Hydraulic test
It is suitable for new drainage systems.
It can be carried out between two consecutive manholes/chambers.
Lower end of the drain should be plugged with an expanding rubber stopper or with a flexible pneumatic stopper.
The section of the drain under test is filled with water using a funnel, with approximately 60 cm head above the highest joint.
Highest joint should also be plugged and the funnel passed through it.
Fill the water in the drain and leave for approximately 2 hours.
Check the level in the funnel. A subsiding water level in the funnel indicates leakage in the drain section.
Leaky joint or spots can be marked by more observation.
Air test
Here, the pipeline section under test in plugged on both ends and traps are fully water sealed.
Air forced into the pipeline.
Air pressure is adjusted to maintain the water seals in the traps (i.e. 7.5 cm)
Failure of the air to maintain difference in water levels indicates leakage.
Suspected joints may then be coated with a soap solution. This helps detect the spot/leaky joint from where the air escapes.
Smoke test
It is suitable for waste systems, ventilating and soil pipes and shallow drains in porous soil.
All traps and lower ends are fully sealed.
Smoke is introduced in the drain with a special machine or smoke rockets.
Any leakage of smoke indicates the exact location of leaky joints.
