单词ring main
un.: 环形干线；环状主管
网络: 总环；环干线；环形主线
（电路的）环形干线:
an arrangement of cables that allows electricity to be supplied to a series of places from either of two directions
（管路的）环形主线:
an arrangement of connected pipes that allows water, steam, etc. to enter and leave a system
环状主管
环形干线
oil filter, plug cable or ignition cable, brake pad. piston ring, main begain.
机油滤，点火线圈，刹车垫，活塞环等。汽车配件。
Each floor also has a fire hydrant connected (16) to the vertical ring main.
与多个水平环形主管中的每个相连的至少一个灭火喷水器；
Research and Development of An Electromechanics Intelligent Type of Ring Main Cubicle
一体化智能环网柜系统的研制
Measurements of the dipoles for cooler-storage-ring main injection beam line
冷却储存环主环注入线二极磁铁测量
Design about girder-changing on Beijing-Qinhuangdao railway No 2 bridge under Beijing eastern-Third-Ring main road
北京东三环主路下京秦铁路2#桥换梁施工设计
Design and Application Technologies of Gas Insulated Ring Main Unit
气体绝缘环网开关柜的设计与使用技术
Research and development of intelligent ring main unit of control, measuring and protection
新型智能化环网柜测控保护终端的研究开发
Alignment and survey of magnets for cooler-storage-ring main ring
冷却储存环主环磁铁的准直测量
Application of Load Switch-fuse Combiner in Ring Main Unit
负荷开关-熔断器组合电器在环网柜的应用
Several Technical Problems of Ring Main Unit
关于环网柜的一些技术问题