Leaking Copper Pipes

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    • #273322
      Avatar photoMasterPlumbers

        What would make the plumbing in a house (copper piping) start leaking inmany different areas
        with no obvious problems detected with the electrical system.

        Tony Bifulco

      • #287367
        Avatar photoSylvanLMP

          High water velocity may be caused by an
          undersized piping system or excessive pressure. . The
          real solution is to lower the water velocity. The relationship is as
          follows: Reduce pipe size, increase velocity; increase pipe size, reduce
          velocity. Recommended velocity for hot water in a copper tube system is 4 –
          5 feet per second (fps). If systems are designed to respect these velocities
          the return lines will last as long as the rest of the system. The practice
          of reducing tube diameter for the return line run is counter-productive and
          is the main cause of high velocity in these systems. Since there is no
          sizing guide in the Model Codes for return lines, there is little guidance
          for the plumber on how to size this portion of the system. In the course of
          installing or replacing circulating lines, some contractors have been
          increasing the size of the return loop piping to 1″ or at least the same
          diameter as the hot water supply out of the water heater.
          Numerous, abrupt changes in direction in the piping system. Where
          structural conditions cause numerous directional changes, long radius (1.5
          Diameter) fittings should be used to minimize the interruption of laminar
          flow. .

          In other words you need either a pressure reducing valve OR increase the diameter of the piping. You should also have the water tested for PH content

          Another factor affecting copper tubing is if the instlaller didnt ream the tubing ends prior to soldering this would turbulent flow and erosion as lack of reaming the tube ends. Burrs left on the ID of the tube can
          cause interruption of laminar flow resulting in localized high water
          velocity and cavitation.

          Protrusions into the flow stream caused by excessive lumps of
          solder/brazing material, improperly fabricated tees (branch protruding into
          the run pipe), etc. These protrusions can also cause the
          interruption of laminar flow resulting in localized high water velocity and

          A lot of misfits also use self cleaning (ACID) fluxes and never properly flush the system (joints) and over time this flux actually eats away at the base metal.

          Excessive water temperature. Heating water above 140 degrees Fahrenheit
          can accelerate the process of erosion/corrosion. As the temperature
          increases, the velocity should be lowered. At 180 degrees Fahrenheit, the
          velocity should be down around 2 – 3 feet per second (fps).

          Bear in mind that these conditions are not peculiar to copper tube, but can
          affect other materials as well. However, when erosion/corrosion does occur
          in copper tube it is readily identifiable by the horseshoe shaped pitting
          throughout the inside of the tubes. Identification OD these pits or grooved
          corrosion-product-free areas on the inside of the tube can help you
          determine that water velocity is too high and that the reduction of velocity
          can correct the condition. Good luck

        • #287368
          Avatar photoMike_Pantone1

            Please post more details for discussion. We have a neighborhood that has 60+ homes that have 1 to 14 leaks occur in last 6 months. For 3 possible causes, see posting by SteveG. on 9/16/00 titled Pin hole leaks in copper.

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