Generally, there should not be any nitrite in drinking water; while it is found through monitoring that the water detained in tap-water pipe is polluted by nitrite to some extent.

经监测发现，在自来水管中滞留过的水，不同程度地存在亚硝酸盐。

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Once the water is shut off inside, go outside and open the outside taps as well. This will drain any water remaining in the pipe or in the tap, so there's nothing to freeze.

一旦关闭这只阀门切断室内水路后，立即到室外打开水龙头，排掉积存在管子里或者水龙头里的水，以确保无可结冰的物质。

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But, no matter how simplistic this design is, you will still have to solder copper pipe joints if you want to tap into your existing hot water system.

但是，这个设计无论多么简单，你总得要焊接铜管，以便接入你现有的热水供应系统。

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