Waste Water Engineering
In case of sewer lines

Water test is carried out to check water tightness of the joints
Obstruction test is carried out with the help of smooth ball of diameter 13 mm
Test for straightness is carried out with the help of a lamp and mirror
All listed here

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Waste Water Engineering
Hydraulic mean radius is

Difference in heads between two points in circular pipes
Mean radius of sewer
Cross-sectional area/wetted perimeter
Mean of radii in a pipe line of varying cross -sections

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