Precautions in internal drainage
Branch pipeline should be provided with a proper slope, minimum bends and outlets with minimum joints.
Bends should have a large radius.
Fittings like tee, bend, ‘Y’ etc. should be provided with clean-out or trap window at the proper locations in the pipe network.
Embedding pipes below the masonry or floor should be avoided. At least it should be kept to the minimum required length.
All traps and fittings should be free of cracks, holes, burr etc, and must be checked before use.
All external fittings like bend, tee, ‘Y’ etc. should be easily accessible.
Use of long arm N.T. joints should be reduced and if possible, connected directly to the main stacks.
Precautions in external drainage
Inspection chambers and manholes should be spaced to facilitate the cleaning of sewer lines.
Inlets and outlets of chambers and manholes should be plugged until the completion of the sewer lines upto disposal, so as to avoid blockage/choke-up of sewer pipeline.
All sewer pipelines should be laid at the required slope, for self-cleaning by the flow.
Ensure that the gullies/channels of inspection chambers/manholes have a smooth curve, if the sewer lines intersect at right angles.
Bottom of gullies/channels should be laid in slope from inlet to outlet of chambers and be finished smooth.
All sewer pipes, traps and fittings should be free of cracks, holes, burr etc. They must be checked before use.
