Laserfiche WebLink
x, <br /> C . Flushing shall continue until a minimum water volume of two times the aggregate <br /> pipe volume has passed through the pipe section being cleaned. The aggregate pipe <br /> volume shall include all pipe carrying flushing water from the point of introduction <br /> to the work to the point(s) of discharge from the run being cleaned. <br /> D . For nominal pipe sizes of 6 inches and smaller, the pipe shall be flushed through a <br /> discharge extension of at least the full pipe diameter. For nominal pipe sizes greater <br /> than 6 inches, a 6 inch diameter discharge extension pipe, connected to the work with <br /> reducer(s), may be used in lieu of a full diameter blowoff. <br /> 4 <br /> E . Flushing water shall be carried beyond the trench and shall be discharged in a <br /> manner that will not cause erosion nor structural damage on or off-site, and will not <br /> cause contravention of State water quality standards in receiving surface waters . The <br /> Contractor shall provide adequate extension pipe, sedimentation basin(s) , and/or <br /> diffusion devices as necessary to prevent such damage. <br /> 4 . HYDROSTATIC LEAKAGE AND PRESSURE TESTING <br /> A. Hydrostatic pressure and leakage tests for ductile iron pipe shall conform with <br /> Section 4 of AWWA C-600 Specification with the exception that the Contractor shall <br /> furnish all gauges, meters, pressure pumps and other equipment needed to test the <br /> line . P. V . C . pipe shall be tested in accordance with the applicable sections of <br /> AWWA M23 . Upon completion of flushing, the installed pipe system shall be <br /> tested for tightness under a continuous hydrostatic gauge pressure of 25 psi and then <br /> 100 or 150 psi as applicable, ± 5 psi as applicable, determined at the lowest point in <br /> the system, for a period of 2 hours . The allowable leakage rate shall not exceed that <br /> defined in and specified by AWWA C600- 82 or AWWA M23 , <br /> Be If the work is subject to acceptance by a municipal or private utility with its own <br /> adopted test requirements more stringent than those stated herein with regard to <br /> pressure, duration, and/or allowable leakage rate, such requirements shall supersede <br /> these specifications . <br /> C . Testing shall be performed separately on each valved-off section of the installed <br /> system . Testing shall be against closed in-line valves with each valve in the system <br /> subject to the full test pressure differential for full test time at least once during the <br /> course of testing. <br /> D . Allowable leakage shall be calculated based on the pipe diameter(s) and total laid <br /> length of the run being tested, with no additional allowance for fittings , or joints . No <br /> visible leakage shall be allowed . <br /> If visible leakage is noted during the course of testing, or if allowable leakage is <br /> exceeded, such leakage shall be repaired to the satisfaction of the Engineer and the <br /> test repeated or extended for an additional period up to the full test time with suitable <br /> adjustment for previous make-up water used, at the Engineer's discretion. <br /> CAD own 1 oad\techspec-02704.doc <br />