8/8/2019 3-LAYER Coating of Pipes

1/13

PRD CO., INC. .1321 W.WINTON AVE. HAYWARD CA . 94545 USA PH (510) 782 7242 . FAX (510) 887 5639

http://www.prdcompany.com e-mail:prdsales@prdcompany.com

3-LAYER

POLYETHYLENE

COATING SYSTEMS

WORLD LEADER IN LARGE DIAMETER PIPE MANUFACTURING

TECHNOLOGY

8/8/2019 3-LAYER Coating of Pipes

2/13

PRD

Pipe ManufactSystems

3-LAYER POLYETHYLENE COATING SYSTEMS

CONTENTS

A- COATING LAYERSB- TECHNICAL DATA OF THE PIPESC- COATING CAPACITYD- SYSTEM COMPONENTSE- COATING PROCESSF- PROCESS PARAMETERSG-PROCESSH-

TYPES OF WRAPPING

I- CAPACITIES OF THE MACHINES AND EQUIPMENTSJ- INSPECTIONS AND TESTSK- REPAIR

1

PE COATING PROCESSPE COATING PROCESSPE COATING PROCESSPE COATING PROCESS

8/8/2019 3-LAYER Coating of Pipes

3/13

A-COATING LAYERS

1- Fusion Bonded Epoxy ( Primer ) used for corrosion protection.2- Copolymer Film ( intermediate layer adhesive ) used for bonding between fusion bonded epoxy

layer and polyethylene layer.

3- Polyethylene Film ( top layer ) used for mechanical resistance to damages may arise in thehandling, transportation and laying of the pipe.

There are two main advantages of the coating by combination of multi-layers :

1- Excellent adhesion and chemical resistance properties obtained by fusion bondedepoxy ( first layer - corrosion protection ).

2- Strong physical and mechanical performance obtained by extruded adhesive copolymer( intermediate layer ) and polyethylene ( top layer ).

B-TECHNICAL DATA OF THE PIPES

Pipe Diameter : 200 mm 2500 mmWall Thickness : 3 mm 25 mmPipe Length : 6 16 m.

C-COATING CAPACITY250 m2 / hour ( optionally 400 m2 / hour )

INTRODUCTION :

Pacific Roller Die Co. Inc. supplies complete plants for polyethylene coating of pipes.PRDs technology provides pipe manufactures the best solution for their specific needs.PRD gives service to their customers from layout design to operation.

2

3-LAYER PE COATING :

3-Layer PE Coating provides high quality protection of steel line-pipes to be used fortransportation of natural gas, oil and water.

3-Layer PE Coating has great influence on the service life of pipeline.

8/8/2019 3-LAYER Coating of Pipes

4/13

D-SYSTEM COMPONENTS

1- Pipe Entry Racks - Let-Down Arms2- Pipe Conveyors for Cleaning ( Blast ) Line3- Flame Heating Furnace ( Preheating ) Natural Gas or LPG4- Grit/Shot Blast Cleaning Machine ( Roto-jet double disc turbines )5- Pipe Kick-Out Arms, Pipe Racks and Let-Down Arms6- Process Conveyors7- Induction Heating System ( High Voltage Generator and Induction Coil )8- Electrostatic Epoxy Powder Spraying Unit CO2 Fire Extinguishing System9- Adhesive Extruder and Side Wrapping Head

10- Adhesive Film Pressure Silicon Roller

11- Polyethylene Extruder and Side Wrapping Head12- Polyethylene Film Pressure Roller13- Water Cooling Circuit and Cooling Tunnel14- On-Line Holiday Detector15- Pipe Kick-Out Arms and Racks16- Pipe End Cleaning Machines17- Pipe Exit Racks

Optional Units1- Gas-Fired Flame Heating Furnace for pipe heating to the temperature of 220 degree C2- Chromate Application for surface treatment prior to coating process after blast cleaning3- Phosphate Treatment Unit4- Vacuum Cleaning and Magnetic Plate Unit5- Primary Inspection Station6- Solvent Cleaning Unit7- Inspection Station after blast cleaning process8- Final Inspection Station

3

TYPICALTYPICALTYPICALTYPICAL LAYOUT ANDLAYOUT ANDLAYOUT ANDLAYOUT AND

SYSTEM COMPONENTSSYSTEM COMPONENTSSYSTEM COMPONENTSSYSTEM COMPONENTS

PRD

Pipe ManufactSystems

8/8/2019 3-LAYER Coating of Pipes

5/13

VISUAL INSPECTION

PIPE ENDS PROTECTION

PREHEATING

ABRASIVE BLAST

VISUAL INPECTION

SURFACE TREATMENT

HEATING

PRIMER LAYER - FUSION BONDED EPOXY

ADHESIVE INTERMEDIATE LAYER EXTRUDED COPOLYMER FILM SIDE

TOP LAYER - EXTRUDED POLYETHYLENE FILM SIDE

COOLING

HOLIDAY DETECTION

PIPE END CLEANING

FINAL INSPECTION

STORAGE

REPAIR

E-COATING PROCESS

4

8/8/2019 3-LAYER Coating of Pipes

6/13

F-PROCESS PARAMETERS

1- Precleaning of the pipes prior to blast cleaning for :- removal of surface contaminations ( salts, soil, grease, oils, organic matter and contaminants )- loosening mill scale- removal of moistureMethods :- High Pressure Fresh Water for removal of salts and soil- Hydrocarbon solvent ( xylol or mineral spirits ) for removal of organic contaminations- Preheating of pipe surface by flame burners to 75 degree C for loosening mill scale, removing

moisture, burning of organic matter and conditioning pipe surface for blast cleaning.

4- Surface Treatment

Chromate pretreatment ( 1% - 5% of concentrated solution )

5- Coating Thickness :

- Epoxy powder 80 100 microns- Adhesive film 350 microns- PE film 1.5 3 mm

5

2- Shot/Grit Abrasive Blast Cleaning :

The purpose of cleaning is to obtainclean steel surface with the cleanlinessdegree of Sa 2 and an anchor patternwith the average profile depth of25 80 microns.

Blast cleaning may also removepipe defects ( slivers, burrs, laminations,

scabs, gouges ). If not, grinding can bealso used for removal of such defectson pipe surface.

3- Heating of the Pipes

The pipe surface shall reachthe temperature of 200 220degree C prior to powder epoxyapplication.

The pipe surface temperatureshall not exceed 270 degree C.Metallurgical or surface defectscan occur at over 270 degree C.Bluing or darkening of the pipesurface is an indication for overheating of pipes.

EXTERNAL SHOT BLAST MACHINEEXTERNAL SHOT BLAST MACHINEEXTERNAL SHOT BLAST MACHINEEXTERNAL SHOT BLAST MACHINE

INDUCTION HEATINGINDUCTION HEATINGINDUCTION HEATINGINDUCTION HEATING

PRD

Pipe ManufactSystems

8/8/2019 3-LAYER Coating of Pipes

7/13

6- Cleaning / Process Line Conveyors

The pipes move helically over the conveyors through :

- preheating unit- blast cleaning cabinet- chromate application- heating coil or flame heating furnace

- epoxy spray booth- water cooling tunnel

Adhesive and Polyethylene films are wrappedaround the pipe in a helical motionto form overlap.

7- Water Cooling

The pipes are cooled by water at least to70 degree C after extruded adhesiveand polyethylene film application.

8- Pipe End Preparation

All pipes are cleaned for field joint welding.The coatings at pipe ends are removedby rotary brushes for the length ( max. 150 mm )specified by related specification.

9- On-line Quality Control

- The pipes are tested on-line after cooling forholiday at 25 kV.

- Temperature check of pipe surface prior toepoxy powder spraying is done by infraredtemperature measurement device

0- On-line Spot Check

- Non destructive coating thickness measurement- Temperature check of the bare pipe surface after heating unit and coated pipe surface after

adhesive and polyethylene film application is done by manual roller type temperaturemeasurement device.

6

GENERAL VIEW FROM PE.GENERAL VIEW FROM PE.GENERAL VIEW FROM PE.GENERAL VIEW FROM PE. COATING PLANTCOATING PLANTCOATING PLANTCOATING PLANT

COOLING TUNNELCOOLING TUNNELCOOLING TUNNELCOOLING TUNNEL

HOLIDAY DETECTIONHOLIDAY DETECTIONHOLIDAY DETECTIONHOLIDAY DETECTION

8/8/2019 3-LAYER Coating of Pipes

8/13

G-PROCESS

Initially, pipe ends are covered by protectors to prevent the damage of pipe bevels from blasting and thenthe pipe is taken to cleaning line conveyors. The pipe is transferred to gas-heated burners in a spiralmovement on conveyors in order to remove the surface moisture. Then the pipe is fed to blasting unit. Steegrit and/or shot is used in blasting unit. The surface of pipe is cleaned. After blasting, the pipe surface isvisually inspected. The pipe having acceptable surface condition is transferred to process line conveyors brolling on pipe racks between cleaning line conveyors and process line conveyors.

The pipes are transferred end to end in

a spiral motion continuously on process conveyors.Initially the pipes are moved through inductionheating coils or gas-heated furnace. The pipesare heated to the temperature of 200 degree C.Then, epoxy powder ( primer ) is sprayed to pipesurface by electrostatic guns located inside the booth.The pipe surface temperature is monitored continuouslyby optical temperature measuring device.The adhesive film is applied by extruder on pipe in anoverlapping form. Just after adhesive film, polyethylenefilm is applied by other extruder to pipe surface inseveral overlapping forms.

The coated pipes are moved to pipe end cleaningmachine by rolling on the racks located at theend of process conveyor just after cooling sectionand holiday detector. The polyethylene coating on

the pipe ends are removed by rotating steel brush.

Polyethylene coated pipes are lifted with belts orrubber-coated forklift for moving to storage areaor loading to trucks.

7

Adhesive and polyethylene films are pressed bysilicon pressure rollers onto pipe surface to obtainuniform coating.

The pipe is transferred to water cooling sectionlocated just after extruders. The endless polyethylecoating is separated at the pipe ends to have singlpipe at the beginning of cooling section.Pipes are cooled to temperature below 70 degree C

The pipes are inspected by on-line holiday detectocontinuously at the end of cooling section. The pipemarked by spray gun if a pinhole is detected in thecoating.

PREHATING BEFORE SHOT BLAPREHATING BEFORE SHOT BLAPREHATING BEFORE SHOT BLAPREHATING BEFORE SHOT BLASTSTSTST

PIPE END CLEANING MACHINEPIPE END CLEANING MACHINEPIPE END CLEANING MACHINEPIPE END CLEANING MACHINE

PRD

Pipe ManufactSystems

EPOXY POWDEREPOXY POWDEREPOXY POWDEREPOXY POWDER

CABINETCABINETCABINETCABINET

AND EXTRUDERAND EXTRUDERAND EXTRUDERAND EXTRUDER

8/8/2019 3-LAYER Coating of Pipes

9/13

H-TYPES OF WRAPPING1- Adhesive and PE films to be applied on the bottom of the pipe.

Adhesive and PE extruders are located on floor and on the same side of the pipe.2- Adhesive and PE films to be applied on the top of the pipe

Adhesive and PE extruders are located on the same side of the pipe on a platform.The level of platform is adjustable according to the diameter of the pipe to be coated.

3- Adhesive film to be applied on the top of pipe and PE film to be applied on the bottom of the pipe.PE extruder is located on the floor and adhesive extruder is located at a lifting platformon the other side of the pipe.The level of lifting platform is adjustable according to the diameter of pipe to be coated

I-CAPACITIES OF THE MACHINES AND EQUIPMENTS*1- Blast cleaning machine ( roto jet double disc turbine type )

Grit / Shot rate ( toward the pipe surface ) : 200 -500 Kg / min at a velocity of 80 m / sec.Machine rate : 35 -75 kW / turbine

8

3- Induction Heating Unit

Power Supply : 500 kVA - 1800 kVAM.F. power rating : 400 kW - 1400 kWWorking frequency : 1000 Hz 4000 HzM.F. nominal rated voltage : 1000 V 1250 V INDUCTION HEATING COILINDUCTION HEATING COILINDUCTION HEATING COILINDUCTION HEATING COIL

SHOT BLAST MACHINESHOT BLAST MACHINESHOT BLAST MACHINESHOT BLAST MACHINE

AAAAND FLAME HEATINGND FLAME HEATINGND FLAME HEATINGND FLAME HEATING

2- Gas Fired Flame HeatingFurnace for process line

Heat Input : 6 million BTU / hour

FLAME HEATING FURNACEFLAME HEATING FURNACEFLAME HEATING FURNACEFLAME HEATING FURNACE

8/8/2019 3-LAYER Coating of Pipes

10/13

9

5- Electrostatic epoxy powder unit

Powder spray gun : 15 unitsElectrical field : 95 kV

* Above parameters are defined according to required coating capacity.

4- Extruders

Adhesive extruder output : 150 - 250 Kg / hPolyethylene extruder output : 1000 - 1500 Kg / h

PRD

Pipe ManufactSystems

ADHESIVE EXTRUDERADHESIVE EXTRUDERADHESIVE EXTRUDERADHESIVE EXTRUDER POLYETHYLENEPOLYETHYLENEPOLYETHYLENEPOLYETHYLENE EXTRUDEREXTRUDEREXTRUDEREXTRUDER

EPOXY POWDER ANDEPOXY POWDER ANDEPOXY POWDER ANDEPOXY POWDER AND

SYSTEM CONTROL PANELSYSTEM CONTROL PANELSYSTEM CONTROL PANELSYSTEM CONTROL PANELEPOXY POWDER CABINETEPOXY POWDER CABINETEPOXY POWDER CABINETEPOXY POWDER CABINET

8/8/2019 3-LAYER Coating of Pipes

11/13

K-REPAIR

There are two main repair methods in case the coating is damaged during the transportationand storage of the coated pipe and also during the pipe line construction.

1- Stick embedding method for small size repair2- Patch and tape method for large size repair

J-INSPECTIONS AND TESTS

The tests and inspections written below are carried out for assuring the quality of thecoating.

On-line continuous inspections and tests :

1- Surface Inspection2- Thickness Test

3- Temperature Check4- Holiday Inspection

Off-line periodical inspections and tests :

1- Impact Resistance Test2- Adhesion ( Peeling ) Resistance Test

3- Hardness ( Indentation ) Test4- Tensile ( Elongation ) Test5- Cathodic Disbonding Test6- Coating Resistivity Test

10

TENSILE TESTERTENSILE TESTERTENSILE TESTERTENSILE TESTER

8/8/2019 3-LAYER Coating of Pipes

12/13

11

PRD

Pipe ManufacSystem

SHOT BLAST LINESHOT BLAST LINESHOT BLAST LINESHOT BLAST LINE

COATING PLANTCOATING PLANTCOATING PLANTCOATING PLANT

GENERAL VIEWGENERAL VIEWGENERAL VIEWGENERAL VIEW

8/8/2019 3-LAYER Coating of Pipes

13/13

12

COATING LINECOATING LINECOATING LINECOATING LINE

COATING PLANTCOATING PLANTCOATING PLANTCOATING PLANT

GENERAL VIEWGENERAL VIEWGENERAL VIEWGENERAL VIEW