Download - Th0800Coll Corrosive Technologies
-
8/12/2019 Th0800Coll Corrosive Technologies
1/35
Corrpro. All Rights Reserved.
Corrosion Technologies to Assessthe Condition of Force Mains
James T LaryCorrpro
1055 W Smith RoadMedina, OH 44256Tel: 330-723-5082
Email: [email protected]
-
8/12/2019 Th0800Coll Corrosive Technologies
2/35
Corrpro. All Rights Reserved. 2
Practical
Tendency of a Metal to Revert
to its Native State
Scientific
Electrochemical Degradation
of Metal as a Result of a Reaction
with its Environment
Corro sion Can be Defined as Either:
-
8/12/2019 Th0800Coll Corrosive Technologies
3/35
Corrpro. All Rights Reserved. 3
IRON OXIDE REFINING MILLING
IRON,STEEL,PCCP CORROSION IRON OXIDE
Corrosion Process
-
8/12/2019 Th0800Coll Corrosive Technologies
4/35
Corrpro. All Rights Reserved. 4
External Corrosion Attack
-
8/12/2019 Th0800Coll Corrosive Technologies
5/35
Corrpro. All Rights Reserved. 5
Temporary Fix ?
-
8/12/2019 Th0800Coll Corrosive Technologies
6/35
Corrpro. All Rights Reserved. 6
Anodic Area
Internal & External Corro sion
of Force Mains.
Solids
Buildup
H2S
-
8/12/2019 Th0800Coll Corrosive Technologies
7/35 Corrpro. All Rights Reserved. 7
24 DIP
Multiple failures onbottom of pipe
Performed ultrasonic
thickness measurements
Scouring and turbulentflow contributed to failure
-
8/12/2019 Th0800Coll Corrosive Technologies
8/35 Corrpro. All Rights Reserved. 8
24 Ductile Iron Force Main
Internal failure following
loss of internal mortar
lining
Failure was along top ofpipe due to formation of
hydrogen sulfide gas
-
8/12/2019 Th0800Coll Corrosive Technologies
9/35 Corrpro. All Rights Reserved. 9
24 DIP & Steel
Internal pipe failuresalong crown of pipe
Failures following loss of
internal mortar lining
Cause is formation ofhydrogen sulfide gas
-
8/12/2019 Th0800Coll Corrosive Technologies
10/35 Corrpro. All Rights Reserved. 10
Dual 26 Force Mains
Internal failures at
bottom of pipe
Failure following loss of
internal mortar lining
Failures concentrated at
low areas (dips) in
pipeline alignment
Cause is corrosion under
accumulated solids
-
8/12/2019 Th0800Coll Corrosive Technologies
11/35 Corrpro. All Rights Reserved. 11
36 Above Ground Crossing
Failure of force mainat above ground crossing
Crown of pipe attacked
by hydrogen sulfide gas also
external corrosion of pipe
-
8/12/2019 Th0800Coll Corrosive Technologies
12/35 Corrpro. All Rights Reserved. 12
History of Iron Pipe
Cast Iron
- Introduced to North America during the 1800s and
installed till the 1970s.
- Early on, statically cast process produced a thick
walled, heavy pipe.
- No longer produced in North America.
Ductile Iron
- Introduced in 1955 as an
improvement to cast iron.
- Centrifugal castingprocess produces a thinner
walled, lighter pipe which is
stronger and more ductile
than cast iron.
-
8/12/2019 Th0800Coll Corrosive Technologies
13/35
Corrpro. All Rights Reserved. 13
Actual size of AWWA Specification Thickness Reductions
for 36-inch Diameter Cast and Ductile Iron Pipe - 1908 to Present
(150 PSI Operating pressure)
1.58 in.
1908 1952 1957 1957 1976 1985 1991 Less
CLD CL 150 CL 23 CL 22 CL 3 CL 50 CL 150 Tolerances
CI CI 18/40 21/45 DI DI DI
CI CI
1.22 in.
0.94 in.
0.87 in.
0.58 in. 0.43 in.0.38 in.
0.21 in.
-
8/12/2019 Th0800Coll Corrosive Technologies
14/35
Corrpro. All Rights Reserved. 14
Cast (Grey) Iron
Failures
Cast Iron Pipe
(thicker walled pipe)
-
8/12/2019 Th0800Coll Corrosive Technologies
15/35
Corrpro. All Rights Reserved. 15
Ductile Iron
External pitting
(concentrated) corrosion
attack on thinner walled
ductile iron pipe.
-
8/12/2019 Th0800Coll Corrosive Technologies
16/35
Corrpro. All Rights Reserved. 16
Adverse Cond it ion s fo r Metal l ic Pipe
- High Chlor ides- Low Soi l /Water Resist iv i ty
- High Sulfates
- Acidic Soi ls
- Wet/Dry Fluctuations
- Bimetall ic Coupl ings
- Stray Current Interference
-
8/12/2019 Th0800Coll Corrosive Technologies
17/35
Corrpro. All Rights Reserved. 17
Stray Currents
Underground Gas &
Oil Piping AC Transmission Lines
-
8/12/2019 Th0800Coll Corrosive Technologies
18/35
Corrpro. All Rights Reserved.
Pipe
Metallic Coupling
Lower Stress Area(Cathode)
Threaded Bolt
Higher Stress Area
(Anode)
Stress Corrosion
-
8/12/2019 Th0800Coll Corrosive Technologies
19/35
Corrpro. All Rights Reserved. 19
The rate and magnitude of corrosion depends
on a number of factors:
Pipe Material and Characteristics
Operating Conditions
Construction Methods
Environment (age not a good primary metric)
Internal / External Corrosion Attack
-
8/12/2019 Th0800Coll Corrosive Technologies
20/35
Corrpro. All Rights Reserved. 20
#2Indirect Inspection
#3Direct Examination
#1Pre Assessment
#4Post Assessment
Initial development driven
by federally regulated
pipeline integrity rules
Methodology also quite
applicable to water /
wastewater
Pipeline Condi t ion Assessment Process
-
8/12/2019 Th0800Coll Corrosive Technologies
21/35
Corrpro. All Rights Reserved. 21
#1 Pre-Assessment:
Define pipe segments by
construction contracts and similar
characteristics, e.g. material,
construction practices
Identify specific locations along
the pipeline
Air Release Points/Man ways Pipeline crossings
Known area where piping
failures have occurred
-
8/12/2019 Th0800Coll Corrosive Technologies
22/35
Corrpro. All Rights Reserved. 22
Good listening operating history,criticality, consequences of failure
Leak & Repair Records
Pipe Bone Yard
Coordination of ConditionAssessment Efforts With OtherActivities Excavations
Repairs
Project construction drawings andspecifications (High and low points)
Pipe materials and characteristics Wall thickness
Pressure rating
Flow Rates
Air Release points/operational status Coatings and Linings
Bedding and backfill material
As-built documentation
Soil corrosivity, e.g. resistivity, pH,chlorides, moisture
Adjacent utilities and crossings
Sources of stray current corrosion Nearby cathodic protection systems
Direct current powered transit systems
High voltage overhead AC power lines
#1 -Pre-Assessm ent Data Gathering & Plann ing :
-
8/12/2019 Th0800Coll Corrosive Technologies
23/35
Corrpro. All Rights Reserved. 23
Indirect Inspection techniques:
In-Situ Soil Resistivity Measurements
Soil Sample Collection and Analysis
Ultrasonic Thickness Measurements (air releasevalves or accessible points)
Direct Examination of Exposed Pipe Sections
Stray Current Evaluations
#2 - Ind irect Inspec tion :
-
8/12/2019 Th0800Coll Corrosive Technologies
24/35
Corrpro. All Rights Reserved. 24
#2 - Ind irect Inspec tion :
Integrate all data along pipeline alignment
Analyze Data and Rank Indications: Severe Moderate
Minor
Select at sites for direct inspectionlocations shouldbe where corrosion activity is most likely
Select control site where corrosion activity is the leastlikely
-
8/12/2019 Th0800Coll Corrosive Technologies
25/35
Corrpro. All Rights Reserved. 25
#3 - Direc t Exam ination
Excavating the pipe
Performing physical
inspection & photograph
Evaluating integrity of
coating/wrap, if present
Testing the pipe surface,e.g. corrosion pitting
UT measurements
Measuring dimensions of
corrosion defects
Analyzing surrounding soil/ groundwater
Internal video/inspection
-
8/12/2019 Th0800Coll Corrosive Technologies
26/35
Corrpro. All Rights Reserved. 26
Inspector name_________ Date____ Address of pipeline inspection ________________ Leak? Yes____ No____ File Number:_____________
1) Type of Pipe: cast iron_____ ductile iron____ carbon steel___ copper______ carbon steel_____ non metallic_____ concrete________other____
2) Diameter of pipe _____ Pipeline Name_________ Service Type: Water____ Wastewater____ Estimated date of pipe installation______ Depth of pipe______3) Type of Pipe: Distribution____ Transmission____ Service_____ Hydrant _____ Mechanical joint_____ Fasteners____ _ Other____ Unknown____
4) Type of Coating: Polyethylene Encased____ Shop applied coating___ No Coating____ Tape Wrap____ Unable to determine____
5) External Pipe Condition: Very Good____ Good____ Poor____ comments:____________________________________________________________________
___________________________________________________________________________________________________________________________________________
6) Ultrasonic Thickness Measurements and comment______________________________ Internal Lining Present _____ Yes ____No comment_________________
6) Is corrosion pitting evident? ____ Yes ____ No Number of Pits______ Typical Size of Pits______ Quantity of pits:______
7) Is graphitization evident (longitudinal or circumferential breaks) ____Yes ____ No
8) Is the pipe installed in (check off appropriate items): Industrial area____ Residential area____ Rural area____ Near street or road ____Near creek or waterway ____ In reclaimed land___ Near oil or gas pipelines____ Near high voltage lines ____.
8) Describe soil conditions where inspection occurred: wet____ dry____ clay soil ____ rocky soil____ cinders ____ other____________________
9) Where soil samples obtained, sealed and analyzed for chlorides, moisture content, pH, sulfides, resistivity? If yes resul ts were: _____________________________
10) Were previous repairs made on the pipeline (leak clamps, etc) Yes____ No ____. Was new pipe installed____ Yes ____ No.
11) Was a repair clamp installed on the pipe during inspection ___ Yes ___ No
12) Was a galvanic anode installed as part of the inspection process? ___ Yes ___ No, if yes size and quantity
13) Please relay additional comments:
_____________________________________________________________________________________________________________________________________
__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
14) Plan of Action____________________________
15) Insert digital photos below:
Force Main Pipeline Inspection Report
-
8/12/2019 Th0800Coll Corrosive Technologies
27/35
Corrpro. All Rights Reserved. 27
#3 - Direc tExaminat ion:
When corrosion is found, perform
a root cause analysis
Implement localized corrosion
protection
Install instrumented test station
for future assessment of
corrosion activity, e.g. corrosion
rate probes
-
8/12/2019 Th0800Coll Corrosive Technologies
28/35
Corrpro. All Rights Reserved. 28
#4 Post Assessment:
Calculate remaining life
Pit growth rate and wallthickness
Internal or External Corrosion
Coupons
Electrical resistance (ER)probes
Maximize benefit by
Capture ideas for improvement
Determine need/timeframe forupdate evaluations
Identify corrective actionoptions
Probe-Tag: 5500 K11A-1
Probe Type: PA-0.4-10-0.1-6Probe serial No.: PA04270025
Test initiated: 20-12-2005
0
100
200
300
400
500
600
700
800
900
1000
1 7/03 /0 6 1 8/03 /0 6 1 9/03 /0 6 2 0/03 /0 6 2 1/03 /0 6 2 2/03 /0 6 2 3/03 /0 6 2 4/03 /0 6 2 5/03 /0 6
Date
AC
current-
A/m2
Corrosionratemicron/y
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
JDC
A/m2
Uac(V)
Corrosion rate Uac Jdc
-
8/12/2019 Th0800Coll Corrosive Technologies
29/35
Corrpro. All Rights Reserved. 29
#4 Post Assessment Recommendations:
Identify Corrective Options
Operational Procedures
Treatment Practices
Internal Lining
Cathodic Protection
Stray Current Mitigation Partial or Full Pipeline
Replacement
Pipeline Monitoring
-
8/12/2019 Th0800Coll Corrosive Technologies
30/35
Corrpro. All Rights Reserved. 30
Program fo r Exist ing MainsBreak Reduct ion L ife Extension Through Cathodic Protect ion
-
8/12/2019 Th0800Coll Corrosive Technologies
31/35
Corrpro. All Rights Reserved.
Pipe
Metallic Coupling
GalvanicAnode
Anode Lead Wire Connection
Cathodic Protection of Metallic Fitting
-
8/12/2019 Th0800Coll Corrosive Technologies
32/35
Corrpro. All Rights Reserved. 32
Meter Vaults
(Keep dry if possible)
-
8/12/2019 Th0800Coll Corrosive Technologies
33/35
Corrpro. All Rights Reserved. 33
Other Structures
-
8/12/2019 Th0800Coll Corrosive Technologies
34/35
Corrpro. All Rights Reserved. 34
Summary
Effective management of force mains pipeline includesunderstanding and managing the risk of corrosion
A systematic approach to condition assessments results
in the most value at the lowest cost
Retrofitting with accepted industry practice such as
internal linings, treatment programs, operational
adjustments, or cathodic protection may be a cost
effective options for extending the life of existing mains
A key asset management strategy is to include suitable
corrosion control in the design of new force mains
-
8/12/2019 Th0800Coll Corrosive Technologies
35/35
Thank You
James T Lary
(330) 241-6615