procedures for wet-tapping water mains - DC Water

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2. Wet-tapping CriteriaWet-taps shall be made in accordance with the following criteria:• The tapped connection shall be at least one size smaller than the pipe beingtapped, i.e. 12-inch diameter pipe being tapped, the maximum tapping diameterwould be 10-inch diameter.• Wet-taps shall be at least 6-inch diameter and larger, no 4-inch diameter taps ortapping valves are permitted. Two (2”) inch taps will be allowed with a preapprovedtapping assembly.• Tapping sleeves shall be installed at least 4-feet from any exposed pipe joint orexisting tap.• Tapping sleeves shall be full-body ductile iron. Valves shall be as approved byDCWASA. Contractor shall submit shop drawings of the proposed sleeve andvalve to the Supervisor, Civil and Structural Section for approval prior toundertaking any work.• Wet-taps shall be made only by experienced contractors specializing in theinstallation of wet-taps. (Refer to Contractor experience and qualifications,Section 5 for requirements relative to this item.)• Wet-tap installation and testing shall be made in accordance with themanufacturer’s recommendations. The tapping saddle shall be designed for thetest pressure of the main being tapped.• Prior to undertaking any work, or ordering of materials, the Contractor shall testpit the pipe at the location of the tap and verify the outside diameter of the pipe toinsure that the correct size saddle is provided.• Contractor shall be responsible for obtaining a Public Space Permit from DDOTand complying with all requirements of this permit, including placement andmaintenance of temporary steel plating.• Contractor shall provide all required sheeting, shoring, bracing, dewatering, etc.to maintain a safe and dry excavation throughout the wet-tap installation process.3. Pipe Condition AssessmentRevised 1/25/2006 2
• In order to determine if the pipe is suitable for tapping, the DCWASA Inspectorwill arrange to have the pipe tested by DCWASA’s Corrosion Consultant.• The pipe condition assessment shall be undertaken at the same time as theContractor is undertaking the test pit operations to confirm the outside diameter ofthe pipe. To avoid delays, the Contractor shall provide DCWASA with at least 7calendar days advance notice when the test pitting operations will be undertakenso that the DCWASA Inspector can coordinate the pipe condition assessmenttesting.• The Contractor shall allow DCWASA’s Corrosion Consultant 4 hours to inspectand test the pipe. The Contractor shall completely expose and cleanapproximately 4 feet of pipe so that DCWASA’s Corrosion Consultant can obtainfull access to the pipe to conduct the inspection and testing of the pipe.• Following completion of the testing, the Corrosion Consultant will advise theDCWASA Inspector of the suitability of the pipe to receive the wet-tap. If thepipe is deemed in suitable condition for wet-tapping, the Contractor will beauthorized to proceed with the wet-tapping operation. The Contractor shallcoordinate the time and date of the work with the DCWASA Inspector.• If the main is found to be unsuitable for wet-tapping, the Contractor will beadvised that the connection to the main shall be made by dry cut operations andnot by wet-tapping. Under these conditions the Contractor shall coordinate theshutdown of the main with the DCWASA Inspector. This shutdown may requirerescheduling the work depending on the availability of DWS crews to shutdownthe main.4. WASA Inspection• No work associated with the wet-tapping of water mains shall be undertakenwithout a DCWASA Inspector present. The Contractor shall provide theDCWASA Inspector at least three (3) days notice to schedule when wet-tappingoperations are to take place.• Following completion of the wet-tap, the Contractor shall provide the pipe couponto the DCWASA Inspector. The pipe coupon will be tagged by the inspector anddelivered to DCWASA’s Corrosion Consultant for further testing and evaluation.5. Contractor Experience and Qualifications• Wet-tapping of water mains shall only be made by individuals experienced andqualified in wet-tapping operations and procedures.Revised 1/25/2006 3
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procedures for wet-tapping water mains - DC Water

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