2. Traps A trap is a depressed or bent sanitary fittingwhich always remains full of water (water seal).The function of a trap is to prevent the entry ofbad smelling gases into the house. Theeffectiveness depends upon the depth of waterseal, which varies from 25 to 75mm
3. Requirements of good trap:1. It should be capable of being easily cleaned.2. It should be easily fixed with the drain.3. It should be of simple construction.4. It should possess self-cleansing property.5. It should posses adequate water seal to fulfil the purpose of installation.6. It should be free from any inside projection which are likely to obstruct the passage of flow of sewage.7. The internal and external surfaces should be of smooth finish.
4. Types Of Traps: a. P-trap.b. Q-trap.c. S-trap.
5. P- trap:• As its name suggests, the p-trap vaguely resembles the letter "p" when turned on its side.• P-traps exit into thewall behind the sink
6. S- trap:• The "S" shape traps water so that odours from the sewer dont come up through the drain. A second and only slight benefit from the shape is that it can trap heavier objects, such as rings, that fall into the drain.
7. Q- trap:• This trap is used in toilet under water closet. It is almost similar to S trap and is used in upper storey other than ground floor.
8. Vent pipe:• The pipe installed for the purpose of ventilation is known as vent pipe through which foul gases escape into atmosphere.• Without a vent pipe (stack vent), as wastewater flows down your waste pipe, a partial vacuum would develop at the top of the pipe which would stop the wastewater from flowing the rest of the way down.
9. Vent pipe (fig.):
10. Rainwater pipe:• The pipe carrying only rainwater (from the roof tops) is called rain water pipe.• The advantage of rainwater pipes is: 1) Prevents accumulation of water on roof. 2) Water can be collected for harvesting, domestic purposes like washing, cleaning etc.
11. Rainwater pipe (fig.):
12. Anti- siphonage pipe:• Anti- siphonage pipe means any pipe provided in conjunction with a trap in the sanitary fitting to prevent unsealing of the trap by siphonage or back pressure.• Back- siphonage causes breaking of the water seal therefore anti-siphonage pipe is requires