Presented on Monday, May 16, 2011 by: Gregg Crow Pipeline Composite Repair Presentation
Presented on Monday, May 16, 2011by: Gregg Crow
Pipeline Composite Repair Presentation
What is a Composite?
Two or more materials combined in such a way that the individual materials are easily distinguishable.
A common example of a composite is concrete. It consists of a binder (cement) and a reinforcement (gravel and rebar). Concrete is a three-phase composite.
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Composite repairs odd-
shape line quickly.
How long have composites been used?
1940’s – aerospace, military, marine, sporting goods, electronic industries and they appeared in the pipeline industry in late 1980s.
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Corroded bridge
column on DOT
highway
Wet-layup prepregnated
composite used for structural
reinforcement repair
Composite repair
completed
Does the DOT approve of pipeline composite repair technology?
• Prior to 2000, only ClockSpring’s rigid composite system was allowed through an issued waiver.
• Effective January 13, 2000, the DOT published
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within CFR 192.713 or 195.585 (Google it): “Repaired by a method that Reliable engineering tests and analyses show that can
permanently restore the serviceability of the pipe”.
(Therefore, any composite can be used if it has engineering testing like
ASME’s PCC-2, but not limited to, as PRCI, GRI, Battelle, SWRI and many others
listed on the next page have established composite testing criteria:)
ASME Post Construction Committee (PCC-2) – 16 composite testing criteria
ASME B31.4 & .8 – specifies composites can be used on <80% general corrosion
pitting, and on some dents, gouges, wrinkles, etc that are still piggable.
Note: NACE certification is not required to install a composite because they are not
considered a coating but a mechanical reinforcement repair. Though, most composite
manufacturers should require completion of their OQ install or train-the-trainer classes.
Composite Testing and Research
• ASME’s Post Construction Committee (PCC-2) established 16 composite repair engineering tests.
• Gas Research Institute (GRI)
• Southwest Research Institute (San Antonio,TX)
• Battelle Columbus Division (Columbus, Ohio)
• Kiefner & Associates, Inc.
• Stress Engineering
• Pipeline Research Council International (PRCI)
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Regulations don’t specify engineering testing entity
Why has the energy pipeline industry started using composites to reinforce hoop/pressure containing
strength on metal wall loss & mechanical damage?
• Alternative to repairing a pipeline with a welded
sleeve or cut-out. ASME recommends using only
<80% general corrosion pitting, and on some dents,
gouges, wrinkles, etc that are still piggable.
• In-service repair – don’t have to lower the
pressure to install.
• Faster to install – about 1/3 of the time compared
to a welded sleeve.
• Non-conductive to CP except carbon fiber
composites.
• Wet-layup composite systems are excellent for odd
shape pipeline sections – bends, elbows, tees,
weld-o-lets, etc.
• Often the most economical way to repair a
pipeline.
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Wet layup- spiral wrapped, cures
as one-solid-mass and can
backfill one hour later. Requires
no field mixing of resin into cloth
and no cinch bars or hammers.
Types of Composite Systems? Wet Layup –
field impregnatedRigid/Layerd/PreCuredWet Layup –
prepregnated
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Resin mixed into cloth
minutes prior to install
Apply right out of the bag Tightening it up Each layer must be mixed
with resin before applying
Elbow repair Resin applied between
each layer
Pipeline Composite Repair Materials?
• Fibers – E-glass, carbon, aramid(Unidirectional – hoop stress or biaxial woven – hoop & axial stress)
• Matrix – meaning resins: epoxy, polyester, vinyl ester, phenolicpolyurethane.
Fibers provide the reinforcement, like rebar and gravel do for concrete. The matrix, like cement used in concrete, is what holds the fibers/reinforcement in place and allows the transfer of the load/pressure throughout the fibers/reinforcement.
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Wet-layup prepreg – apply right out of
bag. Resin comes mixed into cloth
Have to mix resin into cloth in the
field. You don’t with wet-layup
prepreg.
Fiber Patterns
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Unidirectional – provides
hoop strength only
Biaxial Woven – provides
hoop and axial strength.
Which Composite is the strongest?
Most composites used in the energy pipeline market place have undergone 3rd-party engineering fatigue testing to prove they can last anywhere from 25-50 years as a permanent pipeline field repair. Ask the composite manufacturer for their engineering testing results; such as, ASME Post Construction Committee (PCC-2).
50% defect wrapped with wet-layup
prepreg and burst tested to failure. Good
section of pipe failed and wet-layup did
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What types of energy pipeline defects can be repaired with composites?
• External Corrosion – <80% wall loss on any shape of pipeline.
• Internal Corrosion – not recommended, because no way to seal off corrosive environment as on
external corrosion with 100% solids epoxy before reinforcing hoop strength with a composite.
• Dents or Gouges – if the pipeline is still piggable (recommended to grind gouges smooth)
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Pipeline defects repaired with composites
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Girt Weld Wrinkles on bend
Corrosion pitting, welding defects
Vertical – soil-to-air Weld-O-Let
Weld-o-let
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Soil-to-air composite repairs
Wet-layup prepregnated Soil to air interface corrosion repaired quickly 2”x10’ roll.
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Wet-layup the girth welds prior to bore, tested on pull head. :
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Before wrapped
Wrapped
After pulled through bore
Typically – powercrete epoxy
Wet-layup easily repairs odd-shape pipe.
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External Corrosion Load transfer epoxy filler/primer Composite 4” wide x 15’ long roll
installed right-out-of the bag. No
mixing of resin into cloth
required, minutes prior to install.
Composite’s resin is pre-
pregnated into cloth during its
manufacturing process. Also,
there are 2” and 3” wide rolls
ranging in lengths of 10’-30’.
Blue wrap and perforate Remove blue anytime after 45
minutes.
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Elbow repaired with composite
in less than one hour
Wet-layup ready to apply right
out of the bag, requires no
field-mixing of cloth with epoxy
resin minutes prior to install
Soil to air interface repair in one hour , 2”x10’
roll
44’ linear 10” pipe with 77% external corrosion
repaired with wet-layup, in one hour, to
reinforce hoop strength. No pressure reduction
& backfilled one hour later
Wet-layup Pipeline Repair Photos
Wet-layup Swamp Pipeline Repair
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Before repair lifted 8” pipe out of water 96’ repaired with composite in 3 hours, pipe lowered back into water same day
Swamp Pipeline Repair
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Removing old coating
Sandblasting
Corrosion pitting, wrapped with wet-layup
Wet-layup repair complete
Dehy44.5”OD wrapped with wet-
layup repair
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Pipe anomaly where support
bracket was cut off. Sand
blasted to achieve bare metal
and a good anchor pattern for
repair materials to adhere.
A butyl rubber patch was placed over
anomaly and adjacent leaking crack.
Leaks < 60 psi in-service or blown
down.
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Biaxial-woven fiberglass cloth was pregnated with a hydrocarbon
chemical resistance two-part epoxy then placed over the butyl
rubber tape patch to serve as a backup patch.
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Coat sand-blasted area with non-
permeable two-part epoxy.
Immediately after wrapping
composite around the pipe, apply 3
layers of the blue plastic then
perforate it so composite will displace
water and Co2, which is the bi-
product from the chemical reaction of
moisture and the factory prepreg
polyurethane resin in the composite.
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45 minutes later, remove blue plastic and the mechanical
reinforced composite is setup. It can be an in-service
repair on leaks up to < 60 psi.
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ExxonMobil 8” line underwater that was hit by an anchor in the Caribbean Sea, causing a dent gouge
ExxonMobil 8” line was repaired using composite in 2006
BP’s offshore platform had heat exchanger repaired using wet-layup prepreg composite in 2009
Chevron offshore platform in 2009 was repaired using wet-layup prepreg composite
Offshore composite repairs successfully completed using composite
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How long does it take to install a composite and then how long until it can be backfilled?
Wet Layup
field impregnated
Wet Layup
prepregnatedRigid/Layerd/Precured
Spiral or circumferentially
wrapped. Quickest to
install on any shape of
pipe: tee, elbow,
transition piping. Ready
to backfill 1 hour after
install.
Only circumferentially
wrapped. Takes longer to
install than wet-layup prepreg
because resin has to be
mixed into cloth. Must wait
several hours before
backfilling.
Only circumferentially
wrapped and limited to
straight pipe repairs. Takes
longer to install than both
wet-layups. Must wait a few
hours before backfilling.
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How many layers do I need to apply?
• Most composite manufacturers have a spread-sheet calculator that uses Barlow's formula, Rstreng and factors in the mechanical strength that each layer of their composite system provides, per their 3rd-party engineering testing results.
• Make sure their calculator factors in the degradation of their composite wrap’s materials. They might only need 4 layers today to contain your actual MOP, but 20 years from now that same material might only have 70% of its strength remaining.
• Most composite manufacturers have performed 3rd
party testing to determine the degradation of their composite wrap’s materials.
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How far past the defect must you wrap?
• ASME Post Construction Committee-2
formula:
Length of the defect plus
2 X 2.5 X SQRT of (OD X Wall Thickness )
2
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Are Composites Pig Detectable?
• Composite wraps are identifiable by a pig when placing a metal band around the end of each end of the composite wrap.
• Or, some operators place a washer under the last layer, and at the same orientation on the pipeline.
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Place metal bands around each
end of the repair so it will be
smart-pig detectable.
Do composites breach the CathodicProtection?
• Composites that adhere well to the pipeline’s surface provide a good barrier between the anomaly and corrosive environment, so no CP should be needed underneath the repair area.
• However, if the composite separates from the pipe allowing moisture/oxygen to channel underneath it, and the composite material is too resistant/dielectric to allow CP to push through it, then you will have CP Shielding.
• To prevent a corrosion cell, at least top-coat the ends of the composite repair with a non-permeable coating that will not allow moisture or oxygen to channel back underneath the sides of the composite, which would cause the anomaly to further corrode and eventually cause a leak underneath the composite repair.
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For steel substrates, it’s recommend cleaning to bare metal, NACE II or SSPC-10 level. The better the cleaning and preparation, the better the wrap will bond/adhere to the pipe. For concrete surfaces, above and below the water line, all loose debris, coatings, marine growth, etc. must be removed. This can be done with high pressure water blasting or sand blasting.
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Step 2: Fill all voids with 2-part load-transfer epoxy, and coat the entire area being wrapped.
Installation Process
Step 1: Sand Blast –NACE II Near White Finish. Or, at least don’t wrap over old coating and rough up surface to ensure anchor pattern.
Step 3 spiral wrapping technique installed quickly.
Step 5: Immediately after applying, wrap three layers of the plastic wrap over it tightly, and perforate it so excess water will drain out. 45 minutes later remove plastic then back fill.
Installation Process
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Step 6:45 minutes after install, now one solid layer and ready to backfill. Metal bands placed around the ends so it will be pig detectable.
What lengths and widths are available for each composite systems?
Wet Layup –
prepregnated
Wet Layup –
field impregnated
Rigid/Layerd/Full Cure -
Supplied in 2“,3" 4“, 5”, 6" , 8”,10“, 12" wide X 10’, 20’,
25’, 30’, 50’, 60’, 90’, 120’ long rolls and installed
continuously and can be circumferentially or spiral
wrapped.
Typically supplied in 12” wide
One roll of cloth for each layer must be wetted with
resin and installed separately and only
circumferentially wrapped.
Typically supplied in 12” wide
Have to apply resin between each layer and only
circumferentially wrapped.
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Cost comparison of composite systems used to repair pipelines:
Wet Layup –
prepregnated
Wet Layup –
field impregnated
Rigid/Layerd/Full Cure -
More expensive
Least expensive
Most expensive
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Factors to consider when choosing a composite:
• Engineering testing - 3rd-party engineering testing? DOT requires that composites
have “Reliable Engineering Testing” before being used on a regulated line.
• DOT regs and ASME Codes – read and understand them, don’t rely on composite
manufacturers.
• Type of defect – wet-layup will conform to both straight and odd shaped pipelines, and
the rigid/layer/pre-cured systems are typically limited to straight pipelines.
• Life of repair – how long do you need the repair to last? 25 year? 50 Years?
• Length of repair – how many linear/axial inches or feet do you need repaired? Wet
layup pre-pregnated systems come in many different widths so you only buy near the
exact amount of material needed. Field impregnated and rigid/layer/pre-cured systems
only come in 12” wide and often rigid systems require 8 layers when only 4 are needed.
• Costs – wet-layup systems are cheaper than rigid systems, especially pre-pregnated.
• Carbon wraps – don’t apply directly against the steel pipeline, because it’s more
positive than steel and will thus cause corrosion. Insulate with a two-part non-permeable
epoxy or a layer of fiberglass wrap before applying onto pipeline.
• CP shielding – how dielectric is the composite?
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Installation Procedure:
Step 1: Wear gloves and protective eye wear. Read MSDS!
Step 2: Drill 3/16” holes into sleeves to pour two-part epoxy resin.
Step 3: Pour .7 gallon of epoxy curing agent into the two-gallon container
already partially filled with 1.3 gallons of epoxy base agent.
Step 4: Mix epoxy for 2 minutes using a Home Depot battery drill with a paint
mixer drill bit.
Step 5: Pour mixed epoxy into the drilled-hole to fill annulus.
Description: Epoxy is 100% solids, low viscosity epoxy resin especially formulated for
maximum penetration into voids or porous surfaces. It is water tolerant and
able to displace water from wet surfaces to form a strong bond. Our epoxy is
NonHazmat for shipping without restrictions by air, sea or land. 2-4 hour cure
time depending on temperature. Seal welded with ½”plugs.
Materials Needed:
1) .7 gallon of epoxy curing agent supplied in one-gallon container.
2) 1.3 gallon of epoxy base agent supplied in two- gallon container.
3) Home Depot style battery drill with paint mixer drill bit.
4) 3/16” drill bit to drill and access the space between sleeve and pipe.
5) Wear protective gloves and glasses when handling epoxy.
Installation procedure for injecting
non-permeable two-part epoxy into
annulus of pumpkin sleeves:
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Thank You
Gregg Crow
Phone: 817-240-6434
Email: [email protected]: www.myoilpatch.com
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Pipeline Composite Repair Presentation