1) P,Q
and S Trap
These are classified according to
their shapes. They consists of a U – tube which retains water acting as a seal
between the foul gas and atmosphere. They are largely used for baths, sinks and
lavatories.
2) Gully
trap
This trap is provided at different
places in the drain pipes. Waste from sinks, baths, etc. enters in through back
inlet and unfoul water from the sweeping of the rooms, court yards etc. enters
from the top where a coarser screen grating is provided to check the solid
matter.
3) An
intercepting trap
It is provided in inspection
chamber outside the houses to prevent the entry of foul gases from the street
sewers to the houses through the house drain. It is provided with a cleaning
eye at top a plug.
4) Anti
– D trap
It is an improvement over P, Q and
S traps. The water-way in the anti – D trap is reduced which ensures the
removal of all refuse, while the outlet being larger prevents the pipe from
filling full and causing siphonic action.
5) Nahani
trap
It is made of cast iron and is
provided in all bath rooms for discharging waste water and providing a small
water seal. This trap is also provided with a cast iron grid at top.
