Nace CP 1, Course Manual

Page: 352 / 535

RP0176-2003
30
NACE International
14.5.2.2 The inspector should note total job pro-
gress of the entire crew per day and record as
total m
2
(ft
2
) per day.
14.5.3 The job may be evaluated using data from Par-
agraphs 14.5.1 through 14.5.2.2 as measures of crew
efficiency and cost per m
2
(ft
2
).
14.5.4 Complete records should be kept so that coat-
ing systems can be evaluated on the basis of cost per
m
2
(ft
2
) per year.
________________________________________________________________________
Section 15: Corrosion Control Records
15.1 Introduction
15.1.1 This section describes a system of corrosion
control records for documenting data pertinent to the
design, installation, operation, maintenance, and effect-
tiveness of the CP and coating systems.
15.1.2 Included in this section is an exhaustive listing
of possible records. Each operator should decide on
the records that are necessary for control of corrosion
on the structure.
15.1.3 Information regarding the location of anodes,
electrical leads, and rectifiers can be conveniently re-
corded on a drawing of the structure being protected.
More of the potential survey data and results of main-
tenance inspections can be maintained in tabular form
and kept up-to-date with periodic entries.
15.1.4 As-built drawings should reflect any changes
from design specifications, particularly deviation in set-
ting depth, which would alter the interval covered by the
splash zone. Deviation in setting depth may occur
through errors in water depth estimate (initial survey) or
through settlement of the structure (possible over field
life).
15.2 CP Systems
15.2.1 Galvanic (sacrificial) anode system—The fol-
lowing should be recorded:
15.2.1.1 Design criteria used: design life,
assumed anode output and consumption rate, and
current density requirements.
15.2.1.2
Number, size, composition, and (if
known) the manufacturer, cost, and supplier of the
anodes.
15.2.1.3 Location of each anode, the method of
attachment, and date of installation. If anodes are
installed during structure construction, the date of
actual setting of the structure offshore should be
recorded.
15.2.1.4
Number and location of anodes if
checked either during construction or after setting
on location, with all discrepancies noted.
15.2.2 Impressed current system—The following
should be recorded:
15.2.2.1 Design criteria used (see Paragraph
15.2.1.1).
15.2.2.2
Number, size, composition, and (if
known) the cost, manufacturer, and supplier of the
anodes.
15.2.2.3 Location of each anode, method of
attachment, and date of installation.
15.2.2.4
Specifications of the direct-current
source.
15.2.2.5 Composition and location of any dielec-
tric shielding used.
15.2.2.6 Current and voltage output of each recti-
fier as called for in Paragraphs 9.3 and 9.5, noting
any adjustments made.
15.2.3 Combination system
15.2.3.1 A combination system is one containing
galvanic (sacrificial) anodes in addition to an im-
pressed current system.
15.2.3.2 Records for a combination system must
include complete information for each of the com-
ponent systems.
15.2.4 Structure potential measurements
15.2.4.1 Each time the potential of the structure is
measured, the type of reference cell and the mea-
suring technique (diver-held, guided, permanent,
or freely suspended) used should be recorded.
15.2.4.2 The structure potential should be re-
corded initially and at the time intervals specified in
Paragraph 9.4.
15.2.5 Operation and inspection—The following
should be recorded:
15.2.5.1 Results of underwater inspection of the
anode system, noting all discrepancies such as
missing anodes.