A Double Check Detector Assembly shall be installed on fire protection systems when connected to a potable water supply. 当消防系统连接到饮用水供应系统时，应该安装一个双止回阀总成。
All public water supply systems in the affected districts have been chlorinated by the provincial authorities. 疫区的所有公用水供应系统已由省当局用氯进行消毒。
