Home / Standards / GB 12380.1-90 GB 12380.1-90 PN1.0MPa raised face integral ductile iron pipe flanges PN1.0MPa凸面整体球 墨铸铁管法兰 Standard Type GB ICS N/A CCS N/A Status N/A Issue Date N/A Implementation N/A Responsible Dept N/A Drafting Unit N/A