Question

Which of the following is NOT an advantage of CI pipes?
1. They are of moderate cost
2. They are resistant to corrosion
3. Their jointing is easier
4. They are not fragile

Answer 1

Correct Answer - Option 4 : They are not fragile

Concept:

S. No.	Types of Pipes	Remarks
1.	Cast iron pipes (Most widely used in water supply for trunk as well as distributary mains)	Advantages:- Resistant to corrosion Longer life Moderate cost Easy to join Strong and durable Service connection can be made easily. Disadvantages:- Water carrying capacity decreases with time. Cannot be used for high pressure (generally P 700 kn/m2 When large, they are very heavy and uneconomical. They are liked to break during transportation.
2.	Steel pipe	It is frequently used for raw water trunk mains, inverted syphons or pumping mains, where pressures areas high and sizes larger. Life is generally taken around 40 years under ordinary conditions.
3.	GI pipes (Galvanised iron pipes)	Wrought iron pipes galvanized with zinc coating are known as GI pipes. GI pipes are liable to be affected by acidic and alkaline water. Carrying hot water in water supply lines. They are of moderate cost. They are resistant to corrosion. Their jointing is easier.
4.	PVC pipes (Polyvinyl chloride)	Used for plumbing waste lines. It can withstand water pressure up to 100 m.
5.	Vitrified clay pipes	Not used for pressure pipe. Extensively used for carrying sewage. These pipes are free from corrosion.
6.	Asbestos pipes	Silica and cement are converted under pressure, to a stiff material called asbestos. Advantages:- They are light and hence easy to transport. Highly resistant to corrosion. Require less joint in their layout. They are very suitable to be used as a small size distribution system. Disadvantages:- They are costly. These pipes do not have much strength end are brittle end soft.
7.	RCC (Reinforced cement concrete)	Mostly used as water mains. They are available in diameters from 200 mm to 1800 m.
8.	PSC (Pre-stressed concrete pipe)	They can be made to withstand higher pressure. Corrosion-resistant.