Home / Standards / GB 12383.4-90 GB 12383.4-90 PN 2.5 MPa raised face ductile iron pipe flange cover PN2.5MPa凸面球墨铁管法兰盖 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