All pipes and fittings used on a job must be tested. Testing is method for making the job perfect. We must see the fittings or pipes used are of the best quality as per the authority standards. Cast iron and soil pipes must also be tested at site by first filling them up with water for at least 2-3 minutes and then hammering the pipe to detect for blow holes and cracks. This should be done carefully since cast iron and soil pipes are easily breakable. But testing of those is very important and never skips this. Big contractors install testing bench for convenience.
The installation should be subjected to a smoke or air test after the installation of all traps and fixtures. Smoke generated in the testing machine is pumped at the stack bottom. Traps must be filled with water and other openings suitably plugged. Leakages are detected by sight or by smell of the smoke. Air tests can similarly be performed by hand-operated air pumps, plugging all open ends and observing the drop of pressure in a manometer.
In either way by using a air pump and manometer or smoke we should ensure the strength and tightness of the connection. On completion of the pipe installation and the plumbing fixtures, they shall be flushed periodically and simultaneously at different floor to ensure that the system is free of any is blockages and is able to carry the estimated flow. Testing the drainage system is very important. All the fittings and junctions are to be tested for any damage or leak before commissioning. All tests should be carried out systematically and in a planned manner.
The result must be recorded on a register or inspection cards for future reference. Whenever maintenance is required the results can be verified.