two-pipe system双管系统;双管供暖系统

two-pipe heating system双管采暖系统;双管供暖系统

two-pipe water system两管制水系统

zoned two-pipe system分区两管制

two-pipe heating systems双管供暖系统

two-pipe distribution system双管配热系统

zoning two-pipe water system分区两管制水系统

down-feed two-pipe执行机构

downfeed two-pipe household system上分双管式户内系统