一旦决定修复现有的总水管，你接下来的想法必须集中在提供持续的家庭服务和消防上。在某些情况下，但在极少数情况下，在施工期间，可以容忍每天短时间关闭水管。在正常情况下，清洁和衬里项目几乎肯定需要大量停机，因此需要旁通管道。

Once a determination has been made to rehabilitate an existing water main, your next thoughts must be centered on supplying continuous domestic service and fire protection. In some instances, but very few, shutdown of water mains for very short periods on a daily basis can be tolerated while work is being carried out. Under normal conditions cleaning and lining projects are almost certain to require extensive shutdowns, thereby necessitating the need for bypass piping.