... :2000,NK,BV DIN 2533 flangesize 1/2" to 24" ASME B16.524"to 80" ASME B16.47Type WNF, SO, SWF, BL ... , F43, A276 S32750,A705 631,632,A961, A484,Alloy steel(ASTM A694 F42,F46,F52,F56,F60,F65,F70, A182 F12 ... China National Petroleum Corporation.We are also qualified the standard material supplier of China National Offshore Oil Corporation and China Petroleum ...