... DN15-DN2500. ASTM a266 gr.4 flangeThe specification is as follows:1-American Standard:ANSI B 16.5, ASTM, ASA, ... , WNRN, SORF, BLRF, THRF, SWRF, LJRF, 2-German Standard:DIN2573, DIN2572, DIN2576, DIN2631, DIN2632, DIN2633, DIN2502, DIN2543, ... , 20K, 30K, SDPFF, SOHFF, BLFF etc.5-Other standard:UNI2276, 2277, 2278, 6084, 6089, 6090, 2544, 2282 ... or pallets for vessel transportation ASTM a266 gr.4 flange