Specifications Part 1 - Water Supply, Sewerage and Tube Well Works

11.7.7 The joint with cast iron or concrete pipes shall be made with cement joints.11.8 Testing:11.8.1 Each section of sewer shall be tested for water tightness preferably betweenmanholes.11.8.2 Before commencing the hydraulic test the pipelines shall be filled with water forabout a week before commencing the application of pressure to allow for theabsorption by pipe wall.11.8.3 The sewers are tested by plugging the upper end with a provision for an air outlet pipe with stopcock. The water is filled through a funnel connected at thelower end provided with a plug. After the air has expelled through the air out let,the stop cock is closed and water level in the funnel is noted after 30 minutesand gravity of water required to restore the original water level is determined.The pipe line under pressure is then inspected while the funnel is still inposition. There shall be no any leaks in the pipe or joints (small sweating on thepipe surface is permitted).11.8.4 Any sewer or part there of that does not meet the test shall be emptied andrepaired or re-laid as required and tested again..11.8.5 The leakage of quantity of water to be supplied to maintain the test pressureduring the period of 10 minutes shall not exceed 0.2 liters/mm dia. of pipe perkilometer length per day.11.8.6 It should be done as per clause 7.1.5 of CPHEEO manual on sewerage andsewage treatment.11.9 Refilling:11.9.1 No trench shall be filled in unless the sewer stretches have been tested andapproved for water tightness of joints. However partial filling may be donekeeping the joints open to avoid disturbance. Soft material screened free fromstones or hard substances shall first be used and hand pressured under andaround the pipes to half their height.11.9.2 Similarly soft material shall be put up to a height of 30cm above top of pipe andthen this will be moistened with water and well rammed. The reminder of thetrench can be filled with hard material, in stages, each not exceeding 60 cm. Ateach stage the filling shall be well rammed, consolidated and completelysaturated with water and then only further filling shall be continued. It should bedone as per procedure given in clause 7.1.9 of CPHEEO manual on sewerageand sewage treatment.11.10 Measurement:11.10.1 The mode of payment shall be as per the running meter of the pipes provided,laid, lowered and jointed. Retention money for testing to be kept at 10% ofUrban Administration & Development Department Page 134