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ETL 1110-9-10(FR)
5 Jan 91
SECTION 3
TABLES
Table 3-1. Range of current density requirements for cathodic
protection of uncoated steel.
Environment
Current density
(mA/sq ft of bare steel)
APM 88-9a
Gerrardb
Othersc
Neutral soil
0.4
to 1.5
0.4
to 1.5
0.5
to 1.5
Well--aerated neutral soil
2
to 3
2
to 3
1.5
to 3
Wet soil
1
to 6
2.5
to 6
1
to 3
Highly acidic soil
3
to 15
5
to 15
3
to 15
Soil-supporting active sulfate-
reducing bacteria
6
to 42
Up to 42
----------
Heated soil
3
to 25
5 to 25
3 or more
Stationary freshwater
1
to 6
Up to 5
1.5 to 3
Moving freshwater
----- ------
--------
3
to 8
Moving freshwater containing
----------
dissolved oxygen
5
to 15
5 to 15
Seawater (depending on velocity,
temperature & oxygen content
3
to 10
5 to 25
5
to 50
a
Corrosion Control, Air Force Manual (AFM) 88--9 (Headquarters, U.S. Air Force,
August, 1962), ch. 4, p. 203.
b
J.S. Gerrard, "Practical Applications of Cathodic Protection," Corrosion,
(Newnes-Butterworths, London, 1976), vol. 2, p 11:65. Used with permission.
c
Data based on the experience of other Professional Cathodic Protection
engineers.
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