This powerpoint presentation begins by providing a brief overview of non-uniform copper corrosion and flow electrification. Laboratory scale studies were done to investigate the
effects of flow
electrification and
pitting on a series of
copper piping. Conclusions on the effects of flow rate on
flow electrification indicate the following:
flow electrification was observed at all velocities
tested between 0.9-6.6 fps and was worst at 2.8 fps;
an optimally "bad" flowrate may exist resulting in
higher currents between first and last pipe to
contact flow; and, pitting might still occur at no flow and at high
flow, but the rate may be reduced. The impacts of sulfide on flow electrification were examined
to determine the
effects of sulfide
on flow
electrification. Sulfide conclusions indicate that:
the presence of sulfides made the portion of pipe that first
contacts flow cathodic relative to later sections; and,
flow electrification effects were highest when the sulfide
concentration was highest. The effects of inhibitors on flow electrification
in a recirculation rig were examined
to study the effects of various inhibitors on a known pitting
water. Presentation conclusions indicate the following:
observed flow electrification in numerous
experiments; the magnitude of the flow electrification increased
with higher Cl<sub>2</sub> and varied with flow rate; zinc orthophosphate had the largest positive impact
on electrochemical measures of pitting;
the presence of sulfides made the portion of pipe that
first contacts flow cathodic relative to downstream
sections; and,
the magnitude of flow electrification and its sign depend
on the water. Includes figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.6 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 32 |
| Published : | 11/01/2008 |
