1)the siphonage:-

Due to siphonage action (due to pressure) the water seal of the trops gets broked up. It is called as siphonage. It happens when the water is sudenly discharged from any fixture on the upper floor.

2)Anti-siphonage:-

To provide protection and to remove difficult a separate pipe to provided having a smaller diameter, it is known as anti-siphonage.

3)The soil pipe:-

The pipe is used to carry out the discharges from the water closets and from the urinals. It must be made of good quality metal and should be water tight.

4)Vent pipe:-

The pipe is to provide proper ventilation. The pipe must be open at both the ends i.e. at the top also at the bottom.