Nace CP 1, Course Manual

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RP0176-2003
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NACE International
Lye, R.E. “Cathodic Protection and Coating—Design and
Performance of a Corrosion Protection System for a
North Sea Jacket.” CORROSION/89, paper no. 282.
Houston, TX: NACE, 1989.
McCrory, E.D. “Maintenance of Protective Coating Systems
on Offshore Platforms.” JPCL 3, 4 (1986): pp. 26-31.
Morgan, J.H. Cathodic Protection. Houston, TX: NACE,
1987.
Peabody, A.W. “Sound Applications for Zinc Anodes.” St.
Louis, MO: American Zinc Institute, 1954.
“Platinized Titanium Anodes for Cathodic Protection.” Tech-
nical Bulletin . East Newark, NJ: Engelhard Industries,
Inc., 1966.
Rau, J.F., T.W. Michie, and S.N. Smith. “Cathodic Protec-
tion of Guyed Tower in 1,000 ft of Water.” CORRO-
SION/87, paper no. 76. Houston, TX: NACE, 1987.
Reding, J.T., and T.D. Boyce. “Cathodic Protection Perfor-
mance of Offshore Anodes at a Simulated Depth of
650 Feet.” MP 13, 9 (1974): pp. 37-40.
Rosbrook, R., W.H. Thomason, and J.D. Byrd. “Flame
Sprayed Aluminum Coatings on Subsea Components.”
MP
28, 9 (1989): pp. 34-38.
Schrieber, C.F., and J.T. Reding. “Field Testing a New Alu-
minum Anode.” Materials Protection 6, 5 (1967): pp.
33-36.
Smith, S.N., C.F. Schrieber, and R.L. Riley Jr. “Supple-
mental Studies of the Galvalum III Anode—Exposure
Time and Low Temperature.” CORROSION/77, paper
no. 35. Houston, TX: NACE, 1977.
Smith, S.N, J.T Reding, and R.L. Riley Jr. “Development of
a Broad Application Saline Water Aluminum Anode—
Galvalum III.” MP 17, 3 (1978): pp 32-36.
Stauffer, D.B. “Structural Design for Offshore Engineering.”
Australian Corrosion Engineering (June 1959): p. 3.
Sverdrup, H.V., M.W. Johnson, and R.H. Fleming. The
Oceans . New York, NY: Prentice-Hall, 1952.
Szoklik, A. “Maintaining Protective Coatings on Offshore
Platforms.” JPCL 5, 5 (1983): pp. 32-40.
Szoklik, A. “Splash Zone Protection: A Review of 20 Years
in the Bass Strait.” JPCL 6, 12 (1989): pp. 46-55.
Thomason, W.H. “Offshore Corrosion Protection with Ther-
mal-Sprayed Aluminum.” Proceedings of the 17th An-
nual Offshore Technology Conference, paper no. 4971
(1985).
Thomason, W.H., S.E. Pape, and S. Evans. “The Use of
Coatings to Supplement Cathodic Protection of Off-
shore Structures.” MP 26, 11 (1987): pp. 22-27.
Townley, D.W. “Unified Design Equation for Offshore Cath-
odic Protection.” CORROSION/97, paper no. 473.
Houston, TX: NACE, 1997.
Uhlig, H.H. Corrosion Handbook. New York, NY: John
Wiley and Sons, Inc., 1948.
Vennett, R.M., and R.R. Matthews. “Stratification of Water
Properties Along the Louisiana Coast and Its Influence
on Cathodic Protection Systems.” MP 14, 7 (1975):
pp. 31-39.
Wang, W., and W.H. Hartt. “Experimental Protocol and
Data Representation for Sacrificial Anode Cathodic
Protection of Steel in Seawater.” CORROSION/93,
paper no. 520. Houston, TX: NACE, 1993.
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Appendix A: Typical Design Parameters for Offshore Petroleum Production
Structures in Selected Oil Provinces
The principal factor governing the minimum design current
density at which polarization necessary for complete CP
can be achieved in the open sea is the availability of corro-
sive (depolarizing) agents, principally oxygen, at the sub-
merged structure surfaces. Lowering the water temperature
increases both the water resistivity and oxygen solubility.
Water turbulence, along with natural lateral flow, also maxi-
mizes the rate at which oxygen reaches the structure sur-
faces. Cook Inlet waters represent an environmental ex-
treme; most of the above negative factors are present, in
addition to scouring (mechanical depolarization) by sus-
pended glacial silt in the swiftly flowing water.
The formation of a calcareous deposit also affects the cur-
rent requirement by reducing the ability of oxygen to reach
the metal surface. The calcareous deposit precipitates from
seawater because of the alkaline shift in pH that results
from the polarization of the metal surface. Because the
beneficial qualities of the calcareous deposit are reduced by
decreasing water temperature and lower current densities, a
relatively high initial current provision for CP can reduce the
long-term current demand to maintain protection.
Laboratory and field tests have shown that rapid polariza-
tion of a steel cathode upon immersion to potentials of -0.9
to -1.0 V (Ag/AgCl [sw]) generates a more protective calcar-
eous deposit than is achieved by slower polarization. High