2. -: CREATED BY :-
AALAY MEHTA 141080106011
SHIVANI PATEL 141080106021
KAVIN RAVAL 141080106026
KUNTAL SONI 141080106028
-: SUBMITTED TO :-
PROF. KINNARY RANGPARIYA
4. HOUSE DRAINAGE PLAN
Before starting the plumbing work, it is most essential first to prepare the
drainage plan.
The site plan is drawn to a suitable scale, showing onto it the position of
baths, w.c., Urinals, wash basins, and other units, along with the position of
gully traps and floor traps.
The longitudinal section of the drain is also drawn, showing distances, invert
levels, size and levels of inspection chambers and man holes, gradient of
pipes and position and level of the public sewer.
5. HOUSE DRAINAGE PLAN
The following points should be kept in mind while preparing the drainage
plan:
1. the drains should be laid in such a way so as to remove the sewage quickly
from the building. The drains should be laid at a slope that self cleansing
velocity is developed in them.
the following slopes are usually sufficient :
Diameter of pipe Gradient
100 mm 1 in 40
150 mm 1 in 60
230 mm 1 in 90
6. HOUSE DRAINAGE PLAN
2. Entire drainage system should be properly ventilated on the house side. The
ventilation pipe should be carried sufficiently high above the buildings. All the
inspection chambers should be provided with fresh air inlets.
3. All the drains should be laid in such a way so as to ensure their safety in
future.
4. The drain should be laid in such a way that in future, extension can be done
easily.
5. All soil pipes should be carried direct to the manholes without gully trap.
6. Pipes should be laid in straight lines both horizontal as well as in the vertical
directions . Any abrupt change in the direction of the flow should be avoided.
7. Where pipes intersect or where there is change in the direction of pipe .
Inspection chambers should be provided.
8. All rain water pipes should discharge over gully traps and should be
disconnected from the drains.
8. TESTING OF DRAINS AND PIPES
After laying the house drains and fittings in the pipes , their water tightness
should be ascertained by applying various tests . The drains are usually tested
in sections between successive chambers, and vertical pipes are tested in
groups having one common inspection chamber.
The following tests are usually conducted :
1. Air test
2. Coloured water test
3. Hydraulic test
4. Smell test
5. Smoke test
9. TESTING OF DRAINS AND PIPES
air test
The air test can be applied from underground and vertical pipes. The
particular section is selected and the plugs are provided at the upper and
lower ends. The air is forced in the pipe by suitable equipment such as pump.
The leaky joints are found out by applying soap solution. The escape of air
from leaky joints will form bubbles which are visible . These joints are then
repaired.
10. TESTING OF DRAINS AND PIPES
coloured water test
When coloured water is allowed to flow from one point to the other point of
the drain, it will come out through the leaky joints. Thus, the leakage can be
detected and suitable remedies may be applied.
11. TESTING OF DRAINS AND PIPES
hydraulic test
This is the most important test which is applied for the water tightness of the
underground drains . The lower end is provided with a plug and at the upper
manhole, the water is filled to a height of about 600mm to 900mm in case of
house drains. If there is no drop in water level for a period of about 10
minutes, it can be safely assumed that no joint is leaking. Otherwise from
leaky joints are detected and repaired.
12. TESTING OF DRAINS AND PIPES
smell test
This test is similar to the air test. But, in this case air is mixed with some
smelling gas which can be easily recognized. Such air is allowed to pass
through the drain. The escape of air fro leaky joints is detected by smell and
such joints are then repaired.
13. TESTING OF DRAINS AND PIPES
smoke test
This test is also similar to the air test, except that the smoke is introduced in
the drains instead of air. The test is generally applied for detecting leakage in
existing drains.