MSS SP-6-2007 管法兰以和阀门和管件端法兰接触面标准精度
MSS SP-6-2007Standard Finishes forContact Faces of Pipe Flangesand Connecting-End Flangesof Valves a
MSS SP-6-2007 管法兰以和阀门和管件端法兰接触面标准精度