All cross-connections subject to backpressure or back siphonage where there is a low potential health contamination . Continuous pressure .

所有存在有害健康的污染可能性低，并且可能出现反压力或反虹吸的交叉连接的地方。持续压力。

All cross-connections subject to backpressure or back siphonage where there is a high potential health contamination . Continuous pressure .

所有存在有害健康的污染可能性高，并且可能出现反压力或反虹吸的交叉连接的地方。持续压力。