Before acceptance by the town, a hydrostatic pressure test shall be successfully performed on all new force mains as follows.
(A) The test shall include all force mains from the point of beginning or the lift station to the point of termination. The test shall be performed after the piping has been accepted as being ready for testing. Any concrete thrust blocks shall have been in place for a period of at least ten days prior to the test. The test shall be performed in the presence of the town’s representative.
(B) Water for testing must be furnished by the contractor. The contractor shall furnish all necessary equipment, piping, pumps, fittings, gauges and operating personnel to properly conduct the test.
(C) The system shall be subjected to a hydrostatic test pressure at 100 psi or 150% of the operating pressure, whichever is greater.
(D) The test procedure shall be as follows:
(1) The system shall be slowly filled with water. Air shall be expelled from the pipe through air relief valves. If additional air vents are needed to ensure that all air is expelled, then the contractor shall temporarily install corporation cocks at the appropriate points. All air shall be expelled from the force main prior to applying the test pressure.
(2) After the test pressure is first applied, a visual inspection of the force main shall be made for leaks. All visible leaks shall be stopped by repairing or replacing defective or damaged pipe, fittings or valves prior to starting the official pressure test.
(3) After all visible leaks are stopped, the official test shall be conducted for a period of at least two hours. During the test, the specified test pressure shall not vary more than five psi.
(4) (a) Pumps shall be equipped with a receiving water receptacle, and the water entering the pipeline to make up leakage shall be carefully measured and recorded. Pumping equipment shall include suitably-calibrated pressure gauges. Leakage is defined as the volume of water which must be added to the pipeline to maintain a pressure within 5 psi of the specified test pressure.
(b) If the amount of make-up water entering the pipeline is less than or equal to the allowable leakage as calculated by the following formula, then the pipeline shall be accepted as having passed the leakage test satisfactorily:
L = SD (P)½
133,200
133,200
Where: L = allowable leakage, gallons per hour
S = length of pipeline tested, feet
D = nominal diameter of pipe, inches
P = average test pressure during test, pounds per square inch gauge
(c) All visible leaks shall be stopped by appropriate repairs or by the replacement of defective or damaged materials regardless of the outcome of the test.
(E) Should the line fail the test, then the pressure shall be maintained while a thorough search is made of all possible locations of leakage or other causes of pressure drop. When all such conditions are corrected, the pipeline shall be given another official test, and this procedure shall be repeated until satisfactory results are obtained.
(F) All leaks developing after the line has been tested which are made evident by a showing of water on the ground surface shall be repaired to the satisfaction of the town regardless of the results of the official test.
(Ord. 2010-3, passed 10-6-2010)