Page 355 - Challenges in Corrosion Costs Causes Consequences and Control(2015)
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CORROSION DAMAGE, DEFECTS, AND FAILURES 333
Figure 5.4 Tape-wrapped air valve. (David Raymond, City of Ottawa, Public Works &
Services.)
The use of wax taping and magnesium anode resulted in very little corrosion,
requiring the normal maintenance and inspection of the chamber for valve integrity.
Corrosion of bolts in areas other than valves was observed as shown in Figures 5.5
and 5.6. The economies of cathodic protection compared with the replacement of the
water main are illustrated in Table 5.6.
Figure 5.5 Four-inch T-bolt from 8-in valve. (David Raymond, City of Ottawa, Public Works
& Services.)