two-pipe heating system 双管采暖系统 ; 双管供暖系统

two pipe heating system 双管供热系统

one-and-two pipe combined heating system 单双管混合式采暖系统

two pipe drop heating system 双管上分供暖系统

two pipe upfeed heating system 双管上分供暖系统

two pipe combined heating system 单双管混合式采暖系统

one-two pipe combined heating system 双管混合采暖系统