标记示例:How to order 公称压力为1.0MPa,公称通径为50mm,按GB569法兰连接尺寸和密封面的船用法兰直通消火栓: 消火栓 A10050 GB/T2032-93 For marine flanged fire hydrants of PN1.0MPa,DN50mm type A and the flange dimensi* in acco*ith GB569 Fire hydrants A10050 GB/T2032-93 工作压力为3.0MPa,公称通径为50mm,按GB569法兰连接尺寸和密封面的船用法兰直通消火栓: 消火栓 A30050 GB/T2032-93 For marine flanged fire hydrants of P3.0MPa,DN50mm type A and the flange dimensi* in acco*ith GB569 Fire hydrants A30050 GB/T2032-93