nace rp0394

Errata

Two typographical errors have been found in RP0394-94. Please mark these changes in your copy of the standard.

The note in Paragraph 6.1.1 should read:

NOTE: 2 pgkm’ of ferrous satt may adversely affect coating performance.

Paragraph 6.1.3 should read:

The surface of the pipe should be blast cleaned to NACE No. 2/SSPC-SP 10, “Near-White Metal Blast Cleaning,” or to IS0 8501 -1 Sa 2%.

COPYRIGHT NACE InternationalLicensed by Information Handling ServicesCOPYRIGHT NACE InternationalLicensed by Information Handling Services

NACE RP0374 9 4 m 6452782 0500785 683

lhNACE' NACE Standard RP0394-94 Item No. 21064

-

Informing the World on Corrosion Control

Standard Recommended Practice

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

External Pipe Coating

This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude 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, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infringement 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 this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE International assumes no responsibilityfor the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its governing procedures and policies which preclude the issuance 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 this standard prior to its use. This NACE International standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International standard are also responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory requirements prior to the use of this standard.

CAUTIONARY NOTICE: NACE International standards are subject to periodic review, and may be revised or withdrawn at any time without prior notice. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. Purchasers of NACE International standards may receive current information on all standards and other NACE International publications by contacting the NACE International Membership Services Department, P.O. Box 218340, Houston, Texas 7721 8-8340 (telephone +1 71 3/492-0535).

Approved October 1994 NACE International P.O. Box 218340

Houston, Texas 7721 8-8340 +1 71 31492-0535

Copyright O1 994, NACE International


NACE RP0394 94 b4529BL 0500786 5LT

RP0394-94

Foreword

This recommended practice presents guidelines for establishing minimum requirements to ensure proper application and performance of plant-applied, fusion-bonded epoxy coatings to the external surfaces of pipe. It was prepared by NACE Task Group T-1 OD-1 O, a component of Unit Committee T-1 OD on Protective Coating Systems, and is issued by NACE International under the auspices of Group Committee T-10 on Underground Corrosion Contro1.(’~2)

( I ) Wlth permlsslon of Canadian Standards Association (CSA), portions of this standard have been reproduced from CSA Standard 2245.20-M86, “External Fusion Bonded Epoxy Coated Steel Pipe,” (Copynght CSA, 1986). Copies of 2245.20-ME6 may be purchased from CSA, 178 Rexdale Boulevard, Toronto, Ontano, Canada, M9W 1R3. I*) With permission of the American Petroleum Institute, portions of this standard have been reproduced from API RP 5L7, ‘Recommended Practices for Unprimed Internal Fusion Bonded Epoxy Coating of Line Pipe,” Second Edition, June 30, 1988, American Petroleum Institute Publications and Distribution Section, 1220 L Street, NW, Washington, DC 20005.

This standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude 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, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infringement of Letters Patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures or materials.

NACE International i


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NACE RP0394 94 6452983 0500787 456 = RP0394-94

NACE International Standard .

Recommended Practice

Application. Performance. and Quality Control of Plant.Applied. Fusion-Bonded Epoxy

External Pipe Coating

Contents

1 . General ........................................................................................................................ 1 2 . Definitions .................................................................................................................... 1 3 . Reference Publications and Standards ....................................................................... 1 4 . Coating Material ........................................................................................................... 2 5 . Coating Performance ................................................................................................... 2 6 . Surface Preparation of Pipe ......................................................................................... 4 7 . Coating Application ...................................................................................................... 6 8 . Production Inspection and Testing .............................................................................. 6

11 . Marking ........................................................................................................................ 9 Appendix A-Infrared Spectroscopy Test Method ............................................................. 9 Appendix &Specific Gravity Determination ..................................................................... 9

9 . Repair .......................................................................................................................... 8 1 O . Handling, Storage, and Shipping ................................................................................. 8

Appendix C-Shelf Life Determination ............................................................................. 10 Appendix D-Gel Time Determination ............................................................................. 11 Appendix E-Glass Transition and Heat of Reaction Determination ............................... 11 Appendix F-Moisture Analysis Determination ................................................................ 12 Appendix G-Determination of Total Volatiles ................................................................. 13 Appendix H-Cathodic Disbondment Test ....................................................................... 14

Appendix J-Test for Porosity of the Coating .................................................................. 16 Appendix I-Chemical Resistance Test ........................................................................... 15

Appendix K-Flexibility Test .............................................................................................. 17 Appendix L-Impact Test .................................................................................................. 23 Appendix "Strain Polarization Test .............................................................................. 23 Appendix N-Hot Water Soak ........................................................................................... 24 Appendix O-Abrasion Test Method ................................................................................. 25 Appendix P-Test for Interface Contamination of the Coating ........................................ 25

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NACE RP0394 94 W h452981 0500788 392

RP0394-94

Section 1: General

1.1 This recommended practice presents guidelines for 1.3 This document suggests or describes methods for quali- establishing minimum requirements to ensure proper fying and controlling the quality of fusion-bonded epoxy pipe application and performance of plant-applied, fusion-bonded coatings, provides guidelines for their proper application, and epoxy coatings to the external surfaces of pipe. identifies inspection and repair techniques to ensure their

1.2 The function of such coatings isto prevent corrosion when used in conjunction with cathodic protection.

long-term performance.

Section 2:

2.1 Applicator - The organization responsible to the purchaser for the coating application.

2.2 Batch -The quantity of coating material produced during a continuous production run of not more than eight hours (h).

2.3 Coating material - Epoxy powder.

2.4 Coating - The protective film of coating after application to the substrate.

2.5 Cutback - The length of pipe left uncoated at each end for joining purposes (e.g., welding).

2.6 Holiday - A discontinuity in a protective coating that

Definitions

exhibits electrical conductivity when exposed to a specific voltage.

2.7 Inspector - The authorized agent of the purchaser.

2.8 Purchaser-Theownercompanyortheauthorizedagency that purchases the coated pipe.

2.9 Supplier - The manufacturer and/or distributor of the coating material and its authorized technician.

2.1 O MSDS - Material Safety Data Sheet.

2.1 1 PD - Pipe Diameter.

Section 3: Reference Publications and Standards

3.1 Where reference is made to other publications, such 3.1.4 NACE No. 2/SSPC-SP 10 (latest revision), “Near- references shall be considered to refer to the latest edition and White Metal Blast Cleaning” (Houston, TX: NACE Inter- any revisions thereto approved by the organization issuing national, and Pittsburgh, PA: SSPC). that publication. Some reference publications are supple- mented, qualified, or both, by specific requirementselsewhere 3.1.5 NACE Standard RP0490 (latest revision), “Holiday in this recommended practice; reference publications should Detection of Fusion-Bonded Epoxy External Pipeline therefore be applied only in the context of this recommended Coatings of 1 O to 30 Mils (0.25 to 0.76 mm)” (Houston, TX: practice. NACE International).

3.1.1 NACE Standard RP0169 (latest revision), “Control 3.1.6 SSPC-Vis 1 (latest revision), “Color Photographic of External Corrosion on Underground or Submerged Standards for Surface Preparation” (Pittsburgh, PA: Metallic Piping Systems” (Houston, TX: NACE Interna- SSPC). tional).

3.1.7 SSPC-SP 1 (latest revision), “Solvent Cleaning” 3.1.2 NACE Standard RP0675 (latest revision), “Control (Pittsburgh, PA: SSPC). of External Corrosion on Offshore Steel Pipelines” (Hous- ton, TX: NACE International). 3.1.8 ISO(4)8501 -1 (latest revision), “Preparation of Steel

Substrates Before Application of Paints and Related 3.1.3 NACE No. 1/SSPC(3)-SP 5 (latest revision), “White Products - Visual Assessment of Surface Cleanliness” Metal Blast Cleaning” (Houston, TX: NACE International, (Geneva, Switzerland: ISO). and Pittsburgh, PA: SSPC).

(’1 Steel Structures Paintlng Council (SSPC), 4516 Henry St., Suite 301, Pittsburgh, PA 15213-3728. (Il International Organization for Standardization (EO), 1 rue de Varembe, Case Postale 56, CH-1121 Geneva 20, Switzerland.

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NACE RP0374 74 = 6452783 0500787 229

RP0394-94

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

3.1.10 API RP 5L7 (latest revision), “Recommended Practices for Unprimed Internal Fusion Bonded Epoxy Coating of Line Pipe” (Washington, DC: API).

3.1.11 CAN/CSAZ245.20-M86, “External Fusion Bonded Epoxy Coated Steel Pipe” (Toronto, Ontario, Canada: CSA).

3.1 . I 2 ASTM(6) D 4060 (latest revision), “Standard Test Method for Abrasion Resistance of Organic Coatings by

the Taber Abraser” (Philadelphia, PA: ASTM).

3.1 . I 3 ASTM G 14 (latest revision), “Standard Test Method for Impact Resistance of Pipeline Coatings (Fall- ing Weight Test)” (Philadelphia, PA: ASTM).

3.1.14 ASTM G 17 (latest revision), “Standard Test Method for Penetration Resistance of Pipeline Coatings (Blunt Rod)” (Philadelphia, PA: ASTM).

3.1 .I5 ASTM G 95 (latest revision), “Standard Test Method for Cathodic Disbondment Test of Pipeline Coat- ings (Attached Cell Method)” (Philadelphia, PA: ASTM).

Section 4: Coating Material

4.1 Coating Supplier Information

4.1.1 The coating material supplier shall furnish to the purchaser and/or applicator the following information in a written form upon request:

4.1.1 .I Directions for handling and storage of the coating material,

4.1 . I .2 Specification of the basic physical properties and laboratory performance test results,

4.1 .I .3 Certification ofthedetermined physical properties of each batch of material,

4.1.1.4 Printed copy of infrared spectrum of the coating material (see Appendix A), and

4.1.1.5 Material Safety Data Sheets.

4.2 Handling of Coating Materials

4.2.1 Coating material batches shall be identified by a

4.3

batch coding system devised by the supplier. The batch code shall include a reference to the date of manufacture. Coating materials shall be shipped and stored under cover according to the supplier’s recommendations and in such a mannerthat contamination or adverse effects on application are avoided.

4.2.2 Shelf Life

Any batch of coating material that has exceeded the supplier’s recommended shelf life shall be subject to coating material verification tests (see Paragraph 8.3.2) prior to use.

Coating Material Properties

4.3.1 It is the supplier’s responsibility to perform the tests referenced in this section. The purchaser or applicator may also perform any or all of the referenced tests as part of a quality assurance program.

4.3.2 The coating material shall meet the value limits for the properties listed in Table 1.

Section 5: Coating Performance

5.1 Typical desired characteristics of applied coating are outlined in NACE Standard RPOl69.

5.2 The coating shall not deteriorate (¡.e., bum, blister, or char) more than 50 mm (2 in.) from the extreme edge of a weld or cut area when pipe is welded or torch cut.

5.3 Performance Testing

5.3.1 Qualification

It is the responsibility of the purchaser and/or coating applicator to qualify the coating material prior to coating application. Once qualification is established, further

qualification testing is not required unless the coating material, formulation, or location of manufacture changes. The supplier shall certify to the applicator and/or pur- chaserthe resultsof tests performed undersection 5.3for each qualified material.

5.3.2 Performance Testing Steel Panels

Test panels shall be hot-rolled carbon steel (AISI(’) 1020 or equivalent) and have dimensions in accordance with the referenced test method. The surface shall be blast cleaned using steel grit (G40,n 50 to 55 Rockwell C hardness [HRC]) to a surface profile of 38 to 1 O0 pm (1.5 to 4.0 mils), measured from peak to valley to one of the following standards:

(5J National Institute of Standards Technology (NIST), formerly the National Bureau of Standards, Gaithersburg, MD 20899. (‘)American Society for Testing and Materials (ASTM), 1916 Race St., Philadelphia, PA 19103.

American Iron and Steel Institute (AISI), 1133 15th St., NW, Washington, DC 20005-2701.

Automotive Engineers). (‘J SAE Standard J444 (latest revision), “Cast Shot and Grit Size Specifications for Peening and Cleaning, Recommended Practice” (Warrendale, PA: Society of

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NACE RP0394 9 4 = b45298L 0500790 T 4 0

5.3.2.1 NACE No. I/SSPC-SP 5 “White Metal Blast Cleaning.”

5.3.2.2 IS0 8501-1 Sa 3.

5.3.2.3 SSPC-Vis 1.

5.3.3 Coating of Test Panels

5.3.3.1 Coating application and curing shall be in accordance with the supplier’s recommendations. Application and curing temperatures shall not exceed 275°C (527°F).

RP0394-94

5.3.3.2 Coating thickness on the test panel shall be 360 * 50 pm (14 * 2 mils), measured by a coating thickness gauge calibrated against a NlST thickness standard (NIST-SRM 1363) that is within 20% of the specified coating thickness.

5.3.4 Performance of Laboratory-Coated Steel Panels

5.3.4.1 Testing

A coating shall be considered qualified when the results of a duplicate set of test panels meet the acceptance criterion for each test shown in Table 2.

TABLE 1 Epoxy Powder Properties

~

Property Value Limits Test Method

Density

Particle Size

Shelf Life

Per supplier’s specification f 3.5%

2% max. retained on 150 pm (1 O0 mesh) sieve; 0.1 Yo max. retained on 250 prn (60 mesh) sieve

Per supplier’s specification: per supplier’s recommended storage conditions

See Appendix B

See Appendix C

Gel Time Per supplier’s specification * 20% See Appendix D(*)

Cure Cycle

Glass Transition Temperatures

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

Per supplier’s specification See Appendix E(A)

H (Heat of Reaction) Per supplier’s specification See Appendix E(A)

Moisture Content@) 0.5% max. See Appendix F

Total Volatile ContenW 0.6% max. See Appendix G

CAI API RP 5L7 (see Paragraph 3.1.10 for complete reference). (W Either moisture or total volatile content may be determined at the supplier‘s dlscretion.



NACE RP0394 94 6 4 5 2 9 8 3 0500793 987

RP0394-94

TABLE 2 Qualification Requirements

No. of Test Acceptance Criteria Specimens Test Test Method

~~~

Cathodic Disbondment (24 h)

~~

See Appendix H(A) Max. radius: 8 mm

Cathodic Disbondment (28 d) Max. radius: 10 mm See Appendix H(A)

Chemical Resistance

Cross-Section Porosity

No blistering

Rating of 1 to 3

Rating of 1 to 4

See Appendix Us)

See Appendix J@)

See Appendix K@) Interface Porosity

Flexibility (2YPD at -18°C [O’F])

No cracks, tears, or delamination

See Appendix K(A)

Impact Resistance

Strain Polarization

1.5 J (13 in.-lb) min. See Appendix L(A) 3

3 No cracking See Appendix M(B) or delamination

Thermal Analysis (Differential Scanning Calorimetry)

Meets manufacturer’s specification

3 See Appendix E(A)

Hot Water Soak See Appendix N(*) A rating of 1 to 3, inclusive

3

Abrasion See Appendix O‘A) Max.: 300 mg

Less than 10%

3

3 Penetration ASTM G 17 at 93°C (200°F)

(*)API RP 5L7 (see Paragraph 3.1.10 forcomplete reference). , CAN/CSA 2245.20-M86 (see Paragraph 3.1.1 1 for complete reference).

Section 6: Surface Preparation of Pipe

6.1 This section emphasizes the importance of obtaining uncontaminated and adequately profiled pipe surface be- cause the condition of this interface will directly affect the coating’s performance.

6.1.2 Preheat is not required if pipe is visually free of moisture and is 3°C (5°F) above the dew point; otherwise, the pipe shall be uniformly preheated prior to blast cleaning to remove moisture from the surface. The preheat shall be sufficient to ensure that the pipe temperature is at least 3°C (5°F) above the dew point temperature during blast cleaning and inspection.

6.1.3 The surface of the pipe should be blast cleaned to NACE No. 2/SSPC-SP 1 O, “Near-White Metal Blast Clean- ing,” or to I S 0 8501 -1 Sa 2.

6.1.4 Surface profile shall be at least 38 pm (1.5 mils) from peaktovalley. Surface profile shall not exceed 100 pm (4 mils).

6.1.1 Bare pipe shall be supplied to the applicatoressen- tially free of salts, mill lacquer, oil, grease, or other deleterious deposits that would prevent meeting the acceptance criteria of Table 3 when coated as required by this recommended practice. The applicator shall sufficiently remove any remaining deleterious deposits from the surface to be coated to meet the acceptance criteria listed in Table 3.

NOTE: 2 mg/m2 of ferrous salt may adversely affect coating performance.



NACE RP0374 7 4 6452783 0500772 813

RP0394-94

6.1.5 Bevels, lands, and internal coatings shall be pro- joint of pipe. The disposition of any joint of pipe that exceeds tected from shotlgrit blasting and damage by impact or these limits shall be subject to agreement between the gouging. applicator and purchaser.

6.1.6 Residual products from blasting shall be suitably removed from the interior and exterior surfaces of the pipe.

6.1.7 Prior to coating, the cleaned pipe shall be visually inspected and imperfections that may cause holidays in the coating shall be removed by grinding in such a manner as to give a surface finish suitable for subsequent application of coating. The maximum grind area is 0.05 m2 (0.5 ftz) per location,andthemaximumtotalgrindareais0.2m2(2ft*)per

6.1.8 Disposition of pipe with imperfections that cannot be removed without encroaching upon minimum wall thickness orcausing interference with the normal production cycle shall be subject to agreement between applicator and purchaser.

6.1.9 Where approved or specified by the purchaser, additional surface treatments may be used prior to application of coating.

TABLE 3 Production Test Ring Requirements

Test

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No. of Test Test Type(*) Acceptance Criteria Specimens

~

Test Method

Cathodic Disbond- A Max. radius: 12 mm(e) 1 ment (24 h)

Flexibility (1.5"/PD A No cracks, tears, or 3 Permanent Strain) delamination

Hot Water Soak A Rating of 1 to 3, inclusive

Interface B Max.: 30% Contamination

Cross-Section B Rating of 1 to 3, Porosity inclusive

Thermal C T, of 5"C, max. Characteristics or 95% conversion H

minimum

See Appendix H(C)

See Appendix K(cvD)

1 See Appendix N(C)

1 See Appendix P(E)

1 See Appendix J(E)

1 See Appendix ECC)

Impact Resistance C 1.5 J minimum 1 See Appendix L(') (13 in.-lbs.)

(*) Failure to meet the acceptance criteria for Type A tests shall be grounds for rejection of all plpe coated after the previous acceptable test result and prior to the next acceptable test result. Additional Type A testing of the affected day's production may be conducted in an attempt to reduce the amount of rejected pipe. Failure to meet the acceptance criteria for Type B or C tests shall be grounds for requiring changes to the application process parameters. Type C tests are required only when specified by purchaser. NOTE: The purchaser may require that the applicator limit the application process until the cause of the failure has been remedied. (B) Disbondment radli greater than 8 mm generally Indicate that problems exist in either process control or powder quality; the user may wish to specify a maximum cathodic disbondment test radius of less than 12 mm. IC) API RP 5L7 (see Paragraph 3.1.10 for complete reference). (D) Purchaser may specify more stringent flexibility requirements for specific applications.

CAN/CSA 2245.20-M86 (see Paragraph 3.1.1 1 for complete reference).



NACE RP0374 74 6452783 0500773 75T

RP0394-94

Section 7: Coating Application

7.1 This section provides information on application tech- accordance with the coating manufacturer’s recommen- niques for obtaining optimum performance of fusion-bonded dations. epoxy pipe coatings.

7.1 -4 The minimum and maximum coating thicknessshall 7.1 . I When changing from one coating manufacturer or be specified by the purchaser. The differential between product to another, care should be taken to minimize minimum and maximum thickness shall not be less than cross-contamination of coating materials. 100 Fm (4 mils).

7.1.2 Application and curingtemperatures of the external 7.1.5 To meet the acceptance criteria listed in Table 3, the pipe surface shall be selected by the applicator, shall not specified minimum thickness should not be less than 300 exceed 275°C (527”F), and shall be in accordance with pm (12 mils). the coating supplier’s recommendations.

7.1.3 Cure schedule shall be selected by the applicator chaser. to ensure adequate cure of the coating and should be in

7.1.6 The cutback limits shall be specified by the pur-

Section 8: Production Inspection and Testing

8.1 Plant Access 8.3 Production Tests

The inspector representing the purchaser shall have free access, while work on the contract of the purchaser is being performed, to all parts of the applicator’s plant concerned with the storage, application, testing, and handling of the epoxy powder and coating of the purchaser’s pipe. The inspection should be performed by a person qualified by experience and training in coating inspection methods. The applicator shall afford the inspector, without charge, inspection facilities to satisfy the inspector that the coating is being applied in accordance with the requirements of this recommended practice. All inspections shall be made at the place of application prior to shipment of the coated pipe, unless otherwise specified by the purchaser, and shall be conducted so as not to interfere unnecessarily with the operation of the plant.

8.2 Inspection Notice

Where the inspector representing the purchaser desires to inspect the coated pipe or witness the tests, the applicator shall give reasonable notice of the time at which the application or tests are to be made.

8.3.1 The applicator shall have suitable equipment at the plant to perform Type A and B tests as required by Table 3.

8.3.2 Verification of Epoxy Powder Quality

8.3.2.1 The minimum testing frequencyshall be one sample on every shipment of epoxy powder re- ceived. Tests conducted and the acceptance requirements shall be in accordance with Paragraphs 8.3.2.2 and 8.3.2.3. On stock-stored materials, gel time tests only shall be conducted prior to each pipe coating order.

8.3.2.2 Laboratory-coated test specimens shall be prepared at the proposed plant application temperature in accordance with the requirements of Para- graphs 5.3.2 and 5.3.3.

8.3.2.3 The tests to be conducted and the acceptance criteria are shown in Table 4.



RP0394-94

TABLE 4 In-Plant Verification of Epoxy Powder Quality

No. of Test Test Acceptance Criteria Specimens Test Method

Cross-Section Porosity Rating of 1 to 3, inclusive

Interface Porosity Rating of 1 to 4, inclusive

Flexibility No cracks, tears, or (2VPD Permanent Strain) delamination

1 See Appendix J(A)

1 See Appendix J(A)

3 See Appendix K@)

Gel Time Per supplier’s 1 See Appendix D@) specification * 20%

‘*) CAN/CSA 2245.20-M86 (see Paragraph 3.1.1 1 for complete reference). ln) API RP 5L7 (see Paragraph 3.1.10 for complete reference).

8.3.3 In-line Inspection and Measurement 8.3.3.6 Curing

8.3.3.1 General

The inspection and measurements required by Para- graphs 8.3.3.2 through 8.3.3.8 shall be made by the applicator underthe supervision of a person qualified by experience and training in coating inspection methods.(g)

8.3.3.2 Surface Finish

Surface finish shall be monitored hourlytodetermine compliance with Paragraph 6.1.3.

8.3.3.3 Surface Profile

At least once perfour hours of production the surface profile shall be measured using a replicating film or equivalent. The profile shall be within the limits specified in Paragraph 6.1.4.

8.3.3.4 Surface Inspection

Each cleaned pipe shall be visually inspected for surface defects and surface imperfections that may cause holidays in the coating. Surface imperfections shall be removed by grinding or other suitable means in accordance with Paragraphs 6.1.7 and 6.1.8. Pipe containing surface defects shall be rejected or repaired at the purchaser’s option.

The curing temperature and the time interval between application and quenching shall be controlled in accordance with Paragraphs 7.1.2 and 7.1.3.

8.3.3.7 Coating Thickness

8.3.3.7.1 The coating thickness shall be measured at three locations on each pipe using a coating thickness gauge calibrated at least once per eight-hour shift, in accordance with the requirements of Paragraph 5.3.3.2. The range of measured thickness shall be recorded.

8.3.3.7.2 If any individual measured thickness value is less than the specified minimum value of Paragraph 7.1.4, the coating thickness shall be measured at l - m (34) intervals along the pipe length. The average of these measurements shall exceed the specified minimum value and no individual value shall be more than 50 pm (2 mils) below the specified minimum value. The average and minimum thickness shall be recorded.

8.3.3.7.3 Pipe failing to meet the requirements of Paragraph 8.3.3.7.2 shall, at the purchaser’s option, be accepted, repaired, or recoated.

8.3.3.8 Holiday Inspection

8.3.3.5 Application Temperature 8.3.3.8.1 General

The surface temperature of the pipe immediately prior to epoxy powder application shall be monitored and controlled within the limits agreed upon by the applicator, the purchaser, and the coating supplier.

8.3.3.8.1.1 The entire coated surface of each length of pipe shall be inspected with a holiday detector in accordance with NACE Standard RP0490.

te) NACE lnternatlonal offers coating Inspection certification and training programs. Contact the NACE International Membership Services Department for information.



NACE RP0394 9 4 h452981 0500795 522

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8.3.3.8.1.2 Inspection is best performed when the temperature of the coating is less than 90°C (194°F). Higher temperatures may be acceptable as long as the holiday detector does not create excessive holidays.

8.3.3.8.2 Acceptance Criteria

8.3.3.8.2.1 Pipe containing holidays shall be repaired or recoated in accordance with the requirements of Section 9.

8.3.3.8.2.2 The maximum number of re- pairs is:

8.3.4 Production Test Rings

8.3.4.1 Test rings shall be a minimum of 300 mm (12 in.) long.

8.3.4.2 For each pipe size (distinct combination of diameter and wall thickness), the minimum frequency of obtaining test rings should be one sample for each of the following lots or fraction thereof:

8.3.4.2.1 The first 300 m (1,000 ft) of pipe coated,

8.3.4.2.2 The next 6,000 m (20,000 ft) of pipe coated,

One per 1 m (3 ft) of pipe length, for 8.3.4.2.3 The next I 0,000 m (33,000 ft) of pipe pipe sizes smallerthan 360 mm (1 4 in.) coated, and outside diameter (OD), or

One per 2.3 m2 (25 ft2) of surface area, ft) of pipe coated. for 360 mm (14 in.) OD and larger pipe sizes. 8.3.4.3 The tests to be conducted and the accep-

8.3.4.2.4 Each subsequent 10,000 m (33,000

tance criteria for test rings are shown in Table 3.

Section 9: Repair

9.1 All coating defects should be repaired using materials that are compatible with and will adhere well to the fusion-bonded epoxy powder coating and are approved by the purchaser.

9.2 Repair materials normally consist of:

9.2.1 Heat melting sticks, and

9.2.2 Two-part liquid epoxy or equivalent.

9.3 Patched areas should overlap the parent coating a minimum of 13 mm (0.5 in.). The surface to be repaired should be suitably prepared to ensure adhesion of the patch material. Minimum thickness of the repaired coating shall be in accordance with Paragraph 7.1.4.

9.3.1 Areas25 mm (1 in.) in diameterandsmallershall be patched with the supplier's recommended hot-melt patch stick, two-part epoxy, or equivalent.

9.3.2 Areas greater than 25 mm (1 in.) in diameter and less than 260 cm2 (40 in.*) shall be patched with the powdersupplier's recommendedtwo-partepoxyorequiva- lent.

9.4 For stripping, pipe shall be heated to a temperature not exceeding 275°C (527OF) in order to soften the coating to permit removal by scraping, followed by abrasive blasting.

Section 10: Handling, Storage, and Shipping

10.1 After being externally coated and cured, the pipe should 10.4 When loading or storing pipe, each pipe should be be sufficiently cooled to permit handling. protected using full-encirclement separators. The separators

shall be located within 0.9 m (3 ft) of the pipe ends and at one 10.2 Coated pipe shall be handled in such a way that damage or more approximately equidistant intermediate location(s) to the pipe and/or coating is avoided. Equipment used in the less than 5.5 m (18 ft) apart. Separators near the pipe ends handling and storage of coated pipe shall be appropriately shall not interfere with the readability of identification mark- padded. ings.

10.3 Pipe or coating that is damaged during processing shall be repaired in accordance with the requirements of the applicable pipe specification or standard or Section 9 of this recommended practice.



NACE RP0394 94 6452983 O500796 469

RP0394-94

Section 11 : Marking

11.1 As specified, the following identification markings shall 11.1.4 Coating material identification, and be placed on the coating:

11.1.5 Additional markings as desired bythe applicatoror 11.1.1 Applicator’s name or mark (work order number), requested by the purchaser (purchase order number).

11.12 Markings required by the applicable pipe specification or standard (grade, weight, manufacturer, etc.),

11.1.3 Date of coating application,

Appendix A Infrared Spectroscopy Test Method

Section A l : Scope Section A4: Report

A l .1 To provide documentation of the general composition of A4.1 The following information shall be reported: the coating material.

A4.1.1 Manufacturer, product code, batch number, and Section A2: Equipment date tested,

A2.1 Infrared spectrophotometer and accessories. A4.1.2 Printed copy of spectrum, and

Section A3: Procedure A4.1.3 Spectrophotometer type.

A3.1 Prepare and evaluate sample in accordance with spectrophotometer manufacturer’s instructions.

Appendix B Specific Gravity Determination

Section B1 : Scope Section 83: Procedure

B1.l To determine the specific gravity of a coating material. 83.1 Procedure A - Liquid Displacement Method

B1.2 Two procedures are specified: the liquid displacement B3.1.1 This method covers the determination of the method and the pycnometer method. The procedure used density of coating material by the liquid displacement must be designated on the supplier’s data sheet. Whether the method. test is run on powder or cured coating must also be specified.

B3.1.2 All apparatus, samples, water, and mineral spirits Section 82: Equipment must be conditioned to room temperature for a minimum

of two hours prior to testing.

83.1.3 Accurately weigh the flask and record the weight, B2.1 Volumetric flask, 100 mL

B22 Balance accurate to 0.1 g which is designated W,.

B2.3 Mineral spirits (aliphatic Hydrocarbon BP) having den- 83.1.4 Add approximately 20 g of coating material to the sity of D, flask and weigh the flask with coating material. This

weight is designated WFp.



~~

NACE RP0394 9 4 b45298L 0500797 3T5 = RP0394-94

B3.1.5 Add sufficient mineral spirits to cover and wet the coating material. Place the stopper on the flask and agitate it for several minutes in order to ensure that there are no air pockets or lumps of dry coating material. Wash the stopper and walls of the flask with mineral spirits until they are free of any coating materials and fill the flask to the 1 OO-rnL level. Weigh the flask, coating material, and liquid together to obtain W,,,.

83.1.6 Calculate the density of the coating according to the following equation:

83.2 Procedure B - Pycnometer Method

83.2.1 This procedure determines the density of the powderthat can be expressed in units of g/cm3. Specific gravity is dimensionless; however, the numbers are the same.

B3.2.2 Determine the density of the coating material using an air-comparison pycnometer or equivalent, in accordance with the instrument manufacturer's instructions.

density = wFf - NOTE: Both specific gravity and density vary with tem-

( - (1) perature. The differences that may be observed within normal room temperature ranges are within the accuracy of the method. 100 -

DL

B3.1.7 Clean and dry the flask, fill the flask with distilled Section 84: Report water to the 100 mL level, and weigh. This weight is designated W,. 84.1 The following information shall be reported:

B3.1.8 Clean and dry the flask, fill with mineral spirits to B4.1.1 Manufacturer, product code, batch number, and the 100 mL level, and weigh it to determine the weight date tested, and (WFL) of the mineral spirits used.

B3.1.9 Calculate the specific gravity of the coating dure B). material according to the following equation:

B4.1.2 Specific gravity (Procedure A) or density (Proce-

Appendix C Shelf Life Determination

Section C l : Scope Evaluate the 24°C (75°F) sample monthly and the 43°C (109OF) sample weekly. To evaluate the samples, look for

C l .I To estimate the shelf life of coating materials evidence of hard caking of the coating material in the jar. Remove a portion of sample and measure the gel time (see

Section C2: Equipment Appendix D).

C2.1 0.5-L (pint) glass jars and lids C3.2 A 30% reduction in gel time indicates that the shelf life

C2.2 Oven

C2.3 Gel time apparatus

has been exceeded.

Section C4: Report

C4.1 The following information shall be reported: Section C3: Procedure

C4.1 .I Manufacturer, product code, batch number, and C3.1 Record the initial gel time (see Appendix D) of the date tested, and coating material. Place a sample of the coating material into each of two jars and screw on the lids. Store one sample at C4.1.2 Shelf life in days for each test temperature. 24°C (75°F) and the other sample in an oven at 43°C (1 09°F).



NACE RP0394 9 4 bY5298L 0500798 231

RP0394-94

Appendix D Gel Time Determination

Section Dl: Scope 650 mm' (1 in.2) to a uniform thickness. Start the timer as soon as the coating material becomes molten. Stir the

D I .I To determine the gel time of a coating material. coating with a stiff wire or spatula, and stop the watch when the coating becomes an unstirrable gelatinous

D I .2 Two procedures are allowed for gel time determination; product. The elapsed time is the gel time. the procedure used must be reported on the supplier's data sheet. Tests shall be made in triplicate and averaged. D3.2 Procedure B

Section D2: Equipment D3.2.1 Adjust and stabilize the hot plate to 204 f3"C (400 f 5°F). Set the draw-down bar on the hot plate, quickly

D2.1 Hot plate place a sample of coating material in front of the blade and draw a continuous film 300 to 350 pm (0.012 to 0.014 in.)

D2.2 Stop watch or electric timer (0.1-second interval) thick across the surface of the hot plate. Start the timer. Applyingonlylightpressureonthespatula,drawitthrough

D2.3 Spatula the melted powder at short intervals.

02.4 Draw-down bar (gapdepth approximately 600 pm [0.024 in.])

D2.5 Stiff wire

Section D3: Procedure

D3.1 Procedure A

, D3.1.1 Gel time shall be determined by placing approximately 1 g of coating material on a hot plate stabilized at 204 + 3°C (400 f 5°F). Use a spatula to coat out at least

D3.2.2 The gel time is the length of time from when the film is applied until the spatula rides up on the gelled surface.

Section 04: Report

D4.1 The following information shall be reported:

D4.1.1 Manufacturer, product code, batch number, and date tested, and

D4.1.2 Gel time in seconds and procedure used.

Appendix E Glass Transition and Heat of Reaction Determination

Section E l : Scope Section E3: Procedure

EI .I To determine the glass transition temperature (Tg) and the amount of exothermic heat of reaction (AH) of epoxy powder or fusion-bonded epoxy pipe coating.

E I .2 Round-robin comparisons between laboratories have resulted in significant variation in all parameters measured. Achieving comparable results between laboratories will require strict compliance with this test procedure followed by laboratory comparison testing.

Section E2: Equipment

E3.1 Obtain a 10 f 1 -mg sample of epoxy powder or coating as applicable.

E3.2 Place the sample in a preweighed aluminum pan and put cover in place. Crimp the cover into place with the encapsu- lating press and obtain the sample weight by subtracting pan and cover weight from the total weight. Place a small vent hole in the lid without damaging the pan.

E3.3 Place sample and reference (as suggested by the instrument supplier) in the DSC cell.

E2.1 Differential scanning calorimeter(DSC) and accessories E3.4 Use an inert gas, such as dry nitrogen, to purge the cell.

E2.2 Analytical balance accurate to 0.1 mg

E2.3 Knife or file

E3.5 Heat the sample to just beyond the glass transition temperature (T o for coating material; Tg, for coating) using a heating rate of !?O% (36"F)/min. Do not record this scan.

NACE Internation.al 11


RP0394-94

E3.6 Immediately after heating, cool the DSC to 20°C (68°F) tangent to the curve at the inflection point. or below.

E3.7 Using a programmed rate of 20°C (36"F)/min, heat the sample from 25°C (77°F) to a point about 25°C (45°F) beyond the end of the expected exothermic reaction region as determined from a coating material (powder) scan. Record this scan. Name the glass transition measured in this scan T,, if the sample is a coating chip, or TgO if the sample is coating material (powder).

E3.8 As in Paragraph E3.6, cool the DSC cell to 20°C (68°F) or below and proceed to the next run immediately.

E3.9 Heat the sample at 20°C (36"F)/min, recording the second scan from 25°C (77°F) to a point about 25°C (45°F) past the glass transition. Name the glass transition measured in this scan Tg, if the sample is a coating chip or TgF if the sample is the coating material (powder).

Section E4: Calculations

E4.1 The Tg is taken as the point of intersection of the extrapolated baseline at the low-temperature end and the

E4.2 Calculate the residual exothermic heat of reaction (AH,) following the instructions provided by the manufacturer of the DSC equipment.

E4.3 'Tg = Tg, - Tg, (3)

Section E5: Report

E5.1 The following information shall be reported:

E5.1 .I Manufacturer, product code, batch number, and date tested,

E5.1.2 Pipe sample identification, if applicable,

E5.1.3 Report TgO, TgF, and AH for coating material (powder); report Tg,, Tg2, AT,, and AH, for coating, includ- ing units, and

E5.1.4 Type of apparatus used.

Appendix F Moisture Analysis Determination

Section F1: Scope F2.1.9 Plastic syringe (10 mL)

F I .I To determine moisture content of epoxy powder by direct F2.1.10 Automatic buret (50 rnL) titration with Karl Fischer reagent to an electrometric endpoint.

Section F2: Equipment and Reagents F2.2 Reagents

F2.2.1 Chloroform (trichloromethane) F2.1 Equipment

F2.1.1

F2.1.2

F2.1.3

F2.1.4

F2.1.5

F2.1.6

F2.1.7

F2.1.8

Aquameter apparatus

Lab mill

Analytical balance

15-mL serum bottle and cap

Spatula

Metal pipette holder - 1 mL

l-mL syringe

110-mm (4 -in.) hypodermic needle

F2.2.2 Generator solution

F2.2.3 Vessel solution (Parts A and B)

F2.2.4 Neutralizing solution

F2.3 Safety Precautions

F2.3.1 Karl Fischer reagent is toxic. During handling of the solutions, avoid breathing of the vapors, and perform all operations in a well-ventilated area.

F2.3.2 Follow the MSDS instructions for personal protection requirements.



RP0394-94

Section F3: Procedure F4.1 .I Manufacturer, product code, batch number, and date tested, and

F3.1 Run duplicate samples following the instrument manufacturer's instructions. F4.1.2 Percent moisture content for each sample and the

average moisture content. Section F4: Report

F4.1 The following information shall be reported:

Appendix G Determination of Total Volatiles

Section G1 : Scope G3.6 Condition the sample in desiccator for 20 min before weighing to determine the weight loss.

G3.7 Place the sample in the vacuum oven at 50°C (122°F) Section 62: Equipment and vacuum of 710 mm (28 in.) mercury for one additional

hour.

G3.8 Determine the weight loss, in accordance with Para-

GI . I To determine volatiles in the coating material.

G2.1 Analytical balance having weighing precision of 0.1 mg

G2.2 Vacuum oven controllable within f 3°C (& 5°F) graph G3.6. I

G2.3 Sample container

G2.4 Desiccator

G3.9 Continue the test until the sample reaches constant weight (¡.e., zero weight loss between two successive weighings).

Section G3: Procedure Section G4: Calculations

G3.1 Place the sample container in the vacuum oven at 50°C G4.1 Calculate the percent total volatiles as follows: (122°F) at minimum vacuum of 710 mm (28 in.) of mercuryfor a period of two hours. %TV= ( PWP - PDP )loo (4)

G32 Place the sample container in the desiccator for 20 min to allow return to room temperature.

where: PWP = pan plus wet coating material, PDP = pan plus G3.3 Determine the tare weight of the sample container. dry coating material, and EP = weight of empty pan.

G3.4 Place the coating material sample (approximately 1 O g) Section G5: Report in the sample container and reweigh accurately to determine the weight of the sample. A minimum of two samples per batch G5.1 The following information shall be reported: is recommended.

G35 Place the sample container with coating material in the date tested, and vacuum oven at 50°C (122°F) and vacuum of 71 O mm (28 in.) of mercury for a period of two hours. G5.1.2 The percent total volatiles for each sample and

PWP - EP

G5.1.1 Manufacturer, product code, batch number, and

the average total volatiles.



NACE RP0374 94 = 6452983 0500803 65b = R PO394-W

Appendix H Cathodic Disbondment Test

Section H l : Scope

HI . I This test provides an assessment of the resistance of the coating to disbondment when subjected to cathodic protection. This test is similar to ASTM G 95. This procedure covers both the 28-day qualification test and the 24-hour qualification and production test.

Section H2: Equipment

H2.1 DC power supply unit

H2.2 Platinum or platinum-coated anode wire

H2.3 Electrolyte solution consisting of 3 wt% sodium chloride (NaCI) in distilled water

H2.4 Plastic cylinder 90 mm (3.5 in.) diameter, 1 O0 mm (4 in.) long

H25 High-impedance voltmeter

H2.6 Hot plate or oven capable of maintaining f 3°C (f 5°F)

H2.7 Calomel reference electrode

H2.8 Utility knife

Section H3: Test Specimen

H3.1 Laboratory-Coated Specimen

H3.1.1 The minimum dimensions of the specimen shall be 100 mm (4 in.) square x 6 mm (0.25 in.) thick. The specimen shall be prepared and coated in accordance with Paragraphs 5.3.2 and 5.3.3 of this recommended practice.

H3.2 Test-Ring Specimen

H3.2.1 The test specimen shall be a 100-mm (4417.) square segment cut from the test ring.

H3.3 Drill a 3-mm (1/84n.)-diameter holiday in the coating at the center of the specimen.

H3.4 Glue a plastic cylinder onto the specimen with the holiday at the center of the cylinder.

Section H4: Procedure

H4.1 Pour approximately 350 mL of electrolyte into the plastic cylinder.

H4.2 When testing specimens cut from pipe, a heat-transfer medium (e.g., steel shot or grit) shall be employed to provide uniform heating of the specimen. Use of a metal pan partially filled with the heat-transfer medium into which the specimen is

implanted is preferred. Place on a hot plate or in an oven to maintaintheelectrolytetemperatureat66f3"C(150f5"F)for the 24-hour test. The thermometer shall be immersed and resting on the sample. Run the 28-day test at 20 f 3°C (68 f 5°F).

H4.3 Connect the negative lead from the power supply to the specimen and the positive lead to the anode after the test temperature is reached.

H4.4 Turn on the power supply and apply voltage to the test specimen: negative 3.5 V with respect to the calomel reference electrode for the 24-hour test and negative 1.5 V for the 28-day test.

H4.5 Monitorthe voltage, temperature, and electrolyte level at the start, and at every 24-hour interval thereafter. For the 28- day test, the electrolyte level need not be monitored on weekends or other nonworking days if a cover plate is loosely fitted over the test cell. Add distilled water as required to maintain the electrolyte level.

H4.6 Evaluation Procedure

H4.6.1 After 24 hours, remove the 24-hourtest cell from the hot plate or oven, immediately drain the electrolyte from the cell, rinse with tap water, dismantle the test cell, and air-cool the sample to room temperature. The evaluation shall be performed within one hour of removal from the hot plate. After 28 days, remove the 28-day test cell using the same procedure.

H4.6.2 Using a utility knife, make radial cuts from the edge of the holiday outward through the coating to the substrate. The radial cuts shall be at least 20 mm (0.8 in.) in length.

H4.6.3 lnsertthe blade of a utility knife underthe coating. Using a prying action, chip off the coating. Continue until the coating demonstrates a definite resistance to the prying action.

H4.6.4 Measure the radius of the disbonded area from the holiday edge along each radial cut and average the measured results.

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 Average disbonded radius.



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NACE RP0394 9 4 6452981 0500802 5 9 2 m

RP0394-94

Appendix I Chemical Resistance Test

Section Il : Scope Section 14: Procedure

I I .I To evaluate the resistance of coating to various reagents. 14.1 Add sufficient reagent to the jar so that half the length of the test specimen is immersed in the medium.

14.2 Place thevented lid on the jarand ensurethatthe medium Section 12: Equipment

12.1 1 -L (1 -qt) glass jars and vented lids level remains constant for 90 days at 20 & 3°C (68 & 5°F).

12.2 Test media as shown in Table II

12.3 Follow the MSDS instructions for each reagent for required personal protection.

Section 13: Test Specimen

13.1 Each test specimen shall be approximately 200 mm (8 in.) long x 25 mm (1 .O in.) wide x 6 mm (0.25 in.) thick. All surfaces of the test specimen shall be coated in accordance with Paragraphs 5.3.2 and 5.3.3 of this recommended practice.

14.3 After 90 days of immersion, remove the test specimen and examineforbleaching, swelling, softening, blisters, cracks, delamination, and loss of adhesion.

Section 15: Report

15.1 The following information shall be reported:

15.1.1 Manufacturer, product code, batch number, and date tested, and

15.1.2 Condition of the coating for both liquid and vapor- phase portions after 90-day immersion for each test reagent.

TABLE Il Test Media

Test Medium Concentration PH

HCI in water* HNO, in water' NaCl + H,SO, in water*

NaCl in water' Distilled water* NaOH in water*

........................

........................

100,000 ppm chloride 10% 100% 5%

2.5 to 3.0 2.5 to 3.0

3.0

* Distilled or deionized



RP0394-94

Appendix J Test for Porosity of the Coating

Section J1: Scope dance with Paragraphs 5.3.2 and 5.3.3 of this recommended practice. Specimens from test rings shall be approximately

J1.l To determine the degree of porosity or voids in the 200 mm (8 in.) long x25 mm (1 .O in.) widex pipe wall thickness, applied coating with the 200-mm @-in.) dimension parallel to the axis of the

pipe. Section 52: Equipment

Section 54: Procedure J2. 1 Microscope

J4.1 Cool the test specimen to a temperature low enough to J2.2 Bench vise or guided-bend jig allow removal of the coating when bent over a sharp radius.

J2.3 Dry ice or freezer

J2.4 Utility knife

Section J3: Test Specimen

J4.2 Pry off a piece of coating from the bent test specimen and examine the coating for porosity at 30X to 40X magnification.

J4.3 Rate the cross-section porosity in the coating bycompar- ing it to the photographs shown in Figure JI .

J3.1 Laboratory-coated test specimens shall be approxi- J4.4 Rate the interface porosity by comparison with Figure 52. mately200 mm (8 in.) long x25 mm (1 .O in.) widex 6 mm (0.25 in.) thick. Specimens shall be prepared and coated in accor-

Rating 1 Rating 1 O

Rating 2 Rating 2

Rating 3 Rating 3 O 0 o "O o

Rating 4

Rating 5

Figure J1 - Examples of Cross-Section Porosity Figure J2 - Examples of Interface Porosity



NACE RP0394 9 4 = 6452983 0500804 365

RP0394-94

~

Appendix K Flexibility Test

Section K1: Scope

K1.l To evaluate flexibility of the coating for field bending

Section K2: Equipment

K2.1 Press

K2.2 Bending mandrels of fixed radii (Procedure A) or four- point bending apparatus (Procedure B)

K2.3

K2.4

K3.1

Freezer

Microscope

Section K3: Test Specimen

Laboratory-Coated Specimen

Each specimen shall be approximately 200 mm (8 in.) long x 25 mm (1 .O in.) wide x 6 mm (0.25 in.) thick. The specimen shall be prepared and coated in accordance with Paragraphs 5.3.2 and 5.3.3 of this recommended practice.

K3.2 Test-Ring Specimen

Each specimen shall be approximately 200 mm (8 in.) long x25 mm (1 .O in.) wide x pipe wall thickness, with the 200-mm @-in.) dimension parallel to the axis of the pipe.

Section K4: Procedure

K4.1 Ensure that the specimen edges have all stress raisers removed and that substrate is exposed along the edges. Place the test specimens in the freezer, cool them to -18°C (0°F) and hold for one hour.

K4.2 Procedure A - The Mandrel Bend

K4.2.1 Calculate the required mandrel radius (R) using the following formula:

(57.3) ( t ) t R = " (5) S 2

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

BEND CURVATURE

ORIGINAL PIPE CURVATURE

EFFECTIVE STRAP THICKNESS THICKNESS

STRAP

Determine the effective strap thickness (t), which includes the specimen thickness and any curvature, by placing the specimen on a flat surface and measuring the thickness as shown in Figure K1.

K4.2.2 Where a mandrel of the calculated radius is not available, the mandrel of the next smaller radius shall be used.

K4.2.3 Bend the test specimens over the radius so that the uncoated side is in contact with the mandrel, complet- ing the bend within 30 seconds. The bend test shall take a minimum of 10 seconds for completion.

K4.2.4 Measure the residual bend radius by matching the outer curve of the test specimen to the nearest arc from Figures K2, K3, K4, or K5. Visually inspect the specimens for cracks, tears in the coating, and disbonding of the . coating after the specimens have warmed to room temperature. The presence of any such defect within 2.5 mm (0.1 in.) of the strap edge does not constitute failure. The presence of strain marks alone does not constitute a failure.

K4.3 .Procedure B - The Four-Point Bend

K4.3.1 Estimate the required bend using the equation in K4.2.1.

K4.3.2 Bend the test specimens using the four-point apparatus so that the uncoated side is in contact with the support pins. Complete the bend within 30 seconds. The bend test shall take a minimum of 1 O seconds for completion.

K4.3.3 Measure the residual bend radius by matching the outer curve of the test specimen to the nearest arc from Figures K2, K3, K4, or K5.

K4.3.4 Visually inspect the specimens for cracks, tears in the coating, and disbonding of the coating after the specimens have warmed to room temperature. The presence of any such defect within 2.5 mm (0.1 in.) of the strap edge or within 12 mm (0.5 in.) of the support pins does not constitute a failure. The presence of strain marks alone does not constitute a failure.

K4.4 Calculate the permanent (residual) strain with the following equation:

where t = "effective thickness" of coated strap, as defined in K4.2.1; R = bend radius of outer curve of test panel.

Figure K1 Determination of Effective Strap Thickness



RP0394-94

Section K5: Report K5.1.2 Pipe identification, if applicable, and

K5.1 The following information shall be reported: K5.1.3 Specimen effective thickness, permanent (residual) strain radius, ande of deflection in degrees per pipe d’iameterforpassingbend, and test procedure used.

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



NACE RP0374 9 4 6 4 5 2 7 8 3 0500806 338 =

NACE International

Figure K2 Radii in 3.1 75-mm (0.1 25-in.) Increments

19


NACE RP0394 94 6452983 0500807 O74

RP0394-94

20

Figure K3 Radii in 3.1 75-mm (0.1 25-in.) Increments

NACE Internationai


NACE RP0394 9 4 6452983 0500808 TOO = RP0394-94

Figure K4 Radii in 3.175-mm (0.1 25-in.) Increments



~

RP0394-94

NACE RP0394 9 4 b45278L 0500807 747 W

685.8 (2

660.4 (21

22

~

Figure K5 Radii in 3.175-mm (0.1 25-in.) Increments

NACE International


NACE RP0394 9 4 6452981 0500810 669

RP0394-94

Appendix L Impact Test

Section L1: Scope mately 610 mm (24 in.) on each side and have a top facing of hardwood.

L1 .I To provide a method for assessing the coating’s resistance to damage by impact. L4.3 The impact test shall be carried out with 1 kg (2.2 Ib)

weight in a l - m (39-in.) graduated slotted tube. The ball Section L2: Equipment bearing shall be rotated every 1 O impacts to a new location and

replaced after 200 impacts. L2.1 ASTM G 14 Impact Tester, or equivalent

L4.4 Using a flat anvil for laboratory-coated specimens and L2.2 DC holiday detector the 40-mm-radius mandrel for test-ring specimens, allow the

weight to fall onto the tup such that the metal substrate is not L2.3 40-mm-radius mandrel hardened to 55 f 5 HRC deformed.

Section L3: Test Specimen L4.5 Test temperature shall be 23 k 3°C (73 k 5°F).

L3.1 Laboratory-coated specimens shall be approximately L4.6 Check each impact indentation on the test specimen for 100 mm (4 in.) square by 6 mm (0.25 in.) thick. Specimens substrate exposure with a holiday detector set at approxi- shall be prepared and coated in accordance with Paragraphs mately 1,600 V or with a wet-sponge, low-voltage holiday 5.3.2 and 5.3.3 of this recommended practice. detector.

L3.2 Test-ring specimens shall be approximately 200 mm (8 Section L5: Report in.) long x 25 mm (1 .O in.) wide x wall thickness. The 200-mm (8-in.) dimension shall be parallel to the axis of the pipe. L5.1 The following information shall be reported:

Section L4: Procedure L5.1.1 Manufacturer, product code, batch number, and date tested,

L4.1 ASTM G 14 Impact Tester shall be modified as follows: A tup (heavy metal object) shall be used that can accommo- L5.1.2 Pipe identification, if applicable, date a 15.9-mm (0.625-in.)-diameter ball bearing. The tup shall have a hardness of 50 to 55 HRC. L5.1.3 The maximum amount of energy (J or in.-lb) that

L4.2 The modified impact tester shall be screwed to a block of laminated wood. The wood block should measure approxi- L5.1.4 Holiday detection voltage.

the coating absorbed without substrate exposure, and

Appendix M Strain Polarization Test

Section Ml: Scope Section M3: Test Specimen

MI .I To determine the effects straining has on the coating M3.1 Laboratorycoated test specimens shall be 6.4 mm (0.25 in.) when cathodic protection is applied. thick.

Section M2: Equipment M3.2 Specimens shall be coated in accordance with Para- graphs 5.3.2 and 5.3.3 of this recommended practice.

M2.1 The equipment shall be in accordance with the requirements of Appendices H and K.



RP0394-94

Section M4: Procedure

M4.1 Strain the test specimen at -18°C (0°F) a minimum of 2.O0/pipe diameter, in accordance with Appendix K.

M4.2 Test the strained specimen in accordance with the requirements of Appendix H for the 28-day cathodic disbondment test, except that the plastic cylinder shall have a 25-mm ( I -in.) inside diameter (ID). The test shall commence within seven days after the specimen has been strained.

M4.3 Visually inspect the tested portion of the specimen for the presence of cracks.

Section M5: Report

M5.1 The following information shall be reported:

M5.1.1 Manufacturer, product code, batch number, and date tested,

M5.1.2 Angle of deflection in degrees per pipe diameter, and

M5.1.3 Cracking or no cracking.

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Appendix N Hot Water Soak

Section N1: Scope

N1.l To provide an accelerated assessment of the coating's adhesion to the substrate in a hot, wet environment.

Section N2: Equipment

N2.1 Hot plate or oven capable of maintaining the test temperature within * 3°C (+ 5°F) of specified value

N2.2 Plastic cylinder (such as in Appendix H)

N2.3 Utility knife

Section N3: Test Specimen

N3.1 Laboratory-coated test specimens shall be approximately 100 mm (4 in.) squarex 6 mm (0.25 in.) thick. Test-ring specimens shall be approximately 100 mm (4 in.) square x pipe wall thickness. For pipe smaller than IOO-mm (441.) diameter, the length shall be approximately 100 mm (4 in.).

N3.2 Laboratory-coated specimens shall be prepared and coated in accordance with Paragraphs 5.3.2 and 5.3.3 of this recommended practice.

Section N4: Procedure

N4.1 Glue the plastic cylinder approximately centered onto specimen.

N4.2 Pour approximately 350 mL of tap water into the plastic cylinder.

N4.3 When testing specimens cut from pipe, a heat-transfer medium (e.g., steel shot or grit) shall be employed to provide uniform heating of the specimen. Use of a metal pan partially filled with the heat-transfer medium into which thespecimen is implanted is preferred. Place on a hot plate or in an oven to

maintain the water temperature at 66 * 3°C (1 50 k 5°F) for the 24-hour test. Thethermometershall be immersed and resting on the sample.

N4.4 Evaluation Procedure

N4.4.1 After 24 hours, remove the test cell from the hot plate or oven and immediately drain the water and dismantle the test cell. While the sample is hot, use a utility knife to scribe a rectangle approximately 25 x 12 mm (1 x 0.5 in.) through the coating to the substrate. Air-cool the sample to room temperature. The evaluation shall be performed within one hour of removal from the hot plate.

N4.4.2 Within one hourafterthe removal from heat, insert a utility knife under the coating at a corner of the scribed rectangle. Use a levering action to remove the coating. Continue inserting the knife and levering under the coating until either all of the coating in the rectangle is removed or the coating demonstrates a definite resistance to the levering action.

N4.4.3 Rate the adhesion of the coating within the rectangle as follows:

N4.4.3.1 Rating 1 - Coating cannot be removed cleanly,

N4.4.3.2 Rating 2 - less than 50% of the coating can be removed,

N4.4.3.3 Rating 3 - 50% or more of the coating can be removed, but the coating demonstrates a definite resistance to the levering action,

N4.4.3.4 Rating 4 - the coating can be easily removed in strips or large chips, and

N4.4.3.5 Rating 5 - the coating can be completely removed as a single piece.



NACE RP0394 94 6452981 0500812 431

RP0394-94

Section N5: Report N5.1.2 Pipe identification, if applicable, and

N5.1 The following information shall be reported: N5.1.3 The rating obtained.

N5.1 .I Manufacturer, product code, batch number, and date tested,

Appendix O Abrasion Test Method

Section 01: Scope Section 03: Procedure Parameters

O1 .I This test procedure describes the evaluation of fusion- 03.1 Duplicate specimens (100 mm [4 in.] square x 6.3 mm bonded epoxy coatings for resistance to abrasion in the [0.25 in.] thick) coated in accordance with Paragraphs 5.3.2 laboratory. and 5.3.3 shall be tested.

01.2 This test method is similar to ASTM D 4060 (see 03.2 Operate the test for 5,000 cycles. Paragraph 3.1 .I 2 for complete reference).

Section 04: Report Section 02: Equipment

02.1 Refer to Paragraph 5 of ASTM D 4060 for required equipment. 04.1 .I Manufacturer, product code, batch number, and

02.2 CS1 7 abrasive wheel

04.1 The following information shall be reported:

date tested, and

04.1.2 Weight loss in mg per 5,000 cycles.

Appendix P Test for Interface Contamination of the Coating

Section Pl: Scope Section P4: Procedure

P1.l To determine degree of visual contamination on pipe surface.

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

Section P2: Equipment

P2.1 Microscope

P2.2 Utility knife with sharp point

Section P3: Test Specimen

P3.1 Test specimens shall be approximately 200 mm (8 in.) long x 25 (1 .O in.) wide x pipe wall thickness, with the 200-mm (&in.) dimension parallel to the axis of the pipe.

P4.1 Use the utility knife to remove an approximately 3 x 20 mm (0.125 x 0.75 in.) piece of coating from the test specimen subsequent to bending in accordance with Appendix J.

P4.2 Examine the metal interface side of the coating with the stereomicroscope at 30X to 40X magnification, and rate the percentage of interface contamination. The preferred method for determining area percentage is point counting, using an optical microscope of at least 30X to 40X magnification and a lens reticle with a point-count grid containing at least 25 points.

Section P5: Report

P51 The following information shall be reported:

P5.1 .I Manufacturer, product code, batch number, and date tested,

P5.1.2 Pipe identification, and

P5.1.3 Percentage of interface contamination.

, NACE International 25


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