nace rp039402

StandardRecommended Practice

Application, Performance, and Quality Control ofPlant-Applied, Fusion-Bonded Epoxy External Pipe

Coating

This NACE International standard represents a consensus of those individual members who havereviewed this document, its scope, and provisions. Its acceptance does not in any respectpreclude anyone, whether he has adopted the standard or not, from manufacturing, marketing,purchasing, or using products, processes, or procedures not in conformance with this standard.Nothing contained in this NACE International standard is to be construed as granting any right, byimplication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, orproduct covered by Letters Patent, or as indemnifying or protecting anyone against liability forinfringement of Letters Patent. This standard represents minimum requirements and should in noway be interpreted as a restriction on the use of better procedures or materials. Neither is thisstandard intended to apply in all cases relating to the subject. Unpredictable circumstances maynegate the usefulness of this standard in specific instances. NACE International assumes noresponsibility for the interpretation or use of this standard by other parties and acceptsresponsibility for only those official NACE International interpretations issued by NACEInternational in accordance with its governing procedures and policies which preclude theissuance of interpretations by individual volunteers.

Users of this NACE International standard are responsible for reviewing appropriate health, safety,environmental, and regulatory documents and for determining their applicability in relation to thisstandard prior to its use. This NACE International standard may not necessarily address allpotential health and safety problems or environmental hazards associated with the use ofmaterials, equipment, and/or operations detailed or referred to within this standard. Users of thisNACE International standard are also responsible for establishing appropriate health, safety, andenvironmental protection practices, in consultation with appropriate regulatory authorities ifnecessary, to achieve compliance with any existing applicable regulatory requirements prior to theuse of this standard.

CAUTIONARY NOTICE: NACE International standards are subject to periodic review, and may berevised or withdrawn at any time without prior notice. NACE International requires that action betaken to reaffirm, revise, or withdraw this standard no later than five years from the date of initialpublication. The user is cautioned to obtain the latest edition. Purchasers of NACE Internationalstandards may receive current information on all standards and other NACE Internationalpublications by contacting the NACE International Membership Services Department, 1440 SouthCreek Drive, Houston, Texas 77084-4906 (telephone +1 [281] 228-6200).

Revised 2002-02-17Approved October 1994

NACE International1440 South Creek Dr.

Houston, Texas 77084-4906+1 (281)228-6200

ISBN 1-57590-147-1©2002, NACE International

NACE Standard RP0394-2002Item No. 21064

RP0394-2002

NACE International i

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Foreword

This standard recommended practice presents guidelines for establishing requirements to ensureproper application and performance of plant-applied, fusion-bonded epoxy (FBE) coatings to theexternal surfaces of pipe. It is intended for use by corrosion control personnel concerned withmitigation of corrosion on buried and submerged piping used for transportation and storage of oil,gas, water, and similar products.

This standard was originally prepared in 1994 by NACE Task Group T-10D-10, a component ofUnit Committee T-10D on Protective Coating Systems. It was revised in 2002 by NACE TaskGroup 031. This Task Group was administered by Specific Technology Group (STG) 03 onProtective Coatings and Linings—Immersion/Buried. Sponsoring STGs also included STG 05 onCathodic/Anodic Protection; and STG 35 on Pipelines, Tanks, and Well Casings. This standard isissued by NACE International under the auspices of STG 03.(1, 2)

In NACE standards, the terms shall, must, should, and may are used in accordance with thedefinitions of these terms in the NACE Publications Style Manual, 4th ed., Paragraph 7.4.1.9. Shalland must are used to state mandatory requirements. The term should is used to state somethingconsidered good and is recommended but is not mandatory. The term may is used to statesomething considered optional.

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___________________________(1) With permission of Canadian Standards Association (CSA), portions of this standard have been reproduced from CSA Standard Z245.20-M 98, “External Fusion Bonded Epoxy Coated Steel Pipe,” (Copyright CSA, 1986). Copies of Z245.20-M 98 may be purchased from CSA,178 Rexdale Boulevard, Toronto, Ontario, Canada, M9W 1R3.(2) With permission of the American Petroleum Institute, portions of this standard have been reproduced from API RP 5L7, “RecommendedPractices for Unprimed Internal Fusion Bonded Epoxy Coating of Line Pipe,” Second Edition, June 30, 1988, American Petroleum InstitutePublications and Distribution Section, 1220 L Street, NW, Washington, DC 20005.

RP0394-2002

ii NACE International

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NACE InternationalStandard

Recommended Practice

Application, Performance, and Quality Control of Plant-Applied, Fusion-Bonded Epoxy External Pipe Coating

Contents

1. General.......................................................................................................................... 12. Definitions...................................................................................................................... 13. Coating Material ............................................................................................................ 14. Coating Performance .................................................................................................... 35. Surface Preparation of Pipe .......................................................................................... 46. Coating Application ....................................................................................................... 57. Production Inspection and Testing................................................................................ 68. Repair............................................................................................................................ 89. Handling, Storage, and Shipping................................................................................... 910. Marking ......................................................................................................................... 9References.......................................................................................................................... 9Appendix A—Specific Gravity Determination.................................................................... 10Appendix B—Shelf Life Determination.............................................................................. 11Appendix C—Gel Time Determination.............................................................................. 11Appendix D—Glass Transition and Heat of Reaction Determination ............................... 12Appendix E—Moisture Analysis Determination ................................................................ 13Appendix F—Cathodic Disbondment Test........................................................................ 13Appendix G—Test for Porosity of the Coating .................................................................. 15Appendix H—Flexibility Test ............................................................................................. 16Appendix I—Impact Test .................................................................................................. 22Appendix J—Hot-Water Soak........................................................................................... 22Appendix K—Test for Interface Contamination of the Coating ......................................... 24FiguresFigure G1: Examples of Cross-Section Porosity ............................................................. 15Figure G2: Examples of Interface Porosity ...................................................................... 16Figure H1: Determination of Effective Strap Thickness................................................... 17Figure H2: Radii 3.18-mm (0.125-in.) Increments ........................................................... 18Figure H3: Radii 3.18-mm (0.125-in.) Increments ........................................................... 19Figure H4: Radii 3.18-mm (0.125-in.) Increments ........................................................... 20Figure H5: Radii 3.18-mm (0.125-in.) Increments ........................................................... 21TablesTable 1: Epoxy Powder Properties..................................................................................... 2Table 2: In-Plant Verification of Epoxy Powder Quality...................................................... 2Table 3: Qualification Requirements.................................................................................. 3Table 4: Production Test Ring Requirements.................................................................... 6

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RP0394-2002

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Section 1: General

1.1 This standard presents guidelines for establishingminimum requirements to ensure proper application andperformance of plant-applied, fusion-bonded epoxy (FBE)coatings to the external surfaces of pipe.

1.2 The function of such coatings is to prevent corrosionwhen used in conjunction with cathodic protection.

1.3 This standard suggests or describes methods forqualifying and controlling the quality of FBE pipe coatings,provides guidelines for their proper application, andidentifies inspection and repair techniques to obtain the bestapplied FBE coating system.

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Section 2: Definitions

Applicator: The organization responsible to the purchaserfor the coating application.

Batch: The quantity of coating material produced during acontinuous production run of not more than eight hours.

Coating: A liquid, liquefiable, or mastic composition that,after application to a surface, is converted into a solidprotective, decorative, or functional adherent film.

Coating material: Epoxy powder.

Cutback: The length of pipe left uncoated at each end forjoining purposes (e.g., welding).

Holiday: A discontinuity in a protective coating thatexposes unprotected surface to the environment.

Inspector: The authorized agent of the purchaser.

MSDS: Material safety data sheet.

PD: Pipe diameter.

Purchaser: The owner company or the authorized agencythat purchases the coated pipe.

Supplier: The manufacturer or distributor of the coatingmaterial and its authorized technician.

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Section 3: Coating Material

3.1 Coating Supplier Information

3.1.1 The coating material supplier shall furnish toboth the purchaser and the applicator the followinginformation in a written form upon request:

3.1.1.1 Directions for handling and storage of thecoating material,

3.1.1.2 Specification of the basic physical prop-erties and laboratory performance test results,

3.1.1.3 Certification of the determined physicalproperties of each batch of material, and

3.1.1.4 Material safety data sheets.

3.2 Handling of Coating Materials

3.2.1 Coating material batches shall be identified by abatch coding system devised by the supplier. Thebatch code shall include a reference to the date ofmanufacture. Coating materials shall be shipped andstored under cover according to the supplier’s recom-

mendations and in such a manner that contaminationor adverse effects on application are avoided.

3.2.2 Shelf Life

All batches on receipt and any batch of coatingmaterial that has exceeded the supplier’srecommended shelf life shall be subject to coatingmaterial verification tests by the manufacturer (seeParagraph 7.3.2) prior to use.

3.2.3 Copies of all records of testing by the applicatoror manufacturer shall be supplied to the purchaser orpurchaser’s representative within 24 hours of the testor as agreed to in the preproduction meeting(s).

3.3 Coating Material Properties

3.3.1 It is the supplier’s responsibility to perform thetests cited by reference in this section. The purchaseror applicator may also perform any or all of the citedtests as part of a quality assurance program.

3.3.2 The coating material shall meet the value limitsfor the properties listed in Table 1.

NACE International 1

RP0394-2002

TABLE 1: Epoxy Powder Properties

Property Value Limits Test MethodDensity

± 3.5%According to supplier’s specification See Appendix A

Particle Size 2% max. retained on 150 µm (100 mesh) sieve; 0.1% max.retained on 250 µm (60 mesh) sieve

Shelf Life According to supplier’s specification; according to supplier’srecommended storage conditions

See Appendix B

Gel Time According to supplier’s specification ± 20% See Appendix C(A)

Cure Cycle Capable of cure at temperatures below 275°C (527°F)(limitation imposed by regulations on heating of cold-expanded pipe); time: according to supplier’s specification

According tosupplier’sspecification

Glass Transition Temperatures According to supplier’s specification See Appendix D(A)

H (Heat of Reaction) According to supplier’s specification See Appendix D(A)

Moisture Content(B) 0.5% max. See Appendix E

___________________________(A) API RP 5L7(B) Either moisture or total volatile content may be determined at the supplier’s discretion.

3.3.3 All batches of FBE material shall be tested uponreceipt by the applicator, at its cost, according toParagraph 7.3.2 to verify that the FBE material meets

or exceeds the requirements of Table 2. This ensuresthe FBE material has been properly stored duringhandling and shipping.

TABLE 2: In-Plant Verification of Epoxy Powder Quality

Test Acceptance Criteria No. of TestSpecimens

Test Method

Cross-Section Porosity Rating of 1 to 3, inclusive 1 See Appendix G(A)

Interface Porosity Rating of 1 to 3, inclusive 1 See Appendix G(A)

Flexibility (2°/PD Permanent Strain) No cracks, tears, delamination, ordisbondment

3 See Appendix H

Gel Time According to supplier’s specification± 20%

1 See Appendix C(B)

Hot-Water Soak Rating of 1 to 3, inclusive 1 See Appendix J___________________________

(A) CAN/CSA Z245.20-M98(B) API RP 5L7

3.3.4 Any batch of FBE material that has exceededthe supplier’s recommended shelf life shall be testedaccording to Paragraph 7.3.2 to verify the FBE material

meets or exceeds the requirements of Table 2. Theserequalification tests shall be performed by the coatingmanufacturer, at its cost.

2 NACE International

RP0394-2002

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Section 4: Coating Performance

4.1 Typical desired characteristics of applied coatings areoutlined in NACE Standard RP0169.1

4.2 The coating shall not deteriorate (i.e., burn, blister, orchar) more than 50 mm (2 in.) from the extreme edge of aweld or cut area when pipe is welded or torch cut. Ifdeterioration of the coating occurs beyond 50 mm (2 in.)from the weld or cut area, the purchaser’s representativemust be notified to resolve the issue.

4.3 Performance Testing

4.3.1 Qualification

The coating system shall be qualified for production bytesting laboratory-coated test specimens for eachapplicable test and by meeting the acceptance criteria(see Table 3). It is the responsibility of the purchaseror coating applicator to qualify the coating material priorto coating application. Once qualification is establishedfurther qualification testing is not required unless thecoating material, formulation, or location of manu-facture changes.

TABLE 3: Qualification Requirements

Test Acceptance Criteria No. of TestSpecimens

Test Method

Cathodic Disbondment (24 h) Avg. radius: 6.0 mm (0.25 in.) 3 See Appendix F

Cathodic Disbondment (28 d) Avg. radius: 8 mm (0.3 in.) 3 See Appendix F

Cross-Section Porosity Rating of 1 to 4 3 See Appendix G(B)

Interface Porosity Rating of 1 to 4 3 See Appendix G(B)

Flexibility (3°/PD at 0°C [32°F] or -30°C [-22°F])(A) No cracks, tears, ordelamination

5 See Appendix H

Impact Resistance 1.5 J (13 in.-lb) min. 3 See Appendix I

Hot-Water Soak A rating of 1 to 3, inclusive 3 See Appendix J

___________________________(A) Use the 0°C (32°F) temperature test for situations in which the pipe will be field bent at or above these temperatures. Use the -30°C(-22°F) temperature test for situations in which the pipe will be field bent at or above these temperatures.(B) CAN/CSA Z245.20-M98

4.3.2 Performance Testing Steel Panels

Test panels shall be hot-rolled carbon steel (AISI(3)

1020 or approved equivalent) and have dimensions inaccordance with the cited test method. The surfaceshall be blast cleaned using steel grit that shall be usedduring production to provide a surface profile of 38 to100 µm (1.5 to 4.0 mils), measured from peak to valleyusing the following standards:

4.3.2.1 NACE No. 1/SSPC(4)-SP 5.2

4.3.2.2 NACE Standard RP0287.3

4.3.3 Coating of Test Panels

4.3.3.1 Coating application and curing shall be inaccordance with the supplier’s recommendations.Application and curing temperatures shall notexceed 275°C (527°F).

4.3.3.2 Coating thickness on the test panel shallbe 360 ±50 µm (14 ±2 mils). Magnetic pull-offcoating thickness gauges must be calibratedagainst a NIST(5) thickness standard (NIST-SRM13634) that is within 20% of the specified coatingthickness. Magnetic flux or fixed-probe gaugesmust be calibrated to SSPC-PA 2.5


___________________________(3) American Iron and Steel Institute (AISI), 1101 17th St. NW Suite 1300, Washington, DC 20036.(4) Society for Protective Coatings (SSPC), 40 24th St, 6th Floor, Pittsburgh, PA 15222-4656.(5) National Institute of Standards Technology (NIST), formerly the National Bureau of Standards, Gaithersburg, MD 20899.

RP0394-2002

4.3.4 Performance of Laboratory-Coated Steel Panels

4.3.4.1 Testing

A coating shall be considered qualified when theresults of a duplicate set of tests meet the accep-tance criterion for each test shown in Table 3.

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Section 5: Surface Preparation of Pipe

5.1 This section emphasizes the importance of propersurface preparation of the pipe because the condition of thisinterface directly affects the coating’s performance.

5.1.1 Bare pipe shall be supplied to the applicator freeof salts, mill lacquer, oil, grease, or other deleteriousdeposits. If any such deposits are present, the applic-ator shall attempt to remove any remaining deleteriousdeposits from the surface to be coated using theappropriate NACE/SSPC surface preparation standard.If the applicator cannot sufficiently remove thesedeposits these pipes may be rejected, or the applicatorand purchaser may agree on an appropriate solution.If a decision is made to reject the contaminated pipes,the rejection may be for individual pipes or lots of pipeaccording to the severity of the problem.

NOTE: Mill lacquer, other protective coatings, or solu-ble salt left on the pipe surface adversely affectscoating performance.

5.1.1.1 After blast cleaning, the pipe surface shallbe tested for the presence of soluble salts. If theconcentration is more than 2 µg/cm2 (0.0002gr/in.2), the pipe surface shall be cleaned in accor-dance with Paragraph 5.1.9 or another suitablemethod. The cleaned pipe shall be retested toconfirm the removal of soluble salts. The fre-quency and type of testing shall be determined bythe purchaser’s agent and applicator according tothe type and severity of the contamination.

5.1.2 All pipe shall be uniformly preheated prior toblast cleaning to remove moisture from the surface,assist in raising slivers, and provide the proper heatedsurface for the phosphoric acid wash. The preheatshall be sufficient to ensure that the pipe temperature isat least 3°C (5°F) above the dew point temperatureduring blast cleaning and inspection. The preheat tem-perature shall keep the pipe surface heated in theproper range (as recommended by the phosphoric acidmanufacturer) for phosphoric acid wash application, ifused.

5.1.3 The surface of the pipe shall be blast cleaned toNACE No. 2/SSPC-SP 106 or to ISO(6) 8501-1.7

5.1.4 Surface profile shall be at least 50 µm (2 mils)from peak to valley (see NACE Standard RP0287).Surface profile shall not exceed 100 µm (4 mils).

5.1.5 Bevels, lands, and internal coatings shall be pro-tected from shot/grit blasting and damage by impact orgouging.

5.1.6 Residual products from blasting shall be suitablyremoved from the interior and exterior surfaces of thepipe.

5.1.7 Prior to coating, the cleaned pipe shall be vis-ually inspected and imperfections that may cause holi-days in the coating shall be removed by grinding insuch a manner as to give a surface finish suitable forsubsequent application of coating, or by reblastingground areas. The maximum grinding area is 0.09 m2

(0.1 ft2) for each location, and the maximum total grindarea is the smaller of 0.2 m2 (2 ft2) for each joint or 2%of the total pipe surface. The disposition of any joint ofpipe that exceeds these limits shall be subject to agree-ment between the applicator and purchaser.

5.1.8 Disposition of pipe with imperfections that cannotbe removed without encroaching on minimum wallthickness or causing interference with the normal pro-duction cycle shall be subject to agreement betweenapplicator and purchaser.

5.1.9 Phosphoric acid wash and rinse may be used forfurther surface cleaning, etching, and removal of sol-uble salts. Phosphoric acid shall be mixed with deion-ized or reverse osmosis water according to the manu-facturer’s recommendations. Deionized or reverseosmosis water shall be used for the mixture and forrinsing the pipe after the wash. The deionized orreverse osmosis water shall have no more than 20ppm of total dissolved solids or 35 µS conductivity.8

The phosphoric acid wash shall be applied after theblast and before the heating process.

5.1.9.1 Application of the phosphoric acid mixtureshall be at the rate and percent recommended bythe phosphoric acid supplier, unless otherwiseapproved by the purchaser. The mixing container


___________________________(6) International Organization for Standardization (ISO), 1 rue de Varembe, Case Postale 56, CH-1121 Geneva 20, Switzerland.

RP0394-2002

shall be continually agitated during the applicationprocess. The concentration of the mixture shall bechecked by the applicator at least once every eighthours by sampling the mix at the spray head orapplication point.

5.1.9.2 The mixture shall stay on the pipe for atleast 20 seconds. The mixture shall have a pH ofone or less on the pipe surface 20 seconds afterthe mixture is applied. This pH shall be checkedby the applicator a minimum of every two hoursduring production.

5.1.9.3 The mixture shall be rinsed from the pipesurface with a high-pressure rinse system usingdeionized or reverse osmosis water meetingrequirements of Paragraph 5.1.9. The high-pres-sure rinse shall have a minimum tip pressure of220 kPa (1,500 psi).

5.1.9.4 The pH of the wet pipe surface after therinse shall be no less than 6 and no greater than7.5 and shall be checked by the applicator a mini-mum of every two hours during production.

5.1.10 Prior to heating the pipe, a chromate chemicaltreatment may be used to provide additional surfacepretreatment. This treatment is used to provide a con-version coating with the steel surface and create addi-tional surface energy to help attract and hold the FBE

powder. A chromate material specifically produced forthese types of applications shall be used. If a phos-phoric acid wash is used, the chromate solution shallbe applied after the phosphoric acid wash and rinse.

5.1.10.1 The chromate material shall be mixedwith deionized or reverse osmosis water (as inParagraph 5.1.9). The mix ratio shall be approvedby the chromate manufacturer.

5.1.10.2 The chromate should be applied by drip-ping or brushing on the pipe as it rotates down theconveyor. Brushes, noncontaminating wipes, orsqueegees shall be used to remove excesschromate mixture.

5.1.10.3 The mixture shall be thinly applied,leaving a light golden color on the pipe surface.

5.1.11 When approved or specified by the purchaser,additional surface treatments may be used prior toapplication of coating.

5.1.12 If used, these surface treatments can causethe pipe surface to discolor after heating to the propercoating application temperature and these surfaces willno longer meet the color requirements of Paragraph5.1.3. During preproduction, the applicator and pur-chaser’s representative shall agree to the acceptablecolor at this stage of production.

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Section 6: Coating Application

6.1 This section provides information on application tech-niques for obtaining optimum performance of FBE pipecoatings.

6.1.1 When changing from one coating manufactureror product to another, care should be taken to minimizecross-contamination of coating materials.

6.1.2 Application and curing temperatures of the exter-nal pipe surface shall be selected by the applicator,shall not exceed 275°C (527°F), and shall be in accord-ance with the coating supplier’s recommendations.

6.1.2.1 The use of recycled FBE powder shall bepermitted if the recycle system automatically andcontinuously blends recycled powder with a mini-mum of 80% virgin powder in the delivery system.

6.1.3 Cure schedule shall be selected by the appli-cator to ensure adequate cure of the coating, should bein accordance with the coating manufacturer’s recom-mendations, and shall be subject to approval by thepurchaser.

6.1.4 The minimum coating thickness shall be spec-ified by the purchaser. Maximum coating thickness may

also be specified by the purchaser, if there is concernabout field bending or application problems.

6.1.5 To meet the acceptance criteria in Table 4, thespecified minimum thickness should not be less than300 µm (12 mils) for any thickness reading.

6.1.5.1 When FBE coating is used in systems inwhich the service temperature of the coated surf-aces exceeds 65°C (150°F), thicker FBE mini-mums should be used. Suggested minimums are:

Service Temperature Minimum FBEThickness

65°C (150°F) to 82°C (180°F) 500 µm (20 mils)82°C (180°F) to 95°C (203°F) 760 µm (30 mils)Above 95°C (203°F) Consult FBE

supplier/applicator.

CAUTION: If the pipe bends are to be made in temp-eratures below -10°C (14°F), greater thicknesses maycause the coating to crack or stretch, causing repairproblems during construction.

6.1.5.2 Other situations that may require a higherFBE minimum thickness are:


RP0394-2002

• When the pipe is to be concrete coated;• Placed through a drilled crossing;• Rocky or high-impact backfill; and• Mechanical damage during construction.

6.1.6 The cutback limits shall be specified by thepurchaser.

TABLE 4: Production Test Ring Requirements

Test TestType(A)

Acceptance Criteria No. of TestSpecimens

Test Method(B)

Cathodic Disbondment (24 h) A Max. radius: 8 mm (0.3 in.) 1 See Appendix F

Flexibility (1.5°/PD Permanent Strain) A No cracks, tears, or delamination(unaided visual)

3 See Appendix H

Hot-Water Soak A Rating of 1 to 3, inclusive 1 See Appendix J

Interface Contamination B Max.: 30% 1 See Appendix K(C)

Cross-Section Porosity B Rating of 1 to 3, inclusive 1 See Appendix G(C)

Thermal Characteristics C ∆Tg of 5°C (9°F), max. or 95%conversion H minimum

1 See Appendix D

Impact Resistance C 1.5 J (13 in.-lb) minimum 1 See Appendix I___________________________

(A) Failure to meet the acceptance criteria for Type A tests shall be grounds for rejection of all pipe coated after the previous acceptable testresult and prior to the next acceptable test result. Additional Type A testing of the affected day’s production may be conducted in an attemptto reduce the amount of rejected pipe. Failure to meet the acceptance criteria for Type B or C tests shall be grounds for requiring changes tothe application process parameters. Type C tests are required only when specified by purchaser. NOTE: The purchaser may require thatthe applicator limit the application process until the cause of the failure has been remedied.(B) Purchaser may specify more stringent requirements for specific applications. These requirements must be clearly documented and agreedto by purchaser and applicator before preproduction.(C) CAN/CSA Z245.20-M98

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Section 7: Production Inspection and Testing

7.1 Plant Access

The inspector representing the purchaser shall have freeaccess to all parts of the applicator’s plant concerned withthe storage, application, testing, and handling of the FBEpowder and coating of the purchaser’s pipe, while work onthe contract of the purchaser is being performed. Theinspection should be performed by a person qualified byexperience and training in coating inspection methods. Theapplicator shall afford the inspector, without charge, inspec-tion facilities to satisfy the inspector that the coating is beingapplied in accordance with the requirements of this stand-ard. All inspections shall be made at the place of appli-cation prior to shipment of the coated pipe, unless other-wise specified by the purchaser, and shall be conducted soas not to interfere unnecessarily with the operation of theplant.

7.1.1 Inspection Records

Copies of all records from quality control, inspection,and testing by the applicator shall be supplied to the

purchaser or purchaser’s representative within 24hours of the inspection or test.

7.2 Inspection Notice

If the inspector representing the purchaser desires toinspect the coated pipe or witness the tests, the applicatorshall give reasonable notice of the time at which the appli-cation or tests are to be made.

7.3 Production Tests

7.3.1 The applicator is responsible for and shall havesuitable equipment and trained personnel at the plantto perform Type A and B tests as required by Table 4.

7.3.2 Verification of FBE Powder Quality

7.3.2.1 The minimum testing frequency shall beone sample from each batch of FBE powderreceived. Tests conducted and the acceptancerequirements shall be in accordance with Para-graphs 7.3.2.2 and 7.3.2.3. For stock-stored FBE


RP0394-2002

powder, gel time shall be retested prior to eachuse, in accordance with Appendix C.

7.3.2.2 Laboratory-coated test specimens shall beprepared at the proposed plant application temper-ature in accordance with the requirements of Para-graphs 4.3.2 and 4.3.3.

7.3.2.3 The tests to be conducted and the accept-ance criteria are shown in Table 2.

7.3.3 In-Line Inspection and Measurement

7.3.3.1 General

The inspection and measurements required byParagraphs 7.3.3.1 through 7.3.3.8 shall be madeand recorded by the applicator under the super-vision of a person qualified by experience andtraining in coating inspection methods.

(7)

7.3.3.1.1 Air for blasting, cleaning, drying, orpowder application shall be checked andinformation recorded at least every four hoursto ensure no water, oil, or other contaminantsare present.

7.3.3.1.2 All temperature, dew point, humid-ity, and other such measurements as requiredby the coating manufacturer or applicatorshall be taken and recorded at the start ofeach shift and at least once every two hours.

7.3.3.2 Surface Finish

Surface finish shall be monitored hourly to deter-mine compliance with Paragraph 5.1.3.

7.3.3.3 Surface Profile

At least once every four hours of production thesurface profile shall be measured using a repli-cating film or approved equivalent. The profileshall be within the limits specified in Paragraph5.1.4.

7.3.3.4 Surface Inspection

Each cleaned pipe shall be visually inspected forsurface defects and surface imperfections thatmay cause holidays in the coating. Surface imper-fections shall be removed by grinding or other suit-able means in accordance with Paragraphs 5.1.7and 5.1.8. Pipe containing surface defects shallbe rejected or repaired at the purchaser’s option.

7.3.3.5 Application Temperature

The surface temperature of the pipe immediatelyprior to FBE powder application shall be monitoredand controlled within the limits agreed on by theapplicator, the purchaser, and the coating supplier.

7.3.3.5.1 Optical pyrometers, graduatedheat-indicating sticks, or other purchaser-approved methods shall be used to monitorand control the temperature.

7.3.3.5.2 Pyrometers and other such temper-ature-monitoring devices shall be calibratedand information recorded daily.

7.3.3.5.3 Once the coating temperature isestablished, the temperature of every fifthpipe shall be taken and recorded.

7.3.3.6 Curing

The curing temperature and the time intervalbetween application and quenching shall be con-trolled and monitored in accordance withParagraphs 6.1.2 and 6.1.3.

7.3.3.7 Coating Thickness

7.3.3.7.1 The coating thickness shall bemeasured at five locations along the length ofeach coated pipe using a coating thicknessgauge calibrated at least once every fourhours during production, in accordance withthe requirements of Paragraph 4.3.3.2. Eachreading shall be at least 2 m (6 ft) from anyother reading. All five of these thicknessmeasurements shall be recorded.

7.3.3.7.2 If any individual measured thick-ness value is less than the specified minimumvalue of Paragraph 6.1.4, two coating thick-ness measurements shall be measured within150 mm (6.0 in.) of the original measurement.The average of these measurements shallexceed the specified minimum value, and noindividual value shall be more than 50 µm (2.0mils) below the specified minimum value. Allthese thickness measurements shall berecorded.

7.3.3.7.3 Pipe failing to meet the require-ments of Paragraph 7.3.3.7.2 shall, at thepurchaser’s option, be accepted, repaired, orstripped and recoated.


___________________________(7) NACE International offers coating inspection certification and training programs. Contact the NACE International Membership ServicesDepartment for information.

RP0394-2002

7.3.3.7.4 If the purchaser’s maximum thick-ness is exceeded, the pipe shall be placed onhold for further inspection, special marking, orstripping and recoating, as agreed on by thepurchaser’s representative and the applicator.

7.3.3.8 Further Inspection

7.3.3.8.1 General

7.3.3.8.1.1 The entire coated surface ofeach length of pipe shall be inspectedwith a holiday detector in accordancewith NACE Standard RP0490.9

7.3.3.8.1.2 Inspection is best performedwhen the temperature of the coating islower than 90°C (194°F).

7.3.3.8.1.3 The coated surface shall be100% visually inspected to ensure it isfree of blisters, bubbles, sags, voids, andother irregularities.

7.3.3.8.2 Acceptance Criteria

7.3.3.8.2.1 Pipe containing holidaysshall be repaired or recoated in accord-ance with the requirements of Section 8.

7.3.3.8.2.2 The maximum number ofrepairs is on average one for each 2 m2

(22 ft2) of coated pipe surface, for pipesof all diameters.

7.3.3.8.2.3 The allowable number andtype of coating surface defects shall bespecified by the purchaser.

7.3.4 Production Test Rings

7.3.4.1 Test rings shall be a minimum of 460 mm(18 in.) long.

7.3.4.2 For each pipe size (distinct combination ofdiameter and wall thickness), the minimum fre-quency of obtaining test rings should be onesample for each of the following lots or fractionthereof:

7.3.4.2.1 One during each shift (maximumshift—12 hours), unless the pipe size ischanged. At least one test should be madeon each pipe size or wall thickness.

7.3.4.3 The tests to be conducted by the appli-cator and the acceptance criteria for test rings areshown in Table 4.

7.3.4.4 If the test results do not meet the criteriaof Table 4, additional test rings can be taken andretested. If these tests pass, all pipes betweenthis test and the last successful test can be accep-ted. If the second set of tests fail, additional brac-ket tests can be performed to isolate problempipes.

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Section 8: Repair

8.1 All coating defects should be repaired using materialsthat are compatible with, have the same or better perfor-mance at the expected service temperature, adhere well tothe FBE coating, and are approved by the purchaser.

8.2 Repair materials normally consist of:

8.2.1 Heat melting sticks, and

8.2.2 Two-part epoxy or equivalent.

8.3 Repaired areas should overlap the parent coating aminimum of 13 mm (0.50 in.). The surface to be repairedshould be suitably prepared to ensure adhesion of therepair material. Minimum thickness of the repaired coatingshall be in accordance with the repair coating manu-facturer’s recommendations.

8.3.1 Areas 6.4 mm (0.25 in.) in diameter and smallermay be repaired with the supplier’s recommended hot-melt stick, two-part epoxy, or equivalent.

8.3.2 Areas greater than 6.4 mm (0.25 in.) in diameterand less than 130 cm2 (20 in.2) shall be repaired withthe purchaser’s or powder supplier’s recommendedtwo-part epoxy or equivalent.

8.3.3 The total maximum repaired areas for each pipeshall not exceed 520 cm2 (80 in.2).

8.4 For stripping, pipe shall be heated to a temperature notexceeding 275°C (527°F) in order to soften the coating topermit removal by scraping, followed by abrasive blasting.All coating shall be removed prior to recoating. The identityof each stripped and recoated pipe shall be recorded.


RP0394-2002

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Section 9: Handling, Storage, and Shipping

9.1 After being externally coated and cured, the pipeshould be sufficiently cooled to permit handling.

9.2 Coated pipe shall be handled in such a way that dam-age to the pipe and coating is avoided. Equipment used inthe handling and storage of coated pipe shall be approp-riately padded.

9.3 Coating that is damaged during handling, storage, orshipping shall be repaired in accordance with the require-ments of Section 8 of this standard. The applicator isresponsible for repairing damage that occurs during thehandling, storage, and shipping activities under its control.Repair to damage that occurs after the applicator no longercontrols the pipe activity is the responsibility of the pur-

chaser. While under the control of the applicator, coatingdamage that exceeds the limits of Paragraph 7.3.3.8 shallbe stripped and recoated, unless accepted by the pur-chaser. Coating damage that occurs after the pipe leavescontrol of the applicator and exceeds the limits of Paragraph7.3.3.8 shall be the responsibility of the purchaser.

9.4 When loading or storing pipe, each pipe should beprotected using full-encirclement separators. The separ-ators shall be located within 0.9 m (3 ft) of the pipe endsand at one or more approximately equidistant intermediatelocation(s) less than 5.5 m (18 ft) apart. Separators nearthe pipe ends shall not interfere with the readability ofidentification markings.

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Section 10: Marking

10.1 As specified, the following identification markings shallbe placed on the coating:

10.1.1 Applicator’s name or mark (work ordernumber),

10.1.2 Markings required by the applicable pipe spec-ification or standard (grade, weight, manufacturer, etc.),

10.1.3 Date of coating application,

10.1.4 Coating material identification, and

10.1.5 Additional markings as desired by the appli-cator or requested by the purchaser (e.g., purchaseorder number).

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References

1. NACE Standard RP0169 (latest revision), “Control ofExternal Corrosion on Underground or Submerged MetallicPiping Systems” (Houston, TX: NACE International).

2. NACE No. 1/SSPC-SP 5 (latest revision), “White MetalBlast Cleaning” (Houston, TX: NACE International, andPittsburgh, PA: SSPC).

3. NACE RP0287 (latest revision), “Field Measurement ofSurface Profile of Abrasive Blast Cleaned Steel SurfacesUsing a Replica Tape” (Houston, TX: NACE).

4. NIST SRM 1363, “Non-Magnetic Coating on Steel,”Certified Coating Thickness Calibration Standards(Gaithersburg, MD: NIST).

5. SSPC-PA 2, “Measurement of Dry Coating Thicknesswith Magnetic Gages” (Pittsburgh, PA: SSPC).

6. NACE No. 2/SSPC-SP 10 (latest revision), “Near-WhiteMetal Blast Cleaning” (Houston, TX: NACE International,and Pittsburgh, PA: SSPC).

7. ISO 8501-1 (latest revision), “Preparation of SteelSubstrates Before Application of Paints and RelatedProducts—Visual Assessment of Surface Cleanliness”(Geneva, Switzerland: ISO).

8. ASTM(8) D 1125 (latest revision), “Standard TestMethod for Electrical Conductivity and Resistivity of Water”(West Conshohocken, PA: ASTM).

9. NACE Standard RP0490 (latest revision), “HolidayDetection of Fusion-Bonded Epoxy External PipelineCoatings of 10 to 30 mils (0.25 to 0.76 mm)” (Houston, TX:NACE International).


___________________________(8) ASTM International (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428.

RP0394-2002

10. ASTM G 95 (latest revision), “Standard Test Method forCathodic Disbondment Test of Pipeline Coatings (AttachedCell Method)” (West Conshohocken, PA: ASTM).

11. ASTM G 14 (latest revision), “Standard Test Method forImpact Resistance of Pipeline Coatings (Falling WeightTest)” (West Conshohocken, PA: ASTM).

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Appendix A—Specific Gravity Determination

Section A1: Scope

A1.1 To determine the specific gravity of a coatingmaterial.

A1.2 Two procedures are specified: the liquid displace-ment method and the pycnometer method. The procedureused must be designated on the supplier’s data sheet.Whether the test is run on powder or cured coating mustalso be specified.

Section A2: Equipment

A2.1 Volumetric flask, 100 mL

A2.2 Balance accurate to 0.1 g

A2.3 Mineral spirits (aliphatic Hydrocarbon BP) havingdensity of DL

Section A3: Procedure

A3.1 Procedure A—Liquid Displacement Method

A3.1.1 This method is used to determine the densityof coating material by the liquid displacement method.

A3.1.2 All apparatus, samples, water, and mineralspirits must be conditioned to room temperature for aminimum of two hours prior to testing.

A3.1.3 Accurately weigh the flask and record theweight, which is designated WF.

A3.1.4 Add approximately 20 g of coating material tothe flask and weigh the flask with coating material.This weight is designated WFP.

A3.1.5 Add sufficient mineral spirits to cover and wetthe coating material. Place the stopper on the flaskand agitate it for several minutes in order to ensure thatthere are no air pockets or lumps of dry coating mat-erial. Wash the stopper and walls of the flask with min-eral spirits until they are free of any coating materialsand fill the flask to the 100-mL level. Weigh the flask,coating material, and liquid together to obtain WFPL.

A3.1.6 Calculate the density of the coating accordingto Equation (A1):

L

FPFPL

FFP

D

)W(W100

WWdensity

−−

−= (A1)

A3.1.7 Clean and dry the flask, fill the flask withdistilled water to the 100-mL level, and weigh. Thisweight is designated W

FW.

A3.1.8 Clean and dry the flask, fill with mineral spiritsto the 100-mL level, and weigh it to determine theweight (W

FL) of the mineral spirits used.

A3.1.9 Calculate the specific gravity of the coatingmaterial according to Equation (A2):

)W)](WW(W)W[(W

)W)(WW(gravitySpecific

FFWFPFPLFFL

FFLFFPW

−−−−−−

= (A2)

A3.2 Procedure B—Pycnometer Method

A3.2.1 This procedure determines the density ofthe powder that can be expressed in units ofg/cm3. Specific gravity is dimensionless; however,the numbers are the same.

A3.2.2 Determine the density of the coatingmaterial using an air-comparison pycnometer orequivalent, in accordance with the instrumentmanufacturer’s instructions.


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NOTE: Both specific gravity and density vary withtemperature. The differences that may be ob-served within normal room temperature ranges arewithin the accuracy of the method.

Section A4: Report

A4.1 The following information shall be reported:

A4.1.1 Manufacturer, product code, batch number,and date tested; and

A4.1.2 Specific gravity or density.

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Appendix B—Shelf Life Determination

Section B1: Scope

B1.1 To estimate the shelf life of coating materials

Section B2: Equipment

B2.1 0.5-L (pint) glass jars and lids

B2.2 Oven

B2.3 Gel time apparatus

Section B3: Procedure

B3.1 Record the initial gel time (see Appendix C) of thecoating material. Place a sample of the coating materialinto each of two jars and screw on the lids. Store one sam-ple at 24°C (75°F) and the other sample in an oven at 43°C

(109°F). Evaluate the 24°C (75°F) sample monthly and the43°C (109°F) sample weekly. To evaluate the samples, lookfor evidence of hard caking of the coating material in the jar.Remove a portion of sample and measure the gel time (seeAppendix C).

B3.2 A 30% reduction in gel time indicates the shelf lifehas been exceeded.

Section B4: Report

B4.1 The following information shall be reported:

B4.1.1 Manufacturer, product code, batch number,and date tested; and

B4.1.2 Shelf life in days for each test temperature.

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Appendix C—Gel Time Determination

Section C1: Scope

C1.1 To determine the gel time of a coating material.

C1.2 Two procedures are allowed for gel time determin-ation; the procedure used must be reported on the sup-plier’s data sheet. Tests shall be made in triplicate andaveraged.

Section C2: Equipment

C2.1 Hot plate

C2.2 Stop watch or electric timer (0.1-second interval)

C2.3 Spatula

C2.4 Draw-down bar with gap depth of approximately 600µm (0.024 in.)

C2.5 Stiff wire

C2.6 Calibrated thermometer or contact pyrometer (cap-able of measuring temperature of hot plate surface)

Section C3: Procedure

C3.1 Procedure A

C3.1.1 Determine gel time by placing approximately1 g of coating material on a hot plate stabilized at 204±3°C (400 ±5°F). Take the temperature by placing thethermometer or contact pyrometer on the top center ofthe heated surface. Use a spatula to coat out at least650 mm2 (1.0 in.2) to a uniform thickness of 300 to 350µm (0.012 to 0.014 in.). Start the timer as soon as thecoating material is applied to the hot plate surface. Stirthe coating with a stiff wire or spatula, and stop thewatch when the coating becomes an unstirrable gel-atinous product. The elapsed time is the gel time.

C3.2 Procedure B

C3.2.1 Adjust and stabilize the hot plate to 204 ±3°C(400 ±5°F). Take the temperature by placing the ther-mometer or contact pyrometer on the top center of theheated surface. Place enough powder on the draw-down tool to create a tongue of epoxy powder approx-imately 25 mm (1.0 in.) wide and 50 mm (2.0 in.) long.In a smooth motion, deposit and draw the epoxy pow-


RP0394-2002

der across the metal plate while holding the tool at anangle of approximately 45° to the hot plate surface.Start the timing device and deposition of the powder onthe hot plate surface simultaneously. Applying onlylight pressure on the spatula, draw it through themelted powder at short intervals.

C3.2.2 The gel time is the length of time from whenthe film is applied until the spatula rides up on thegelled surface.

Section C4: Report

C4.1 The following information shall be reported:

C4.1.1 Manufacturer, product code, batch number,and date tested; and

C4.1.2 Gel time in seconds and procedure used.

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Appendix D—Glass Transition and Heat of Reaction Determination

Section D1: Scope

D1.1 To determine the glass transition temperature (Tg)and the amount of exothermic heat of reaction (∆H) ofepoxy powder or FBE pipe coating.

D1.2 Round-robin comparisons between laboratories haveresulted in significant variation in all parameters measured.Achieving comparable results between laboratories requiresstrict compliance with this test procedure followed by labor-atory comparison testing.

Section D2: Equipment

D2.1 Differential scanning calorimeter (DSC) and acces-sories

D2.2 Analytical balance accurate to 0.1 mg

D2.3 Knife or file

D2.4 Aluminum pan with cover

D2.5 An inert gas, such as nitrogen

Section D3: Procedure

D3.1 Obtain a 10 ±1-mg sample of FBE powder or coatingas applicable.

D3.2 Place the sample in a preweighed aluminum panand put cover in place. Crimp the cover into place with theencapsulating press and obtain the sample weight by sub-tracting pan and cover weight from the total weight. Place asmall vent hole in the lid without damaging the pan.

D3.3 Place sample and reference (as suggested by theinstrument supplier) in the DSC cell.

D3.4 Use an inert gas, such as dry nitrogen, to purge thecell.

D3.5 Heat the sample to just beyond the glass transitiontemperature (Tg0 for coating powder; Tg1 for coating chip)using a heating rate of 20°C (36°F)/min. Do not record thisscan.

D3.6 Immediately after heating, cool the DSC to 20°C(68°F) or below.

D3.7 Using a programmed rate of 20°C (36°F)/min, heatthe sample from 25°C (77°F) to a point about 25°C (45°F)beyond the end of the expected exothermic reaction regionas determined from a coating material (powder) scan.Record this scan. Name the glass transition measured inthis scan Tg1 if the sample is a coating chip, or Tg0 if thesample is coating material (powder).

D3.8 As in Paragraph D3.6, cool the DSC cell to 20°C(68°F) or below and proceed to the next run immediately.

D3.9 Heat the sample at 20°C (36°F)/min, recording thesecond scan from 25°C (77°F) to a point about 25°C (45°F)past the glass transition. Name the glass transition meas-ured in this scan Tg2 if the sample is a coating chip or TgF ifthe sample is the coating material (powder).

Section D4: Calculations

D4.1 The Tg is taken as the point of intersection of theextrapolated baseline at the low-temperature end and thetangent to the curve at the inflection point.

D4.2 Calculate the residual exothermic heat of reaction(∆H1) following the instructions provided by the manu-facturer of the DSC equipment.

D4.3 For coating chips, determine the change in the Tg

value (∆Tg) by using Equation (D1).

∆Tg

= Tg2

- Tg1 (D1)

D4.4 Calculate the percent conversion using Equation(D2).

100x∆H

)∆HH(1

−∆(D2)

Where∆H = amount of exothermic heat of reaction∆H1 = residual exothermic heat of reaction


RP0394-2002

Section D5: Report

D5.1 The following information shall be reported:

D5.1.1 Manufacturer, product code, batch number,and date tested;

D5.1.2 Pipe sample identification, if applicable;

D5.1.3 Tg0, TgF, and ∆H for coating material (powder),and Tg1, Tg2, ∆Tg, and ∆H1 for coating, including units;

D5.1.4 Type of apparatus used; and

D5.1.5 Percent conversion.

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Appendix E—Moisture Analysis Determination

Section E1: Scope

E1.1 To determine moisture content of FBE powder bydirect titration with Karl Fischer reagent to an electrometricendpoint.

Section E2: Equipment and Reagents

E2.1 Equipment

E2.1.1 Aquameter apparatus

E2.1.2 Lab mill

E2.1.3 Analytical balance

E2.1.4 15-mL serum bottle and cap

E2.1.5 Spatula

E2.1.6 Metal pipette holder—1 mL

E2.1.7 1-mL syringe

E2.1.8 100-mm (4-in.) hypodermic needle

E2.1.9 Plastic syringe (10 mL)

E2.1.10 Automatic buret (50 mL)

E2.2 Reagents

E2.2.1 Chloroform (trichloromethane)

E2.2.2 Generator solution

E2.2.3 Vessel solution (Parts A and B)

E2.2.4 Neutralizing solution

E2.3 Safety Precautions

E2.3.1 Karl Fischer reagent is toxic. During handlingof the solutions, avoid breathing of the vapors, andperform all operations in a well-ventilated area.

E2.3.2 Follow the MSDS instructions for personalprotection requirements.

Section E3: Procedure

E3.1 Run duplicate samples following the instrumentmanufacturer’s instructions.

Section E4: Report

E4.1 The following information shall be reported:

E4.1.1 Manufacturer, product code, batch number,and date tested; and

E4.1.2 Percent moisture content for each sampleand the average moisture content.

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Appendix F—Cathodic Disbondment Test

Section F1: Scope

F1.1 This test provides an assessment of the resistanceof the coating to disbondment when subjected to cathodicprotection. This test is similar to ASTM G 95.10 This pro-cedure covers both the 28-day qualification test and the 24-hour qualification and production test.

Section F2: Equipment

F2.1 DC power supply unit

F2.2 Platinum or platinum-coated anode wire

F2.3 Electrolyte solution consisting of 3 wt% sodiumchloride (NaCl) in distilled water


RP0394-2002

F2.4 Plastic cylinder 89 mm (3.5 in.) diameter, 100 mm (4in.) long

F2.5 High-impedance voltmeter

F2.6 Hot plate or oven capable of maintaining 66 ±3°C(150 ±5°F)

F2.7 Calomel reference electrode

F2.8 Utility knife

Section F3: Test Specimen

F3.1 Laboratory-Coated Specimen

F3.1.1 The minimum dimensions of the specimenshall be 100 mm (4 in.) square x 6 mm (0.25 in.) thick.The specimen shall be prepared and coated in accord-ance with Paragraphs 4.3.2 and 4.3.3.

F3.2 Test-Ring Specimen

F3.2.1 The test specimen shall be a 100-mm (4-in.)square segment cut from the test ring.

F3.3 A 3.3-mm (0.13-in.)-diameter holiday shall be drilledin the coating at the center of the specimen.

F3.4 A plastic cylinder shall be attached to the test spec-imen with the holiday at the center of the cylinder. This cyl-inder shall have an inside diameter not to exceed 100 mm(4 in.), but not less than 75 mm (3.0 in.).

Section F4: Procedure

F4.1 Pour approximately 350 mL of electrolyte, heated tothe proper test temperature, into the plastic cylinder.

F4.2 When testing specimens cut from pipe, use a heat-transfer medium (e.g., steel shot or grit) to provide uniformheating of the test specimen. Use of a metal pan partiallyfilled with the heat-transfer medium into which the specimenis implanted is preferred. Place on a hot plate or in an ovento maintain the electrolyte temperature at 66 ±3°C (150±5°F) for the 24-hour test. Immerse the thermometer andrest it on the test specimen. Run the 28-day test at 20 ±3°C(68 ±5°F).

F4.3 Connect the negative lead from the power supply tothe test specimen and the positive lead to the anode afterthe test temperature is reached.

F4.4 Turn on the power supply and apply voltage to thetest specimen: negative 3.5 V with respect to the calomel

reference electrode for the 24-hour test and negative 1.5 Vfor the 28-day test.

F4.5 Monitor the voltage, temperature, and electrolytelevel at the start, and at every 24-hour interval thereafter.For the 28-day test, the electrolyte level need not be moni-tored on weekends or other non-working days if a coverplate is loosely fitted over the test cell. Add distilled wateras required to maintain the electrolyte level. The electrolytelevel shall be maintained at ±25% of the original level andcylinders shall be marked to indicate such.

F4.6 Evaluation Procedure

F4.6.1 After 24 hours, remove the 24-hour test cellfrom the hot plate or oven, immediately drain the elec-trolyte from the cell, rinse with tap water, dismantle thetest cell, and air cool the sample to room temperature.The evaluation shall be performed within one hour ofremoval from the hot plate. After 28 days, remove the28-day test cell using the same procedure.

F4.6.2 Using a utility knife, make 8 radial cuts fromthe edge of the holiday outward through the coating tothe substrate. The radial cuts shall be at least 20 mm(0.8 in.) in length.

F4.6.3 If possible insert the blade of a utility knifeunder the coating at the holiday edge. Using a leveringaction, chip off the coating. Continue until the coatingdemonstrates a definite resistance to the leveringaction.

F4.6.4 Measure the radius of the disbonded areafrom the holiday edge along each radial cut and aver-age the measured results.

Note: The cathodic disbondment is relatively equal radiusfrom the holiday edge and does not extend down the radialcut. The coating should not be removed by “forcing” thecoating off at the radial cuts. The coating disbondment areais normally easily removed.

Section F5: Report

F5.1 The following information shall be reported:

F5.1.1 Manufacturer, product code, batch number,and date tested;

F5.1.2 Pipe identification, if applicable; and

F5.1.3 Average disbonded radius and length oflongest disbonded area.


RP0394-2002

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Appendix G—Test for Porosity of the Coating

Section G1: Scope

G1.1 To determine the degree of porosity or voids in theapplied coating

Section G2: Equipment

G2.1 Microscope

G2.2 Bench vise or guided-bend jig

G2.3 Dry ice or freezer

G2.4 Utility knife

Section G3: Test Specimen

G3.1 Laboratory-coated test specimens shall be approx-imately 200 mm (8 in.) long x 25 mm (1.0 in.) wide x 6 mm(0.25 in.) thick. Specimens shall be prepared and coated in

accordance with Paragraphs 4.3.2 and 4.3.3. Specimensfrom test rings shall be approximately 200 mm (8 in.) long x25 mm (1.0 in.) wide x pipe wall thickness, with the 200-mm(8-in.) dimension parallel to the axis of the pipe.

Section G4: Procedure

G4.1 Cool the test specimen to a temperature low enoughto allow removal of the coating when bent over a sharpradius.

G4.2 Pry off a piece of coating from the bent test spec-imen and examine the coating for porosity at 30X to 40Xmagnification.

G4.3 Rate the cross-section porosity in the coating bycomparing it to the photographs shown in Figure G1.

G4.4 Rate the interface porosity by comparison withFigure G2.

Figure G1:Examples of Cross-Section Porosity

Rating 1

Rating 2

Rating 3

Rating 4

Rating 5


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Figure G2:Examples of Interface Porosity

Rating 1

Rating 2

Rating 3

Rating 4

Rating 5

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Appendix H—Flexibility Test

Section H1: Scope

H1.1 To evaluate flexibility of the coating for field bending

Section H2: Equipment

H2.1 Press

H2.2 Bending mandrels of fixed radii (Procedure A) orfour-point bending apparatus (Procedure B)

H2.3 Freezer

H2.4 Microscope

Section H3: Test Specimen

H3.1 Laboratory-Coated Specimen

Each specimen shall be approximately 200 mm (8 in.) longx 25 mm (1.0 in.) wide x 6 mm (0.25 in.) thick. The testspecimen shall be prepared and coated in accordance withParagraphs 4.3.2 and 4.3.3.

H3.2 Test-Ring Specimen

Each specimen shall be approximately 200 mm (8 in.) longx 25 mm (1.0 in.) wide x pipe wall thickness, with the 200-mm (8-in.) dimension parallel to the axis of the pipe.

Section H4: Procedure

H4.1 Ensure the test specimen edges have all stressraisers removed and that substrate is exposed along theedges. Place the test specimens in the freezer, cool themto -18°C (0°F) if the bend is to be performed at 0°C (32°F),and hold for at least one hour. If the bend is to be per-formed at -30°C (22°F) or some other purchaser-specifiedtemperature, then cool the specimens to -10°C (14°F)below the specified bend temperature and hold for at leastone hour.

H4.2 Procedure A—The Mandrel Bend

H4.2.1 Calculate the required mandrel radius (R)using Equation (H1):

2t-

s(t)(57.3)R = (H1)

where: R = mandrel radius, t = effective strap thickness,and s = strain (deflection) in degrees per pipe diameter(°/PD).

Determine the effective strap thickness (t), which includesthe test specimen thickness and any curvature, by placingthe test specimen on a flat surface and measuring thethickness as shown in Figure H1.


RP0394-2002

Figure H1:Determination of Effective Strap Thickness

H4.2.2 If a mandrel of the calculated radius is notavailable, use the mandrel of the next smaller radius.

NOTE: Because the mandrel flexibility test is to deter-mine the total coating strain before “spring back,” donot use a smaller radius to achieve a “residual” (afterspring-back-bend radius). Using a smaller radius man-drel can cause the coated test specimen to be bentpast the required strain.

H4.2.3 Bend the test specimens over the radius sothat the uncoated side is in contact with the mandrel,completing the bend within 30 seconds of removal fromthe freezer or at the point the specimen reaches theproper bend temperature. The bend test shall take aminimum of 10 seconds for completion.

H4.2.4 Visually inspect the specimens for cracks,tears in the coating, and disbonding of the coating,after the test specimens have warmed to room temper-ature. The presence of any such defect within 2.5 mm(0.10 in.) of the strap edge does not constitute failure.The presence of strain marks alone does not constitutea failure.

H4.3 Procedure B—The Four-Point Bend

H4.3.1 Estimate the required bend using Equation(H1).

H4.3.2 Bend the test specimens using the four-pointapparatus so that the uncoated side is in contact withthe support pins. Complete the bend within 30 sec-onds. The bend test shall take a minimum of 10seconds for completion.

H4.3.3 Measure the residual bend radius bymatching the outer curve of the test specimen to thenearest arc from Figures H2, H3, H4, or H5.

H4.3.4 Visually inspect the test specimens for cracks,tears in the coating, and disbonding of the coating afterthe specimens have warmed to room temperature.The presence of any such defect within 2.5 mm (0.1in.) of the strap edge or within 12 mm (0.50 in.) of thesupport pins does not constitute a failure. The pres-ence of strain marks alone does not constitute a failure.

H4.4 Calculate the permanent (residual) strain usingEquation (H2):

2/tR)t)(3.57(

PD/−

=° (H2)

where t = “effective thickness” of coated strap, as defined inParagraph H4.2.1; R = bend radius of outer curve of testpanel.

Section H5: Report

H5.1 The following information shall be reported:

H5.1.1 Manufacturer, product code, batch number,and date tested;

H5.1.2 Pipe identification, if applicable; and

H5.1.3 Specimen effective thickness, angle of deflec-tion in degrees for each pipe diameter for passingbend, and test procedure used. Record permanent(residual) strain radius only for the four-point bend testmethod.


RP0394-2002


Figure H2:Radii 3.18-mm (0.125-in.) Increments

RP0394-2002


Figure H3:Radii in 3.18-mm (0.125-in.) Increments

RP0394-2002



RP0394-2002

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Appendix I—Impact Test

Section I1: Scope

I1.1 To provide a method for assessing the coating’sresistance to damage by impact.

Section I2: Equipment

I2.1 ASTM G 1411 Impact Tester, or equivalent

I2.2 DC holiday detector

I2.3 41-mm (1.6-in.)-radius mandrel hardened to 55 ±5HRC

Section I3: Test Specimen

I3.1 Laboratory-coated test specimens shall be approx-imately 100 mm (4 in.) square x 6.0 mm (0.25 in.) thick.Specimens shall be prepared and coated in accordancewith Paragraphs 4.3.2 and 4.3.3.

I3.2 Test-ring specimens shall be approximately 200 mm(8 in.) long x 25 mm (1.0 in.) wide x wall thickness. The200-mm (8-in.) dimension shall be parallel to the axis of thepipe.

Section I4: Procedure

I4.1 ASTM G 14 Impact Tester shall be modified as fol-lows: A tup (heavy metal object) that can accommodate a15.9-mm (0.625-in.)-diameter ball bearing shall be used.The tup shall have a hardness of 50 to 55 HRC.

I4.2 The modified impact tester shall be screwed to ablock of laminated wood. The wood block should measure

approximately 610 mm (24 in.) on each side and have a topfacing of hardwood.

I4.3 The impact test shall be carried out with 1.0-kg (2.2-lb) weight in a 1.0-m (39-in.) graduated slotted tube. Theball bearing shall be rotated every 10 impacts to a newlocation and replaced after 200 impacts.

I4.4 Using a flat anvil for laboratory-coated test speci-mens and the 41-mm (1.6-in.)-radius mandrel for test-ringspecimens, the weight shall be allowed to fall onto the tupsuch that the metal substrate is not deformed.

I4.5 Test temperature shall be 23 ±3°C (73 ±5°F).

I4.6 Each impact indentation on the test specimen shallbe checked for substrate exposure with a holiday detectorset at approximately 1,600 V or with a wet-sponge, low-voltage holiday detector.

Section I5: Report

I5.1 The following information shall be reported:

I5.1.1 Manufacturer, product code, batch number,and date tested;

I5.1.2 Pipe identification, if applicable;

I5.1.3 The maximum amount of energy (J or in.-lb)that the coating absorbed without substrate exposure;and

I5.1.4 Holiday detection voltage.

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Appendix J—Hot-Water Soak

Section J1: Scope

J1.1 To provide an accelerated assessment of thecoating’s adhesion to the substrate in a hot, wet environ-ment.

Section J2: Equipment

J2.1 Hot plate or oven capable of maintaining the testtemperature within ±3°C (±5°F) of specified value

J2.2 Plastic cylinder (such as in Appendix F)

J2.3 Utility knife

J2.4 Deionized or reverse osmosis water.

J2.5 For full immersion test, a pot and hot plate or heatedwater container capable of maintaining test temperatureswithin ±3°C (±5°F).

Section J3: Test Specimen

J3.1 Laboratory-coated test specimens shall be approxi-mately 100 mm (4 in.) square x 6.0 mm (0.25 in.) thick.Test-ring specimens shall be approximately 100 mm (4 in.)square x pipe wall thickness. For pipe smaller than 100-mm (4-in.) diameter, the length shall be approximately 100mm (4 in.).

J3.2 Laboratory-coated specimens shall be prepared andcoated in accordance with Paragraphs 4.3.2 and 4.3.3.


RP0394-2002

Section J4: Procedure

J4.1 For Cylinder Test

J4.1.1 Glue the plastic cylinder approximatelycentered onto test specimen.

J4.1.2 Pour approximately 350 mL of deionized orreverse osmosis water into the plastic cylinder.

J4.1.3 When testing specimens cut from pipe, use aheat-transfer medium (e.g., steel shot or grit) to provideuniform heating of the specimen. Use of a metal panpartially filled with the heat-transfer medium into whichthe test specimen is implanted is preferred. Place on ahot plate or in an oven to maintain the metal temp-erature at 66 ±3°C (150 ±5°F) for the 24-hour test.

J4.2 For Full Immersion Test

J4.2.1 Heat deionized or reverse osmosis water inthe container to 66 ±3°C (150 ±5°F).

J4.2.2 Place test specimen in the container. Be surethere is enough water in the container to keep the testspecimen completely immersed for the duration of thetest. Add hot deionized or reverse osmosis water asneeded.

J4.3 Water should be changed after each test and thecontainer cleaned.

J4.4 Evaluation Procedure

J4.4.1 After 24 hours, remove the test cell from thehot plate or oven and immediately drain the water anddismantle the test cell. While the sample is hot, use autility knife to scribe a rectangle approximately 25 x 12mm (1 x 0.5 in.) through the coating to the substrate.Air cool the sample to room temperature. The evalu-ation shall be performed within one hour of removalfrom the hot plate.

J4.4.2 The utility knife blade shall have a blade thick-ness no greater than 7.6 mm (0.30 in.). If possible,insert the utility knife 3.20 mm (0.125 in.) under thecoating at a corner of the scribed rectangle. Using alevering action, attempt to remove the coating. Afterthree attempts, if the coating cannot be easily removedin pieces the size of or larger than the inserted portionof the blade, rotate to the next corner. If the coatingcan be removed in pieces of coating the size of or lar-ger than the inserted blade, continue inserting the knife

and levering under the coating until either all of thecoating in the rectangle is removed or the coatingdemonstrates a definite resistance to the leveringaction. Coating removed by following the scribed lines,gouging, cutting, knife-point scrapes, or by forcing theknife blade through the coating shall not be consideredadhesion failure. Only coating removed by the leveringaction are considered to be adhesion loss.

J4.4.3 Rate the adhesion of the coating within therectangle as follows:

J4.4.3.1 Rating 1—After three attempts at eachcorner, the coating pieces removed are the samesize as, or smaller than, the size of the insertedknife point;

J4.4.3.2 Rating 2—Coating can be removed inchips that are slightly larger than the inserted knifepoint. Coating remains on 50% or more of thescribed area. In areas where coating has beenremoved by chipping, partial coating fragmentsmay remain firmly attached to the steel surfaceand shall be counted as part of the 50% or morewith coating;

J4.4.3.3 Rating 3—Coating can be removed inchips larger than the inserted knife point. Coatingremains on 20% or more of the scribed area. Inareas where coating has been removed by chip-ping, partial coating fragments may remain firmlyattached to the steel surface and shall be countedas part of the 20% or more of coating;

J4.4.3.4 Rating 4—The coating can be easilyremoved in strips or large chips considerably lar-ger than the inserted knife point and coatingremains on less than 20% of the rectangle, and;

J4.4.3.5 Rating 5—The coating in the rectanglecan be completely removed as a single piece or ina few large chips with little effort.

Section J5: Report

J5.1 The following information shall be reported:

J5.1.1 Manufacturer, product code, batch number,and date tested;

J5.1.2 Pipe identification, if applicable; and

J5.1.3 The rating obtained.


RP0394-2002

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Appendix K—Test for Interface Contamination of the Coating

Section K1: Scope

K1.1 To determine degree of visual contamination on pipesurface.

NOTE: This procedure does not detect the presence ofhydrocarbons, salts, or other nonvisual contaminants.

Section K2: Equipment

K2.1 Microscope

K2.2 Utility knife with sharp point

Section K3: Test Specimen

K3.1 Test specimens shall be approximately 200 mm (8in.) long x 25 mm (1.0 in.) wide x pipe wall thickness, withthe 200-mm (8-in.) dimension parallel to the axis of the pipe.

Section K4: Procedure

K4.1 Use the utility knife to remove an approximately 3 x19 mm (0.125 x 0.75 in.) piece of coating from the test

specimen subsequent to bending in accordance withAppendix G.

K4.2 Examine the metal interface side of the coating withthe microscope at 30X to 40X magnification, and rate thepercentage of interface contamination. The preferredmethod for determining area percentage is point counting,using an optical microscope of at least 30X to 40X magnif-ication and a lens reticle with a point-count grid containingat least 25 points.

Section K5: Report

K5.1 The following information shall be reported:

K5.1.1 Manufacturer, product code, batch number,and date tested;

K5.1.2 Pipe identification; and

K5.1.3 Percentage of interface contamination.

24 NACE InternationalISBN 1-57590-147-1

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