In this vary article, first of all, we are going to throw light on the various shapes of sewer along with their advantages.This, also referred as Types of Sewer. So proceeding with the shapes of sewer, generally circular cross sectional is mostly used among sewer.

Read more about – Joints in Sewers.

Sewer of circular cross section has following advantages –

• Easily manufactured
• Gives the maximum are for given perimeter
• Also gives the greatest H.M.D. while running full / half-full
• Most efficient cross section at all flow conditions
• Most economical section since it utilizes minimum quantity of material
• Due to uniform curvature, it offers less opportunities for deposits

1. Circular Shaped Sewer –

Other than circular, we have non-circular shapes of sewer as following

1. Standard egg shaped / Ovoid section
2. New ovoid section
3. Horse shoe section
4. Parabolic section
5. Semi-elliptic section
6. Semi-circular section
7. U-shaped section
8. Basket handle section
9. Rectangular section

All of the above shapes, except for the the ovoid and rectangular section, however have become practically obsolete. Because there is a lot of difficulty in their construction and non-availability of factory made section of these shapes.

2. Standard Ovoid Section –

3. New Ovoid Section –

However, ovoid shaped sewers are still in use as combined sewers. In combined system, the discharge is thus subject to great variation. In rainy season, the sewers are heavily load while in summer only 5% to 10%. Hence the circular sewer, if provided for combined system, will run with very low depths. In such circumstances, however ovoid shaped sewers are more suitable. Its main advantage is that it gives slightly higher velocity during low flow than a circular sewer of the same capacity.

4. Parabolic Section –

5. Horse shoe section –

6. Semi-elliptic section –

7. Semi-circular section –

8. U-shaped section and Basket handle section

9. Rectangular section

Rectangular sections are mainly used as independent covered storm water surface drains rather than as sewers.