排水管道
To prevent water damage, the valve must be properly connected to a discharge line which terminates at an adequate drain. 為了防止水的破壞,這些閥門必須與排水管道連接,以便能夠將水排到適當?shù)呐潘凇?!--www.www.sigorfond.com 中小學英語網(wǎng)-->
Drains which pass under a house must be of cast iron, the most expsive material for pipe drains. 穿過房屋下面的排水管道,必須使用鑄鐵管,這是排水管所用的最昂貴的材料。