Coatings and Cathodic Protection · 2018. 6. 9. · Cathodic protection - operational...
19
Coatings and Cathodic Protection CP - Cathodic Protection: basic electrochemical principle basic operational recommendations Electrical resistance of coating and degradation over time Coating disbondment due to CP and other reasons Cathodic Protection – the ultimate safeguard? Performance of Coatings based on Pure Homopolymer Polyisobutene Topics covered in this presentation
Transcript of Coatings and Cathodic Protection · 2018. 6. 9. · Cathodic protection - operational...
-
Co
ati
ng
s a
nd
Cath
od
ic P
rote
cti
on
ØC
P -
Ca
thodic
Pro
tection:
§basic
ele
ctr
ochem
ical pri
ncip
le
§basic
opera
tional re
co
mm
endations
ØE
lectr
ical re
sis
tance o
f coating a
nd d
egra
dation o
ver
tim
e
ØC
oating d
isbond
ment due to C
P a
nd o
ther
reasons
ØC
ath
odic
Pro
tection –
the u
ltim
ate
sa
feguard
?
ØP
erf
orm
ance o
f C
oatings b
ased o
n P
ure
Ho
mopoly
mer
Poly
iso
bute
ne
To
pic
s c
overe
d i
n t
his
pre
sen
tati
on
-
Intr
od
ucti
on
Coatings a
re a
pplie
d o
n b
uried a
nd im
mers
ed m
eta
llic p
ipelin
es in o
rder
to m
inim
ize t
he r
isk o
f corr
osio
n.
Cath
od
ic p
rote
cti
on
-V
+
Rs
oil
RP
ipe
I CP
CP
Pow
er
Supp
ly
Rem
ote
gro
und-
be
dw
ith
Anod
e
Sin
ce p
erf
ect
coatings d
o n
ot
exis
t, c
ath
odic
pro
tection is o
ften insta
lled t
o
act
as a
backup f
or
coating im
perf
ections a
nd d
am
ages.
Coating
dam
ag
e
Rc
oati
ng
I Des
ign
-
Cath
od
ic p
rote
cti
on
– h
ow
it
wo
rks (
1)
1.4
1.0
0.6
0.2
-0.2
-0.6
-1.0
-1.4
-1.8
1
4
7
10
13
Passiv
ity
Corr
osio
n
Imm
unity
Potential vs CSE (V)
pH
-valu
e
Pourb
aix
dia
gra
m o
f Ir
on (
Fe)
Reg
ion
of
inte
rest
for
Cath
od
ic P
rote
cti
on
:
•U
≈
as l
ow
as -
1.5
V
•p
H ≈
4 t
o 1
3
“What
happens if
you p
ut
a p
iece o
f bare
ste
el in
wate
r and a
pp
ly a
pote
ntial?
”
Cath
od
ic p
rote
cti
on
– h
ow
it
wo
rks (
2)
Passiv
ity
Imm
unity
Potential vs CSE (V)
pH
-valu
e
0.8
5V
CS
E
Pourb
aix
dia
gra
m -
Regio
n o
f in
tere
st
for
CP
Acti
vati
on
po
lari
zati
on
:
By s
hifting t
he p
ote
ntial
tow
ard
s n
egative v
alu
es,
inhib
itio
n o
f corr
osio
n
reaction o
f iron o
ccurs
Fe
Fe
2+ +
2e
-
-0.2
-0.6
-1.0
-1.4
4
7
10
13
Co
ncen
trati
on
p
ola
rizati
on
:
Main
tain
ing a
hig
h p
H a
nd
the f
orm
ation o
f a
passiv
ation layer
on t
he
surf
ace c
auses
suppre
ssio
n o
f th
e
corr
osio
n r
eactions.
(CeoC
or
confe
rence 2
014:
M.B
uechle
r, S
GK
, S
witzerland,)
-
Cath
od
ic p
rote
cti
on
- o
pera
tio
nal re
co
mm
en
dati
on
s (
1)
Po
lari
sati
on
po
ten
tial:
Many r
ecom
mendations e
xis
t, m
ain
ly d
ependin
g o
n o
pera
tional
conditio
ns s
uch a
s t
ype a
nd r
esis
tance o
f em
beddin
g (
soil,
wate
r).
NA
CE
SP
0169-2
013
– U
nderg
round o
r subm
erg
ed p
ipes:
Carb
on s
teel -0
.95 V
vs C
opper
Sulp
hate
Ele
ctr
ode (
CS
E)
ISO
15589-1
:2015 –
“On
-land”
pip
elin
es,
dependin
g o
n s
ubstr
ate
,
corr
osio
n p
ote
ntial, t
em
pera
ture
, and e
nvironm
enta
l conditio
ns,
e.g
.:
Carb
on s
teel (g
enera
l) ≥
-0.8
5 V
to -
1.2
0 V
vs C
SE
Carb
on s
teel, u
nder
MIC
conditio
ns ≥
-0.9
5 V
to -
1.2
0 V
vs C
SE
Galv
aniz
ed s
teel -1
.20 V
vs C
SE
Cath
od
ic p
rote
cti
on
- o
pera
tio
nal re
co
mm
en
dati
on
s (
2)
!.".#:$$$%&'&=()×*×+×, -/and$,-=0123 -'
Tota
l curr
ent
dem
and c
an b
e c
alc
ula
ted b
ased o
n c
oating b
reakdow
n f
acto
rs
(8.4
.2),
or
based o
n c
urr
ent
density v
alu
es f
or
coate
d p
ipes (
8.4
.3)
ISO
15589-1
:2015 –
Desig
n c
urr
en
t d
en
sit
y
I tot!
: !Tota
l curr
ent
dem
and (
mA
)
4D×L!:!
Pip
e s
urf
ace a
rea (
m²)
k!
:!C
ontingency f
acto
r due t
o p
ossib
le n
on
-uniform
curr
ent
dis
trib
ution a
long t
he p
ipelin
e.
Usually
k >
1.2
5
J c!
:!T
ypic
al desig
n c
urr
ent
density f
or
coate
d p
ipe
5E!
:!P
ote
ntial shift
due t
o C
P c
urr
ent
measure
d a
gain
st
a
rem
ote
refe
rence e
lectr
ode (
mV
)
r co*!
:!A
vera
ge c
oating r
esis
tance (
Ω.m
²)
* S
pecific
ele
ctr
ical in
sula
tion r
esis
tance R
s1
00 a
s d
escribed in
ØIS
O 2
1809-3
“F
ield
join
t coatings”
ØIS
O D
IS 2
1809-1
1 “
Coatings f
or
in-f
ield
applic
ation,
coating r
epairs a
nd
rehabili
tation.”
-
Cath
od
ic p
rote
cti
on
- o
pera
tio
nal re
co
mm
en
dati
on
s (
3)
ISO
15589-1
:2015 -
Curr
ent
densitie
s j
c f
or
pip
e c
oatings (
mA
/m²)
Pip
e c
oating
Optim
ized
desig
n
Conserv
ative
desig
n
3LP
E o
r 3LP
P
0.0
01 t
o 0
.02
0.0
5 t
o 0
.2
FB
E0.0
2 t
o 0
.2
0.4
to 0
.7
Coal ta
r or
Bitum
inous
0.2
to 0
.3
0.3
to 0
.8
Note
s:
ØF
igure
s b
ased o
n e
xperience f
rom
diffe
rent
opera
tors
ØO
ptim
ized d
esig
n:
optim
istic b
ut
realis
tic d
am
age c
onditio
ns,
shall
be u
sed f
or
the d
esig
n o
f galv
anic
anodes
ØC
onserv
ative d
esig
n:
pessim
istic d
am
age c
onditio
ns,
should
be
used f
or
the d
esig
n o
f im
pre
ssed c
urr
ent
syste
ms
ISO
15589-1
:2015 –
Desig
n c
urr
en
t d
en
sit
y
When h
isto
rical data
for
a c
ert
ain
type o
f coating is n
ot
availa
ble
,
Specific
Ele
ctr
ical In
sula
tion R
esis
tance R
s1
00 g
ives a
good indic
ation
for
initia
l curr
ent
density.
12
– P
oly
meric t
apes
14
– H
eat
shrinkable
mate
rials
15
– H
ot
applie
d m
icro
cry
sta
lline w
ax
16
– E
lasto
meric c
oatings
17
– F
usio
n B
onded E
poxy (
FB
E)
19
– H
ot
applie
d P
E/P
P (
flam
e s
pra
y, s
heets
,
tapes,
inje
ction m
ould
ed)
Cath
od
ic p
rote
cti
on
– c
oati
ng
resis
tan
ce (
1)
ISO
21809-3
:2016 –
Sp
ecif
ic E
lectr
ical
Insu
lati
on
Resis
tan
ce R
s1
00
* W
hen R
s7
0≤ 1
0 X
Rs
10
0 then R
s1
00
/R
s7
0≥ 0
.8
Requirem
ents
for
Rs
10
0 o
f field
join
t coatings (
Ω.m
²),
and d
erived
curr
ent
densitie
s
(ΔE
= 1
000 m
V)
Coating t
ype
Rs
10
0*
Calc
ula
ted
j c (
mA
/m²)
11A
/B -
Petr
ola
tum
and w
ax t
apes
18A
/B -
Liq
uid
epoxy,
Liq
uid
poly
ure
thane
18C
/D -
Fib
re-r
ein
forc
ed e
poxy a
nd v
inyle
ste
r
≥10E
+6
0.0
01
13A
/B -
Non-c
rysta
lline low
-vis
cosity p
oly
ole
fin
≥10E
+8
0.0
00 0
1
-
Cath
od
ic p
rote
cti
on
– c
oati
ng
resis
tan
ce (
2)
ISO
21809-3
:2016 –
Testi
ng
Rs
10
0
Coated pipe
R=
1M
Ω
2 m
V
DC
po
wer
su
pp
ly ≥
50V
Test vessel
Hig
h-o
hm
ic
mil
livo
lt m
ete
r
Cath
od
ic p
rote
cti
on
– c
oati
ng
resis
tan
ce (
3)
ISO
21809-3
:2016 –
Testi
ng
Rs
10
0
67=
89;;<
8>?972@AAA
×B
8>?972@AAA26
Rs
:S
pecific
ele
ctr
ical in
sula
tion r
esis
tance (
Ω.m
²)
Vapp
:A
pplie
d p
ote
ntial (V
)
Vm
eas
:M
easure
d v
oltage d
rop a
cro
ss r
esis
tor
(mV
)
A:
Effective c
oating a
rea s
ubje
cte
d t
o t
est (m
²)
R:
Resis
tor
valu
e (
Ω)
-
Cath
od
ic p
rote
cti
on
– c
oati
ng
resis
tan
ce (
4)
ISO
21809-3
:2016 –
Sp
ecif
ic E
lectr
ical
Insu
lati
on
Resis
tan
ce R
s1
00
Reco
mm
en
dati
on
s:
ØR
s1
00 m
eth
od g
ives indic
ation o
f in
itia
l th
eore
tical curr
ent
density
only
.
ØIt
does n
ot
pre
dic
t lo
ng t
erm
coating p
erf
orm
ance a
nd c
oating
bre
akdow
n o
ver
com
mon p
ipe life c
ycle
s.
ØIt
is r
ecom
mendable
to inclu
de a
n a
ccele
rate
d c
oating a
gein
g
test fo
llow
ed b
y r
esis
tance m
easure
ment.
ØIS
O21809-3
:2016 s
pecifie
s r
equirem
ents
for
few
types o
f coatings
only
.
ØIt
is r
ecom
mendable
to inclu
de R
s1
00 r
equirem
ents
for
oth
er
types o
f coatings a
lso.
Cath
od
ic p
rote
cti
on
- D
isb
on
dm
en
t o
f co
ati
ng
s (
1)
2H
2O
+ 2
e-→
2O
H- +
H2
(g)
2O
H-
H2
(g)
ØpH
rais
es t
o 1
0 –
12:
§C
hem
ical att
ack o
n a
dhesiv
e /
coating
§C
hange in c
om
positio
n
§Loss o
f essential pro
pert
ies lik
e a
dhesio
n
ØG
as f
orm
ation u
nder
edge o
f coating:
§Lifting o
f coating
Fe
2e
-
I CP
2H
2O
CP
curr
ent
has d
irect
path
wa
y t
o b
are
ste
el
Colo
ur
inte
nsity
indic
ate
s p
H g
radie
nt
-
Cath
od
ic p
rote
cti
on
- D
isb
on
dm
en
t o
f co
ati
ng
s (
2)
Fe
I CP
Co
ati
ng
Dis
bo
nd
men
t an
d L
ifti
ng
fro
m
su
bstr
ate
Coating d
isbondm
ent
pro
gre
sses w
ith t
ime
Ele
ctr
oly
te w
ith
hig
h p
H
is d
raw
n u
nd
ern
eath
dis
bo
nd
ed
co
ati
ng
“C
ath
od
ic D
isb
on
dm
en
t”
Cath
od
ic p
rote
cti
on
- D
isb
on
dm
en
t o
f co
ati
ng
s (
3)
Fe
I CP
Acti
vati
on
p
ola
rizati
on
Fe←
Fe
2+
+2e
-
Co
nvecti
on
blo
ckin
g, h
en
ce
co
ncen
trati
on
po
lari
zati
on
Fu
lly p
rote
cte
d d
esp
ite c
oati
ng
dis
bo
nd
men
t
Co
ati
ng
D
isb
on
dm
en
t
The c
ritical curr
ent
density in c
ase o
f convection b
lockin
g r
equire
d f
or
passiv
ation is 1
mA
/m²
bare
ste
el. (
CeoC
or
2014: M
. B
uechle
r, S
GK
, S
witzerland,)
Pro
tection o
f dis
bonded a
rea
-
Cath
od
ic d
isb
on
dm
en
t – F
ield
exp
eri
en
ce
Possib
le c
auses:
Induced m
echanic
al dam
age t
hat
was w
ell-
pro
tecte
d b
y C
P.
Cath
odic
dis
bondm
ent
over
a larg
e a
rea b
ut
no
co
rro
sio
n w
as f
ou
nd
Dis
bondm
ent
of
3LP
E p
lant
applie
d c
oating
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(1)
A p
ara
mount
perf
orm
ance p
ara
mete
r accord
ing t
o s
om
e …
Sta
nd
ard
Po
ten
tia
l (V
)D
efe
ct
ØTe
mp
.E
lec
tro
lyte
D
ura
tio
nR
eq
uir
em
en
t
AS
TM
-G8
-1.4
5 t
o -
1.5
5 v
s C
SE
1/4
”2
3oC
Tri
ple
sa
lt 1
)3
0d
2)
No
ne
(te
st
meth
od
on
ly)
AS
TM
-G4
2-1
.53
vs
CS
E a
t 6
0oC
-1
.46
vs
SC
E a
t 6
0oC
1/4
”M
ax
. 6
0oC
Tri
ple
sa
lt 1
)3
0d
2)
No
ne
(te
st
meth
od
on
ly)
AS
TM
-G9
5-3
.00
vs
CS
E
-3.0
7 v
s S
CE
1
/8”
23
oC
3%
NaC
l9
0d
No
ne
(te
st
meth
od
on
ly)
AS
43
52
Req
uir
ed
cu
rre
nt
3 m
A
Mo
nit
ori
ng
po
ten
tia
l vs
SC
E6
mm
22
.5oC
3%
NaC
l
28
dA
:≤ 1
0m
m
B:
≤ 1
5m
m
C:
≤ 2
0m
m
D,
E:
≥ 2
0m
m
65
oC
24
h / 2
8d
95
oC
24
h
CS
A Z
-24
5.3
0
(FC
4)
-1.5
vs
SC
E
1/4
”2
0oC
3
% N
aC
l2
8 d
≤ 1
2 m
m
Tm
ax
By a
gre
em
en
t
EN
12
068
-1.3
8 v
s A
g/A
gC
l/s
at
KC
l-1
.39
vs
Ag
/Ag
Cl/
3M
KC
l
-1.4
2 v
s S
CE
-1.5
0 v
s C
SE
6m
m
23
oC
3%
NaC
l2
8d
A,
B,
C(H
T)
≤ 2
0m
mC
30
≤ 1
0m
mC
50
≤ 1
5m
mT
ma
x. 5
0oC
By a
gre
em
en
t
ISO
21
80
9-3
typ
e 1
2
-1.2
6 v
s S
HE
-1.5
0 v
s S
CE
6
mm
2
3oC
3%
NaC
l2
8d
≤ 1
5m
m
Tm
ax
. 9
5oC
By a
gre
em
en
t
1) 1
% N
aC
l +
1%
Na
2S
O4 +
1%
Na
2C
O3
2) O
pti
on
all
y l
on
ge
r b
y a
gre
em
en
t
SC
E =
Sa
tura
ted
Calo
me
l E
lec
tro
de
CS
E =
Sa
tura
ted
Co
pp
er/
Co
pp
er
Su
lph
ate
Ele
ctr
od
e
SH
E =
Sta
nd
ard
Hyd
rog
en
Ele
ctr
od
e
-
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(2)
2O
H-
H2(g
)
2e
-
I cd
t
2H
2O
+ 2
e-→
2O
H- +
H2(g
)
An
od
e
Ref.
El.
C
hlo
rine g
as (
Cl 2
) is
form
ed a
t anode. T
his
substa
nce r
eacts
with
hydro
xyl-
ions t
o f
orm
hypochlo
rite
, w
hic
h is t
he
active s
ubsta
nce p
resent
in e
.g.
ble
ach
An
accele
rate
d t
est
for
resis
tan
ce t
o h
igh
pH
an
d t
o C
hlo
rin
e:
Chlo
rine a
nd H
ypochlo
rite
are
know
n f
or
havin
g s
trong o
xid
ative
pro
pert
ies t
o o
rganic
substa
nces.
Art
ific
ial
co
ati
ng
defe
ct
Ø
6m
m / ¼
”
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(3)
Som
e t
ypic
al te
st setu
ps
ISO
21
80
9-3
:2016
AS
TM
G8
AS
TM
G4
2
AS
TM
G9
5
AS
43
52 (
B)
Use o
f P
ote
ntiosta
t
recom
mended
Use o
f “isola
ted”
anode r
equired;
pre
vents
diffu
sio
n o
f
chlo
rine into
bulk
of
ele
ctr
oly
te
-
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(4)
Inspection o
f coating d
isbondm
ent
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(5)
DIN
30670:2
012 -
A d
iffe
ren
t sta
nd
po
int
for
PE
pla
nt
co
ati
ng
s
Sco
pe:
facto
ry-a
pplie
d 3
LP
E
one-
or
multi-la
yere
d s
inte
red P
E.
Fo
rew
ord
:D
isbondm
ent
of
dam
aged p
oly
eth
yle
ne c
oatings involv
es n
eit
her
an
in
cre
ased
ri
sk o
f co
rro
sio
n (
under-
rusting)
no
r an
in
cre
ase i
n t
he p
rote
cti
ve c
urr
en
t
den
sit
y r
eq
uir
em
en
t in
cath
odic
corr
osio
n p
rote
ction.
The c
ath
odic
dis
bondm
ent
test th
us d
oes n
ot
serv
e t
o e
valu
ate
the b
oundary
phase
reaction in t
he c
ase o
f dam
aged c
oatings,
whic
h is u
navoid
able
in p
ractice,
but
is
prim
arily
a m
eans o
f assessin
g t
he b
oundary
are
as b
etw
een t
he e
poxy r
esin
layer
and t
he s
teel substr
ate
.
This
test has t
here
fore
been s
pecifie
d h
ere
to e
valu
ate
surf
ace
pre
para
tion.
For
sin
gle
-layer
sin
tere
d p
oly
eth
yle
ne c
oatings,
it is d
ifficult t
o a
chie
ve t
he r
equired p
eel
str
ength
without
suitable
surf
ace p
repara
tion,
and s
o t
he c
ath
odic
dis
bondm
ent
test
is n
ot
required f
or
sin
gle
-layer
sin
tere
d p
oly
eth
yle
ne c
oatin
gs.
-
Cath
od
ic d
isb
on
dm
en
t te
sti
ng
(6)
Co
nclu
sio
ns a
nd
Reco
mm
en
dati
on
s:
Many t
est
meth
ods e
xis
t but
results c
annot
mutu
ally
be c
om
pare
d !
Harm
oniz
ation is h
ighly
recom
mendable
because t
here
is m
any v
ariation
in t
est
conditio
ns,
a.o
.:
ØR
efe
rence e
lectr
odes a
nd t
est
pote
ntials
ØTest dura
tions
ØTest te
mpera
ture
s
ØU
se o
f is
ola
ted a
nodes t
o p
revent
exposure
to c
hlo
rine
ØU
se o
f pote
ntiosta
t fo
r contr
ol and loggin
g o
f curr
ents
and p
ote
ntials
Many t
ypes o
f coating d
isbondm
ent
exis
t, c
ath
odic
dis
bondm
ent
is just
one o
f th
em
.
Oth
er
cau
ses o
f co
ati
ng
dis
bo
nd
men
t Labora
tory
tests
– a
dhesio
n a
fter
accele
rate
d a
gein
g b
y h
ot
wate
r im
mers
ion
3-l
ayer
Poly
pro
pyle
ne @
95°C
2-layer
Poly
eth
yle
ne @
60°C
Heat-
shrinkable
sle
eve @
80°C
FB
E @
95°C
Adhesio
n s
trength
•In
itia
l: 1
00%
•60 d
ays:
7%
•120 d
ays:
0%
Adhesio
n s
trength
•In
itia
l: 1
00%
•60 d
ays:
0%
•120 d
ays:
0%
Adhesio
n s
trength
•In
itia
l: 1
00%
•60 d
ays:
124%
•120 d
ays:
56%
Adhesio
n s
trength
•In
itia
l: 1
00%
•60 d
ays:
40%
•120 d
ays:
29%
-
Cath
od
ic P
rote
cti
on
- a
safe
gu
ard
in
all
cases
? (
1)
Many t
ypes o
f coating d
am
ages
Cath
od
ic P
rote
cti
on
- a
safe
gu
ard
in
all
cases?
(2)
Vary
ing e
nvironm
ents
-
Cath
od
ic P
rote
cti
on
- a
safe
gu
ard
in
all
cases?
(3)
Cath
od
ic P
rote
cti
on
is a
ris
k-b
ased
tech
no
log
y*
ØV
ariation in s
oil-
resis
tivity
ØD
C s
tray c
urr
ents
ØT
idal are
as
ØA
C c
urr
ent
corr
osio
n
ØA
dja
cent
str
uctu
res o
r obje
cts
ØS
ulp
hate
Reducin
g B
acte
ria
ØH
igh o
pera
tional te
mpera
ture
s
ØB
ackfill
void
s
*C
eoC
or
confe
rence 2
015: B
. M
art
in, B
rian M
art
in &
Associa
tes, A
ustr
alia
A c
oati
ng
th
at
pro
vid
es e
xcell
en
t lo
ng
term
co
rro
sio
n p
rote
cti
on
is h
igh
ly r
eco
mm
en
dab
le.
Sto
paq
Co
ati
ng
Syste
ms
C
onsis
ts o
f at
least
2m
ate
rials
with d
iffe
rent
functions:
•C
orr
osio
n p
revention:
Sto
paq W
rappin
gband b
ased o
n p
ure
hom
opoly
mer
Poly
isobute
ne (
PIB
)
•M
echanic
al pro
tection:
Sto
paq O
ute
rwra
p p
oly
meric t
ape,
heat
shrinkable
sle
eve,
etc
.
-
Pro
pert
ies o
f p
ure
ho
mo
po
lym
er
Po
lyis
ob
uty
len
e (
PIB
)
MM
range:
n=
180 -
1400
ØLiq
uid
with low
gla
ss t
ransitio
n
tem
pera
ture
of
-67°C
:
üC
old
flo
w p
ropert
ies,
beneficia
l fo
r
100%
covera
ge.
üLiq
uid
, th
ere
fore
unable
to b
uilt
-up
inte
rnal str
esses.
ØV
ery
low
perm
eabili
ty f
or
wate
r vapour
and o
xygen:
üB
eneficia
l fo
r corr
osio
n p
revention.
ØN
o s
ensitiv
e c
hem
ical gro
ups:
üG
ood c
hem
ical re
sis
tance.
üR
esis
tance t
o a
gein
g a
nd w
eath
ering.
ØA
dhesio
n b
ased o
n v
anderW
aals
forc
es:
üS
urf
ace p
repara
tion n
ot
critical fo
r pro
per
bondin
g
üH
igh t
ack a
nd e
xcelle
nt
adhesio
n t
o v
arious s
ubstr
ate
s lik
e s
teel, P
E,
PP,
FB
E,
de-r
uste
d s
teel, n
eopre
ne e
tc.
Self
-heali
ng
of
Co
ati
ng
s b
ased
on
pu
re h
om
op
oly
mer
PIB
(1)
P
1)
Tensio
nle
ss a
pplic
ation o
f
pure
hom
opoly
mer
PIB
based c
om
pound layer
2)
Applic
ation o
f P
oly
meric
Oute
rwra
p w
ith
tensio
n
-
Self
-heali
ng
of
Co
ati
ng
s b
ased
on
pu
re h
om
op
oly
mer
PIB
(2)
1.
Dam
age induced t
o the c
oating (
Ø 6
mm
)
2.
Fle
xib
le m
echanic
al O
ute
rwra
p e
xert
s p
ressure
to the p
ure
hom
opoly
mer
PIB
based c
om
pound layer
3.
Com
pound f
low
s t
ow
ard
s t
he d
am
age a
nd s
eals
the s
teel fr
om
the
environm
ent.
When s
elf-h
eale
d,
it s
tops f
low
ing.
Self
-heali
ng
of
Co
ati
ng
s b
ased
on
pu
re h
om
op
oly
mer
PIB
(3)
-
CD
-test
of
Co
ati
ng
s b
ased
on
pu
re h
om
op
oly
mer
PIB
Cath
od
ic d
isb
on
dm
en
t re
sis
tan
ce a
cc.
ISO
21809-3
:2016
•@
+ 2
3OC
and +
70
OC
(=T
max)
for
28 d
ays @
-1500 m
V
Cath
od
ic d
isb
on
dm
en
t re
sis
tan
ce a
cc. A
ST
M G
42:
•@
+ 6
5OC
for
90 d
ays @
-3000
mV
Resu
lts o
f all
tests
:
•D
isbondm
ent
0 m
m (
or
actu
ally
-3 m
m)
•N
o h
olid
ays
•S
elf-h
ealin
g c
om
ple
ted w
ithin
24 h
ours
.
Acce
lera
ted
ag
ein
g t
es
t C
oati
ng
s b
as
ed
on
pu
re h
om
op
oly
me
r P
IB
Peel
tests
aft
er
Th
erm
al A
gein
g a
nd
H
ot
Wate
r Im
mers
ion
fo
r 100 d
ays @
T
max+
20°C
No c
hange in c
oating p
erf
orm
ance
aft
er
accele
rate
d a
gein
g t
ests
:
üP
eel str
ength
valu
es ≥
0.2
N/m
m @
23°C
üP
eel str
ength
valu
es ≥
0.0
2 N
/mm
@T
max
üC
ohesiv
e f
ailu
re
üC
overa
ge ≥
99%
-
Resis
tan
ce R
s1
00 o
f p
ure
ho
mo
po
lym
er
PIB
-based
co
ati
ng
Rs
70: 1.6
E+
10 Ω
.m²
Rs
10
0: 8.1
E+
09 Ω
.m²
Co
nclu
sio
ns
ØC
orr
osio
n o
f pip
elin
es is a
ris
k, cath
odic
dis
bondm
ent
of
coatin
gs is n
ot!
ØA
sset
ow
ners
should
focus m
ore
on c
oatings t
hat
have g
ood long t
erm
perf
orm
ance p
ropert
ies w
hic
h c
an b
e e
valu
ate
d b
y e
.g.
accele
rate
d a
gein
g
tests
.
ØC
oatings b
ased o
n p
ure
hom
opoly
mer
Poly
isobute
ne m
eet
or
even e
xceed
exis
ting p
erf
orm
ance r
equirem
ents
:
ØH
igh
Specific
Ele
ctr
ical In
sula
tion R
esis
tance
ØS
elf-h
ealin
g o
f sm
all
co
ating d
efe
cts
ØC
ath
odic
Dis
bondm
ent te
sts
result in 0
mm
dis
bondm
ent and n
o
holid
ays
ØE
xce
llent lo
ng term
re
sis
tance to a
gein
g in d
ry a
nd w
et co
nd
itio
ns
at m
axim
um
desin
g tem
pera
ture
