Assessment of Corrosion under Insulation and Engineered Temporary
Wraps using Pulsed Eddy-Current Techniques
Bill J. Brown and Mike Dixon
TRAC Oil & Gas Ltd, Aberdeen,
UK
Maxim Morozov*, Gordon Dobie and Anthony Gachagan
University of Strathclyde Abstract
Inspection of Corrosion under Insulation (CUI) and material degradation under
Engineered Temporary Wraps (ETW) has proven to be a challenge to reliably detect
and monitor using a number of NDT methods. Pulsed eddy-current has recently been
identified as a potential NDT method for this application. Importantly, the lift-off
between the sensor and the structure being inspected can accommodate the insulation or
ETW layer. This work evaluates the effectiveness of current instrumentation to detect
and assess the degradation under in-service conditions. Moreover, the components
tested and the degradation effects are representative of those found in-service. A
comprehensive inspection and recording process has been undertaken and the resultant
data analysed to identify operating constraints of the method relative to typical
components, representative degradation, dimensions of the degradation and standoff
ranges.
1. Introduction
Carbon steel is a widespread construction material used for the offshore structures in the
oil and gas industry [1]. Carbon steel is an alloy of carbon and iron containing up to 2 %
mass fraction carbon, up to 1.65 % mass fraction manganese, up to 0.60% of silicon and
residual quantities of other elements [2].
Offshore installations are subject to corrosive environment and heavy operational
conditions including elevated temperatures and loads which impose high requirements
on the structural integrity of these structures [3]. External corrosion of carbon steels is determined by the marine atmospheric
environment containing water and chloride salts [1]. Corrosion under insulation (CUI) is
a significant problem associated with offshore carbon steel structures. Internal corrosion
of carbon steel in oil and gas industry is mainly caused by water and dissolved oxygen
in the petrochemical products and can have following mechanisms [1, 4]:
• CO2 and H2S corrosion
• Microbiologically induced corrosion
• Sulfide stress cracking (SSC)/stress corrosion cracking (SCC) caused by H2S
• Hydrogen-induced cracking/step-wise cracking (HIC/SWC)
• Alkaline stress corrosion cracking (ASCC).
2
Traditional methods of NDT used for corrosion monitoring in offshore oil and gas
installations encompass visual examination, ultrasonic testing (UT), acoustic emission
(AE), radiography, eddy current testing (ECT) and magnetic flux [4].
UT requires preliminary surface preparation and acoustic couplant (often water). UT is
not suitable for CUI without removing insulation which is a costly operation. Corrosion
reactions generate elastic waves which can be detected by AE sensors. The main
disadvantage of AE technique is that offshore environment is generally noisy and the
AE signals are weak resulting in poor signal-to-noise ratio. Radiography is only suitable
for limited pipe diameters and involves ionising radiation hazardous for the inspectors.
MFL is efficient when deployed from inside a pipe. Sensitivity of MFL quickly
decreases at large standoffs determined by the insulation when testing from outside a
pipe/vessel.
ECT is a non-contact electromagnetic NDT technique based on induction of eddy
currents in an electrically conducting test piece by means of an excitation coil and
detection of the EC response either by any suitable sensor(s), as shown in Figure 1 [5].
Pulsed Eddy Current (PEC) is an electromagnetic technique using rectangular magnetic
field excitation (see Figure 2a) which induces eddy currents in the steel wall [6, 7].
NDT of ferromagnetic metallic components by means of PEC is regulated by BS ISO 20669:2017 [5]. Insulation and weather jacket constitute coating [5].
Figure 1. Eddy currents testing of a component under coating [5]: 1 sender coil, 2 receiver devices, 3
primary magnetic field, 4 secondary magnetic field, 5 eddy currents, 6 cover/sheeting, 7 insulation, 8
tested component
The eddy currents pulse diffuses into the test specimen until it reaches the far surface.
Secondary magnetic field of eddy currents is acquired by the receiver device of the PEC probe [8]. The moment in time when the EC first reach the far surface is indicated
by a sharp decrease in the received PEC signal shown in Figure 2b [6]. Beginning of the
sharp decrease (bending point) is the measure of wall thickness. PEC is highly efficient
for evaluation of corrosion under coatings [9] and is being to monitor wall thickness of
offshore steel structures [10].
3
This paper presents results of evaluation of wall thickness of carbon steel pipes with
internal corrosion and external corrosion under insulation by means of state-of-art PEC
instrumentation. A comprehensive inspection and recording process has been
undertaken and the resultant data analysed to identify operating constraints of the
method relative to typical components, representative degradation, dimensions of the
degradation and standoff ranges.
Figure 2. (a) PEC excitation signal; (b) PEC response signal
2. Methodology 2.1 Samples
The following carbon steel samples were examined in this study: 1) TRAC Sample 1, a Blistered Pipe, shown in Figure 3 which illustrates extension of
CUI in this sample without insulation and aluminium weather jacket which were
applied during testing:
• Outer diameter: 331.0 mm
• Nominal wall thickness: 10.5 mm
• Insulation: 50.0 mm
• Weather Jacket: Aluminum 1.0 mm
• Corrosion type: external CUI 2) TRAC Sample 2, Epoxy Coated, Figure 4: • Outer diameter: 200.0 mm
• Nominal wall thickness: 10.5 mm
• Coating: epoxy 5.0 mm
3)
• Corrosion type: Pipe with drilled holes:
internal
• Outer diameter: 160.0 mm
• Nominal wall thickness: 8.0 mm
• Artificial defects: through holes with diameters of 25mm and 50mm
4
Probe Nominal lift-off range, mm Nominal footprint, mm
P1 (small) 0 – 20 60
P2 (medium) 20 – 50 120
Figure 3. TRAC Sample 1
Figure 4. TRAC Sample 2
2.2 Experimental setup
The following commercial PEC instrumentation was used in this study: eddyfi Lyft and
Maxwell NDT. Figure 5 shows the used PEC instrumentation: (a) eddyfi Lyft with
various probes, (b) Lyft probe PEC-089-G2-HT05S, (c) Maxwell NDT PECT, (d)
Maxwell NDT small probe P1 and medium probe P2. Properties of the LYFT probe
were as follows:
• Model: PEC-089-G2-HT05S
• Probe Footprint: 95.2 mm
• Circumferential Footprint: 124.5 mm
Properties of Maxwell NDT probes are given in Table 1.
Table 1. Maxwell NDT probes
5
(a) (b)
(c) (d)
Figure 5. PEC instrumentation used: (a) eddyfi Lyft with probes, (b) Lyft probe PEC-089-G2-HT05S, (c)
Maxwell NDT PECT, (d) Maxwell NDT small probe P1 and medium probe P2
2.3 Thickness Measurement Approach
Coordinate grids were applied to sections of the tested samples. C-scans (2D surface
images) of each section were acquired in grid-mapping mode using both eddyfi Lyft
PEC-089-G2-HT05S probe and Maxwell PECT with an appropriate probe depending on
the nominal wall thickness and standoff. Standoff was varied either by placing coating
(combination of insulation and weather jacket) upon the sample or using plastic spacers.
3. Results and discussion
3.1 Eddyfi Lyft
Figure 6 shows C-scan acquired using Eddyfi Lyft on the TRAC Sample 1 with
insulation and weather jacket.
6
mfe
ren
tial [m
m]
Axial [mm]
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250
0 10.6 10.8 10.8 10.6 10.4 9.9 9.7 9.9 10.0 10.3 10.5 9.9 9.5 9.8 10.2 10.1 10.1 10.0 10.1 9.7 9.1 9.0 8.8 8.2 8.1 9.1
50 10.9 10.9 10.8 10.8 10.5 10.2 9.9 9.8 9.9 10.3 10.6 10.2 9.8 10.0 10.3 10.2 10.2 10.1 10.2 10.0 9.4 9.2 8.9 8.4 8.4 9.3
100 10.9 10.9 10.9 10.9 10.6 10.3 10.0 9.8 9.9 10.6 10.7 10.3 10.2 10.4 10.3 10.2 10.2 10.3 10.5 10.2 9.6 9.3 9.0 8.5 8.8 9.6
150 11.0 11.0 10.9 10.9 10.6 10.4 10.2 10.0 10.2 10.7 10.7 10.5 10.4 10.5 10.3 10.2 10.3 10.5 10.6 10.3 9.7 9.5 9.3 8.7 9.3 9.9
200 11.1 11.0 11.0 10.8 10.6 10.5 10.4 10.3 10.4 10.7 10.6 10.5 10.5 10.4 10.3 10.3 10.4 10.6 10.7 10.2 9.7 9.8 9.4 8.9 9.6 10.0
Cir
cu
250 11.1 10.9 11.0 10.9 10.8 10.6 10.6 10.6 10.6 10.6 10.4 10.4 10.4 10.4 10.3 10.4 10.5 10.7 10.6 10.1 9.6 9.9 9.6 9.2 9.7 10.1
300 11.1 11.0 11.0 10.9 10.9 10.8 10.7 10.8 10.7 10.5 10.4 10.5 10.5 10.4 10.3 10.4 10.5 10.7 10.5 9.9 9.6 10.0 9.8 9.3 9.7 10.2
350 10.7 10.9 11.0 11.0 10.9 10.9 10.8 10.7 10.7 10.5 10.4 10.4 10.4 10.3 10.3 10.3 10.6 10.7 10.5 9.9 9.7 10.0 9.9 9.5 9.7 10.2
400 10.7 10.7 10.9 11.1 11.0 10.8 10.9 10.8 10.6 10.3 10.4 10.4 10.3 10.2 10.2 10.3 10.5 10.5 10.4 9.9 9.8 10.2 10.0 9.5 9.4 8.7
Figure 6. Eddyfi Lyft: TRAC Sample 1 with insulation and weather jacket
3.2 Maxwell PECT
Figure 7 shows C-scan acquired using Maxwell PECT & medium probe P2 on the
TRAC Sample 1 with insulation and weather jacket. It shows a good qualitative
agreement with Eddyfi Lyft results. Average deviation between Maxwell and Eddyfi
Lyft results is 0.23mm, maxim deviation being 0.75mm. Figure 8 shows C-scan
acquired using Maxwell PECT & medium probe P2 on the TRAC Sample 1 with
insulation without weather jacket. Average deviation between results for the TRAC
Sample 1 with insulation and with and without weather jacket acquired with Maxwell
PECT is 0.10mm.
Figure 7. TRAC Sample 1 with insulation and weather jacket
Figure 8. TRAC Sample 1 with insulation without weather jacket
7
Axial [mm]
0 20 40 60 80 100 120 140 160 180 200
0 10.5 10.7 10.5 10.4 10.8 10.6 10.1 10.3 10.1 10.0 10.0
23 10.3 10.2 10.3 9.8 9.5 9.8 9.6 10.0 10.2 10.3 10.3
[mm
]
46 9.9 9.9 9.5 8.7 8.7 8.8 9.0 9.6 10.0 10.3 10.4
en
tia
l
69 10.1 9.8 9.4 8.7 8.7 8.9 9.2 9.6 9.6 10.2 10.3
u m
fer
92 10.1 9.9 9.5 9.3 9.4 9.3 9.7 10.0 10.2 10.1 10.0
Cir
c
115 10.1 9.9 9.6 9.9 10.5 10.2 10.5 10.2 10.2 10.1 10.0
138 10.2 9.9 9.9 10.0 10.1 10.2 10.4 10.3 10.3 10.1 10.3
161 10.7 10.6 10.3 10.4 10.1 10.6 10.7 10.8 10.7 10.7 10.6
Figure 9. Individual blister without corrosion product (scab) in contact (no coating)
Axial [mm]
0 20 40 60 80 100 120 140 160 180 200
0 10.5 10.3 10.2 10.1 10.1 10.1 10.2 10.1 10.0 9.8 9.4
23 10.4 10.4 10.2 10.1 10.0 9.8 9.9 9.9 10.0 9.9 9.6
[mm
]
46 10.4 10.2 10.0 9.8 9.7 9.7 9.7 9.8 9.9 9.9 9.8
en
tia
l
69 10.3 10.3 10.0 9.8 9.6 9.6 9.7 9.8 9.9 9.9 10.0
u m
fer
92 10.2 10.2 10.0 9.8 9.7 9.7 9.8 9.9 10.1 10.1 10.1
Cir
c
115 10.2 10.1 10.1 10.0 9.9 9.9 10.0 10.0 10.2 10.3 10.3
138 10.1 10.1 10.1 10.2 10.2 10.2 10.2 10.4 10.4 10.6 10.6
161 10.1 10.2 10.3 10.4 10.5 10.5 10.6 10.6 10.7 10.8 10.9
Figure 10. Individual blister without corrosion product (scab) through insulation and weather jacket
An individual blister located on the TRAC Sample 1 was scanned both in contact and
through coating (insulation and weather jacket) with corrosion products (scab) of
thickness above 5mm present and after corrosion products were mechanically removed.
Figure 9 shows C-scan of the individual blister without corrosion product (scab) in
contact (no coating) acquired using small probe P1. Figure 10 shows C-scan of the
individual blister without corrosion product (scab) through insulation and weather jacket
acquired using medium probe P2. Average deviation with respect to the contact
measurements is 0.31mm, maximum deviation being. This result demonstrates that
presence of coating within the operating range of PEC equipment does not significantly
influence results. Figure 11 shows C-scan of the individual blister with corrosion
product (scab) through insulation and weather jacket acquired using medium probe P2.
Average deviation with respect to the case of no corrosion product is 0.36mm,
maximum deviation being 0.57mm. This result demonstrates that moderate amount of
corrosion product does not significantly influence results.
Figure 12 shows C-scan acquired in contact using P1 probe on the Enquest sample with
internal corrosion and erosion channel.
Figure 13 shows C-scan acquired in contact using small P1 probe on the sample with a
hole of 25mm diameter. The PEC signature of a hole is clearly detectable although the
thickness readings in the centre of the hole are higher than 0mm due to EC response
averaging effect over the probe footprint. Figure 14 shows C-scan acquired at standoff
of 20mm using small P1 probe on the sample with a hole of 25mm diameter. Thickness
readings in the centre of the hole are higher compared to the contact measurement (see
Figure 13) since the effective footprint of the probe increases with standoff as 1.5 x
8
rc u
m
(Standoff + Wall Thickness). Figure 15 shows C-scan acquired at standoff of 20mm
using small P1 probe on the sample with a hole of 50mm diameter. As expected,
thickness readings in the centre of the larger hole are lower than that in case of the
25mm hole (Figure 14) since the average “weight” of the no-metal signal is higher for
the bigger hole.
Axial [mm]
0 20 40 60 80 100 120 140 160 180 200
0 10.5 10.1 10.0 9.9 9.7 9.7 9.8 9.8 9.7 9.4 9.2
23 10.0 10.0 9.9 9.7 9.6 9.6 9.5 9.7 9.6 9.4 9.2
[mm
]
46 10.0 9.9 9.7 9.5 9.4 9.5 9.5 9.5 9.5 9.5 9.5
en
tia
l
69 10.0 9.9 9.6 9.4 9.3 9.4 9.5 9.5 9.6 9.6 9.6
u m
fer
92 9.8 9.8 9.6 9.5 9.4 9.4 9.5 9.6 9.7 9.8 9.7
Cir
c
115 9.8 9.7 9.7 9.6 9.6 9.5 9.6 9.7 9.8 9.9 9.9
138 9.8 9.7 9.8 9.8 9.8 9.8 9.9 10.0 10.0 10.1 10.0
161 9.8 9.8 10.0 10.0 10.0 10.1 10.1 10.2 10.3 10.3 10.3
Figure 11. Individual blister with corrosion product (scab) through insulation and weather jacket
Axial [mm]
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800 820 840
0 19.0 18.9 18.7 18.9 18.8 18.9 19.1 18.9 19.0 18.9 18.8 18.7 18.5 18.4 18.3 18.1 18.4 18.4 18.0 17.9 18.0 17.4 17.6 18.0 18.6 18.5 18.3 18.3 18.2 18.3 18.9 18.9 18.9 18.5 18.6 18.4 18.0 18.2 18.3 18.3 18.1 18.0 18.4
23 18.7 18.4 18.0 18.1 18.1 18.0 18.2 18.6 18.7 18.7 18.6 18.4 17.9 17.7 17.5 17.8 17.4 17.7 17.4 17.4 17.5 16.9 17.2 18.0 18.2 18.3 18.0 17.9 17.6 17.7 18.1 18.3 18.4 18.4 18.6 18.4 18.4 18.7 18.9 18.6 18.4 18.1 18.7
46 18.1 17.2 16.1 15.7 15.8 16.0 16.5 16.8 17.1 17.6 17.5 16.5 15.8 15.8 15.6 15.7 16.0 16.1 16.0 15.7 16.1 16.1 16.8 17.1 17.0 17.1 16.8 16.6 16.3 16.4 16.5 16.7 17.1 17.2 17.4 17.7 17.9 18.2 18.5 18.6 18.2 18.2 18.4
m]
69 15.9 15.0 13.8 13.6 13.8 14.1 14.4 14.7 15.1 15.6 15.5 14.6 13.8 13.7 13.8 13.4 13.7 13.7 13.5 13.7 14.1 14.3 15.1 14.6 14.9 14.5 14.6 14.3 13.7 13.5 13.7 13.9 14.4 14.5 14.9 15.4 15.9 16.7 17.1 17.4 17.4 17.7 17.5
ial
[m
92 13.7 13.0 12.6 12.5 12.4 12.6 12.8 12.9 13.2 13.4 13.5 12.8 12.4 12.2 12.2 12.0 11.9 11.7 11.7 11.8 11.9 12.6 12.9 12.8 12.6 12.4 12.5 12.0 11.5 11.4 11.4 11.6 11.5 11.6 11.7 12.3 13.3 14.2 15.0 15.8 16.3 16.4 15.8
fere
n t
115 12.1 11.9 11.9 11.8 11.9 11.9 11.9 12.0 12.0 11.9 11.9 11.9 11.6 11.4 11.5 11.2 11.1 10.7 10.7 10.5 10.8 11.8 13.1 13.2 13.1 13.4 12.9 12.4 12.1 12.2 11.8 10.9 10.8 10.2 9.9 9.9 10.6 11.6 12.6 14.0 14.7 15.6 14.1
138 11.9 11.8 11.7 11.8 11.9 12.0 11.9 11.9 11.8 11.8 11.8 11.8 11.7 11.6 11.6 11.4 11.2 11.0 10.8 10.7 11.1 12.6 14.4 15.1 15.7 15.6 15.3 15.0 14.7 14.8 14.1 13.2 12.4 11.1 10.1 9.3 9.8 10.7 11.8 13.0 14.6 15.0 13.3
Ci
161 13.1 12.8 12.7 12.6 12.7 12.9 12.7 12.7 12.7 12.8 12.9 12.9 13.1 13.1 13.2 13.0 13.1 13.0 12.8 12.7 13.0 14.3 15.5 16.2 16.3 16.5 16.7 16.3 16.0 15.9 15.5 15.2 14.5 13.2 12.3 12.1 12.3 13.0 13.7 14.5 15.7 15.8 14.5
184 14.5 13.9 13.8 13.7 13.9 14.0 13.7 13.8 14.1 14.3 14.6 14.9 14.9 15.2 15.2 15.2 15.4 15.5 15.4 15.3 15.5 16.2 16.7 17.0 16.4 16.9 17.1 16.9 16.3 16.1 16.2 16.4 16.2 15.7 15.1 15.2 15.3 15.7 16.1 16.7 17.1 16.7 15.9
207 16.5 15.5 15.3 15.3 15.7 15.9 15.8 15.8 16.1 16.4 16.9 17.3 17.5 17.3 17.0 17.0 17.2 17.5 17.7 17.5 17.7 17.9 18.0 17.4 17.1 17.6 17.8 17.8 16.7 16.8 16.9 17.2 17.2 17.4 17.1 17.3 17.6 17.6 17.6 18.2 18.1 18.0 17.6
230 17.4 16.7 16.6 17.0 17.3 17.7 17.8 17.6 17.9 17.9 18.1 18.6 18.8 18.7 18.2 17.8 17.7 18.2 18.3 18.2 18.4 18.4 17.9 17.7 18.2 18.2 18.3 17.9 18.0 17.9 17.8 17.7 18.2 18.3 18.4 18.5 18.5 18.5 18.3 18.4 18.7 18.5 18.3
253 17.7 17.1 17.2 17.6 18.0 18.4 18.3 18.1 18.5 18.3 18.1 18.3 18.6 18.5 18.1 17.6 17.6 17.8 18.2 18.1 18.2 18.0 17.8 17.7 18.2 18.2 18.0 18.1 17.9 18.5 18.4 18.1 18.4 18.3 18.6 18.7 18.0 18.2 18.1 18.1 18.4 18.4 18.4
Figure 12. Enquest sample with internal corrosion and erosion channel
Ax ial [mm]
0 23 46 69 92 115 138 161 184 207 230 253 276
mm
]
0 8.0 8.0 7.9 7.8 7.7 7.6 7.7 7.9 8.0 8.0 7.8 7.9 7.9
en
tia
l [
20 7.9 7.9 7.8 7.8 7.7 7.6 5.9 7.4 8.0 8.0 8.1 8.1 8.0
u m
fer
40 7.8 7.8 7.8 7.8 7.7 7.8 4.8 6.8 8.1 8.1 8.2 8.0 7.9
Cir
c
60 7.7 7.8 7.8 7.7 7.7 7.7 6.3 7.8 8.1 8.1 8.1 8.0 7.8
80 7.8 7.8 7.8 7.7 7.8 7.9 8.0 8.1 8.1 8.2 8.2 8.0 7.9
Figure 13 Hole ⌀25mm in contact
Ax ial [mm]
0 23 46 69 92 115 138 161 184 207 230 253 276
mm
]
0 8.0 8.2 8.1 8.1 8.0 7.9 7.7 7.9 8.2 8.3 8.3 8.3 8.2
en
tia
l [
20 8.0 8.1 8.1 8.0 8.0 8.0 6.3 7.3 8.3 8.3 8.3 8.3 8.2
u m
fer
40 7.9 8.0 8.1 8.1 8.0 8.2 5.8 7.3 8.4 8.4 8.4 8.4 8.2
Cir
c
60 8.0 8.0 8.0 8.0 7.9 8.0 7.1 7.6 8.3 8.4 8.5 8.3 8.2
80 8.0 8.0 8.0 8.0 8.0 8.1 8.0 8.2 8.4 8.5 8.5 8.4 8.1
Figure 14 Hole ⌀25mm at 20mm standoff
9
Ax ial [mm]
0 23 46 69 92 115 138 161 184 207 230 253 276
0 8.0 8.0 8.0 8.1 8.1 7.8 7.5 7.5 7.8 8.0 8.0 7.9 7.9
mm
]
20 8.0 8.2 8.1 8.1 8.1 7.7 5.9 6.5 7.7 8.0 8.0 7.9 7.9
en
tia
l [
40 8.1 8.2 8.3 8.1 8.3 7.7 4.1 4.5 7.9 7.9 8.0 8.0 8.0
u m
fer
60 8.1 8.2 8.1 8.2 8.3 7.8 4.0 4.4 8.1 8.0 8.0 8.1 8.1
Cir
c
80 8.0 8.0 8.0 8.2 8.1 7.3 4.5 5.1 7.8 8.0 8.0 8.0 8.0
100 8.0 8.1 8.0 8.0 8.0 7.4 6.3 7.0 7.7 7.9 7.9 8.0 8.0
120 8.0 8.0 8.0 8.0 7.9 7.8 7.4 7.5 7.7 7.8 7.9 7.9 7.9
Figure 15 Hole ⌀50mm at 20mm standoff
3. Conclusions
This work presented results of PEC NDT to detect and evaluate corrosion in offshore
carbon steel structures. The components tested and the degradation effects are
representative of those found in-service. A comprehensive inspection and recording
process has been undertaken and the resultant data analysed to identify operating
constraints of the method relative to typical components, representative degradation,
dimensions of the degradation and standoff ranges. • Wall thickness was measured through insulation of 50mm and aluminium weather
jacket in walls of thickness up to 20mm with accuracy of 0.25mm; • Thin aluminium weather jacket has virtually no impact on results;
• Standoff increases the area over which thickness is averaged;
• Larger probe footprint increases the area over which wall thickness is averaged;
• Corrosion products (ferromagnetic scab) of thickness of up to 10mm has similar
influence on the PEC response as standoff;
• Holes in walls of thickness of 8mm produce an indication in C-scan when scanned
with medium (P2) probe at stand-off distance of up to 20mm.
Acknowledgements
This work is funded by the Centre Sensor and Imaging Systems (CENSIS) and TRAC
Oil & Gas Ltd in partnership with the Oil & Gas Technology Centre (OGTC).
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