Discussion on Design Velocity of Sewerage Pipelines in Mountain Area

In according to the code for outdoor sewerage pipelines design,the maximum design velocity of wastewater flowing in sewers is 10 m/s for metallic pipe or 5 m/s for nonmetallic pipe.However,it has been found that there are several cases,in which the pipe velocity is in excess of the maximum design velocity and the system is running well.After investigation and survey,a discussion was made on the design code for outdoor sewerage pipelines and proposes a suggestion on increase of the maximum design velocity of outdoor sewerage pipelines.