nonreturn valve通风〕止回阀;单向阀;止回阀
nonreturn recording[计] 单向记录
nonreturn handle不返手柄
nonreturn flap止回瓣
nonreturn trap不可复汽阱
Nonreturn results情期一次受胎结果
nonreturn floor单向流
nonreturn finger单向安全销装置
nonreturn policy不返回政策
ADJ（形容词） denoting a mechanism that permits flow in a pipe, tunnel, etc, in one direction only (机械装置)非回流式的
a nonreturn valve