TUTORIALS
Layout and Design of Sewer Pipe
Take into consideration that sewer pipe could have section in various shapes.
Circular sewer pipe has circular section.
Rectangular sewer pipe has rectangular section.
Elliptical sewer pipe has elliptical section.
Egg shaped sewer pipe has section and shape like egg.
Basket handle sewer pipe has section and shape like basket handle.
Horse shoe sewer pipe has section like horse shoe.
These are basically the types of sewer pipes, as per the shapes and sections
Illustration – It’s requested to design a circular sewer pipe with average discharge equal to 40 litres/second. Also, sewage velocity is 1.5 m/sec.
Design: Find out diameter of pipe.
Maximum flow = Average discharge x 2 or 3 [The average flow is multiplied with multiplying factor (2 or 3) in order to convert average discharge into maximum discharge]
Maximum flow = 40 x 3 = 120 litres/second
Converting litres into m3
Maximum flow = 0.12 m3/second
Maximum flow = 0.12 cumec
With the flow, the specified sewer pipe will flow up to 2/3 and it is required to design the sewer pipe for full flow.
Full flow = 0.12 x 1.5 = 0.18 cumec
Discharge (Q) = Cross-section area (A) x Velocity (V)
A = Q/V
A = 0.18/1.5 = 0.12 m2
Circle area = πD2/4
0.12 = πD2/4
(0.12 x 4)/π = (πD2/4 x 4)/π
D2 = 0.1527887454
D = 0.39088 m or 40 cm
To get more clear idea, go through the following video tutorial.
Lecturer: Engineer Boy
