Home / Standards / GB 11449.4-89 GB 11449.4-89 Waveguide Flanges — Part 4: Specification for Circular Waveguide Flanges 波导法兰盘 第4部分:圆形波导法兰盘规范 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