:

ANSI B16.5 Class 150LB
GOST 12820-80 PN6/PN10/PN16PN25
EN1092-1 PN10/PN16/PN25
JIS B2220-1984 JIS5kg/JIS10kg/JIS F7805 1kg
DIN2573,2576,2502,2503,2566,2527,2633
BS4504 PN10/PN16