... A105 3.Standard:ANSI B16.5 4.Certification:API carbon steel forged long welding neck flangesize 1/2" to 24" ... ,F321,F347,F310F44F51,A276 S31803, A182, F43,Etc)Alloy steel(ASTM A694 F42,F46,F52,F56,F60,F65,F70, A182 ... ,ISO 14001 Environment Mangement System Certificate,OHSAS18001 Occupational Health & Safety Mangement System Certificate, acquired the license for manufacturing special pressure ...