Specification for Fusion Bond Epoxy Coating

Transcription

1 Specification for Fusion Bond Epoxy Coating Specification for Fusion Bond Epoxy Coating 1 of 8

2 TABLE OF CONTENTS 1.0 SCOPE REFERENCE DOCUMENTS MATERIALS EQUIPMENT AND LABOR SURFACE PREPARATION COATING APPLICATION INSPECTION AND TESTING REPAIRS STORAGE, HANDLING AND SHIPPING PERFORMANCE OF WORK...6 Specification for Fusion Bond Epoxy Coating 2 of 8

3 1.0 SCOPE 1.1 This specification shall govern the materials, application, inspection, repairs, handling of bare and coated pipe, and other requirements for external coating of pipe using fusion bonded epoxy. The work includes the furnishing of all labor, materials, tools and equipment and the performance of all operations and incidentals necessary for the coating, handling, storing and shipping of coated pipe. Furthermore, the work shall meet any additional requirements stated elsewhere in the CONTRACT. As used in this specification, the following definitions shall apply: COMPANY: CONTRACTOR: CONTRACT: The firm responsible by contract for the application of the fusion bonded epoxy to the pipe Signed work agreement between COMPANY and CONTRACTOR. CONTRACTOR shall obtain COMPANY's written approval for any deviations from the requirements of this specification or specifications, standards and drawings referenced herein or elsewhere in the CONTRACT. In case of conflict between documents, the order of precedence given in the CONTRACT shall govern. This document is not intended to be all inclusive, and the use of the requirements set forth does not relieve the CONTRACTOR of his responsibility to supply a product capable of performing its intended service. 2.0 REFERENCE DOCUMENTS The coating shall be applied in accordance with the latest editions and addenda of the following codes and standards. 2.1 Codes and Standards Steel Structures Painting Council SSPC SP 1 Solvent Cleaning SSPC SP 5 White Metal Blast Cleaning NACE TM Visual Standard for Surfaces of New Steel Centerfugally Blast Cleaned with Steel Grit and Shot. National Association of Corrosion Engineers RP Recommended Practice, High Voltage Electrical Inspection of Pipeline Coatings Prior to Installation. 2.2 Project Specifications Pipe Handling: Pipe Storage and Onshore/Offshore Transportation Line Pipe Specification 2.3 COMPANY General Specifications Field Application of Fusion Bonded Epoxy 3.0 MATERIALS The CONTRACTOR shall supply all coating materials required by this specification. 3.1 Pipe Unless otherwise specified, all pipe will be furnished free of mill coating. 3.2 Powder Corrosion coating shall be a thermosetting fusionbonded epoxy powder, such as Interpon HD3005, Lilly 1500, Scotchkote 206N or Napguard 2501 or COMPANY approved equal. The coating materials shall be handled, stored and applied in accordance with the manufacturer's specifications, or as Specification for Fusion Bond Epoxy Coating 3 of 8

4 directed by an authorized representative of the coating manufacturer. Each material container shall be marked with a durable marking material to display the date of manufacturer, manufacturer's material name, number and batch number. Each batch of material shall be certified in writing, including the results of property tests that were conducted for quality assurance before packaging. 3.3 Patching Compound Patching compound, such as Interpon HD 3010, a product compatible with Lilly 1500, Scotchkote 206N or Napguard 2501 or COMPANY approved equal, shall be used on all repairs to the fusion bonded epoxy coating. Patching compound shall be compatible with and adhere to the primary corrosion coat, and shall be supplied and approved by the coating manufacturer. 3.4 Abrasive Material for abrasive cleaning shall be a steel grit and/or shot particle of a size that will produce an angular profile of not less than 1.5 mils nor more than 2.5 mils in depth. Worn abrasive shall be replaced with new material. The abrasive material and compressed air for blasting shall be free of impurities, water and oil. Adequate separators, dryers and traps shall be provided and kept empty of condensate. 4.0 EQUIPMENT AND LABOR 4.1 Condition of Equipment All equipment and tools furnished by the coating CONTRACTOR shall be of good quality, maintained in good operating condition and suitable for use to apply materials required by this specification. All equipment shall be subject to approval by the COMPANY. Equipment shall be capable of coating joint lengths up to 42 feet long. 4.2 Rubber Wheels All cleaning and coating machines (and pipe moving wheels or rollers) shall be equipped with rubber wheels or wheels overlayed with hard fiber to prevent marking or indenting of the pipe. Knurled steel or other type wheels, capable of marking or indenting the pipe or coating shall be prohibited. Steel wheels may be used in the furnace area as a result of the temperatures involved and additionally to ground the pipe for the electrostatic application of the fusion bonded epoxy provided that damage beyond that allowed in the specification does not occur. Any damage beyond the specification limits shall be repaired at the CONTRACTOR's expense. 4.3 Holiday Detector The electrical equipment used to test the coating shall be portable, low amperage, adjustable voltage, pulse type holiday detector employing an audible signaling device. The holiday detector shall be furnished with a coil spring electrode or a suitable brush type electrode. An in line conductive rubber electrode may be used to test for holidays and when used, all holidays shall be automatically marked when detected. 4.4 Labor The CONTRACTOR shall provide supervision and labor for the entire coating operation from the time of receiving the pipe to loading out of transportation. The CONTRACTOR shall provide necessary facilities for COMPANY supervision and inspection of all the work. 5.0 SURFACE PREPARATION 5.1 Preparation for Blasting Prior to blast cleaning, external surfaces shall be inspected and pre cleaned according to SSPC SP 1, to remove oil, grease and loosely adhering deposits. Visible oil and grease spots shall be removed by solvent wiping. Only COMPANY approved safety solvents which do not leave a residue shall be used. Prior to final grit blast, the pipe shall be preheated to a temperature from 120F to 150F in order to assure Specification for Fusion Bond Epoxy Coating 2 of 8

5 a dry surface and to prevent oxidation of the cleaned surface. The heat source shall not leave a residue to contaminate the pipe surface. Ends of pipe shall be protected by plugs in such a manner as to prevent entry of abrasive into the pipe interior during blasting. Any abrasive entering pipe shall be removed prior to coating. 5.2 Blasting The pipe surface to be coated shall be cleaned to a "White Metal" finish, or equivalent, in accordance with SSPC SP 5. The blast pattern shall be a uniform, angular anchor profile with a minimum depth of not less than 1.5 mils to a maximum of 4.0 mils. For consistent surface finish, a stabilized working mix of the cleaning media shall be maintained by frequent small additions of a new grit commensurate with consumption; infrequent large additions shall be avoided. The cleaning media working mix shall be maintained clean of contaminants by continuous effective operation of blasting machine scalping and air wash separators. 5.3 After Blasting After blast cleaning, the pipe surface to be coated shall be examined. All surface imperfections, such as slivers, scabs, burrs, weld splatter or gouges shall be removed by grinding. Grinding is only allowed in so far as it will not reduce the wall thickness of the pipe beyond the minimum given by Project Specification / Pipe that cannot be repaired or that is dented shall not be coated. All ground areas shall be reblasted to the above requirements. After blasting, the inside and outside of the pipe shall be left clean and free of abrasive materials, dust or other blasting residue. A brush off air blast or vacuum type cleaner shall be used to clean the entire pipe. A 10 percent solution of Oakite 33 or COMPANY approved equal shall be applied to the surface while surface is 110 F to 150 F. Rate of application to be 1 gallon of solution per 100 square feet of surface area. Dwell time to be minimum of 20 seconds. Spray at 600 to 800 psi pressure fresh water to remove acid residue. Minimum of 2 1/2 gallons of water per 100 square feet of surface is required. Remove excess water by squeegee or air knife. The cleaned pipe surfaces shall be protected from conditions of high humidity, rainfall, or surface moisture. The cleaned pipe surface shall be coated the same day it is cleaned, and shall not be allowed to flash rust before coating. Total elapsed time between grit blasting and coating of the blast cleaned surface shall be kept to a minimum to avoid the formation of oxides on the surface. 6.0 COATING APPLICATION 6.1 Heating The pipe shall be heated to a temperature within the tolerances recommended by the manufacturer of the coating material to be applied. However, the pipe shall not be heated to a temperature in excess of 500 F at any time during the heating process. Oxidation of the steel, prior to coating, in the form of "blueing" or other apparent oxide formation is not acceptable. Visual formation of such oxides shall cause the pipe to be re blasted prior to coating. Any pipe which is heated in excess of 525 F shall not be coated, but shall be set aside and handled in accordance with COMPANY's instructions. 6.2 Temperature Check The pipe shall be continuously checked for the proper temperature prior to coating by the use of an accurately calibrated optical pyrometer. The calibration of the pyrometer shall be at least twice daily. Graduated "Tempilstick" crayons may be used in continuous operation as an alternate method to measure the pipe temperature providing areas of testing of pipe temperature, with the "temp stick", do not exceed 1/8" wide by 1/2" long. Minimum and maximum preheat temperatures shall be strictly maintained in accordance with the coating manufacturer's printed instructions. Allowances for Specification for Fusion Bond Epoxy Coating 3 of 8

6 heat loss due to both radiation and convection shall be made during heating operation. Caloric intake required to melt the powder shall also be considered as pipe temperature will be affected by this heat loss. 6.3 Coating Thickness The nominal dry film thickness shall be 18 mils. The minimum dry film thickness shall not be less than 16 mils nor greater than 24 mils dry film thickness. Any joint having less than or more than the specified thickness will be completely reblasted to its original specified cleaned surface before re coating. The coating shall have a cut back at each end of the pipe a maximum of 2.5" and a minimum of 1" or as recommended by the coating manufacturer. 6.4 Recycled Powder The use of recycled powder shall be permitted if proper recovery and screening equipment is used and maintained. This equipment must meet the approval of the COMPANY and the coating manufacturer. The recycle system shall automatically and continuously blend recycled powder with virgin powder in the delivery system. All air used to fluidize, transport and apply the powder shall be dry and free of oil and any contamination. 6.5 Curing After application of the powdered coating, the coating shall be allowed to cure the recommended time and at the recommended temperature before any forced cooling shall be used. The coating manufacturer shall recommend the proper timing and temperature requirements. During the period of coating and curing, the pipe shall be handled so as to avoid damage to the coating. After the coating has cured it shall be cooled with air or water spray to a temperature the coating manufacturer recommended for inspection and repair. 7.0 INSPECTION AND TESTING 7.1 COMPANY Access for Inspection COMPANY representative(s) shall be given ready access to inspect the CONTRACTOR's quality control procedures, methods and results of the coating materials, equipment, and the CONTRACTOR's work. All stages of the work shall be subject to full time inspection by the COMPANY. Such inspection shall not relieve the CONTRACTOR of his responsibility to provide materials and workmanship to this specification. 7.2 Inspection of COMPANY Supplied Pipe Upon receipt of line pipe or pipe bend material supplied by COMPANY, CONTRACTOR shall perform a thorough inspection. Any damage to the material such as dents, gouges, buckles, ovalization or damage to the weld bevels shall be recorded against the pipe mill number and reported to the COMPANY. COMPANY may request CONTRACTOR to make repairs at COMPANY's expense or instruct CONTRACTOR to set aside and not coat pipe pending COMPANY's further instructions. Any damage discovered during subsequent stages of the coating or inspection operations shall be made good by CONTRACTOR at his expense. 7.3 Joint Identification For each joint of pipe, the following measurements, information and pipe identification shall be recorded before coating operations commence. a. Pipe mill number b. Joint length c. Weight (bare pipe) d. Any other information stencilled on the outside or inside of the pipe. If the pipe mill number is not stencilled on the inside of the pipe it shall be paint stencilled there before coating. Pipe joint identification shall be preserved by the CONTRACTOR at all times. 7.4 Blasting Cleaning Specification for Fusion Bond Epoxy Coating 4 of 8

7 Inspection of the blasted surface shall be by comparison to the white metal blast cleaning standards in NACE TM Visual and Holiday Inspection After coating operations have been completed, the CONTRACTOR shall conduct electrical inspection of all exterior coating of the pipe with an electronic holiday detector. The cured coating shall be of uniform color, gloss and thickness and shall be free of any irregularities such as blisters, pinholes, "fisheyes", sags and dirt inclusions. Any defect in the coating shall be satisfactorily repaired at the expense of the CONTRACTOR. The test voltage shall be in accordance with NACE RP Because of variables, such as relative humidity and temperature, the detector voltage shall be adjusted no less than twice daily: once just before starting work in the morning and once just before starting work in the afternoon. To ensure proper inspection voltage, the equipment shall be grounded in accordance with the instructions of the equipment manufacturer. All electrically detected holidays, discontinuities or coating defects rejected by the COMPANY's representative shall be repaired and reinspected electronically to determine that coating has been repaired to meet specifications. In addition to the above holiday inspection, at least one joint of pipe per working shift shall be inspected for an acceptable degree of foaming. Excessive foaming shall not be evident when viewing the coating under a 10 power microscope. Coating shall fall within the 1 5 grade range as shown in section 6.2 of COMPANY's General Specification GS GC, Field Application of Fusion Bonded Epoxy. 7.6 Thickness Each individual joint shall receive at least two film thickness measurements. Film thickness shall be measured by use of a "Mikrotest" film thickness gauge, range 0 40 mils or COMPANY approved equal. Calibration of the gauge shall be verified daily according to National Bureau of Standards Certified Coating Thickness Calibration Standards. 7.7 Adhesion Adhesion of the cured coating to the pipe surface shall be checked on a random basis by pushing a sharp knife blade through the coating to the surface of the pipe, in a whittling motion, to attempt to remove the coating. The coating shall not strip or peel from the steel. Repairs shall be made after the adhesion test has been completed. 8.0 REPAIRS 8.1 Rejection Any coated joint of pipe having an average of more than one holiday per 15 sq. ft. of surface area shall be considered as having major coating defects. Pipe with major coating defects such as partially coated joints, unbonded coating, inadequate or excess film thickness, excessive foaming, or more than one holiday per 15 sq. ft. of surface area shall be returned to the pipe supply rack to be re cleaned and re coated in the same manner as specified for bare pipe. Pipe surface damage caused by CONTRACTOR's handling and operation which causes specified holiday count to be exceeded is a cause for rejection and repair at CONTRACTOR's expense. CONTRACTOR shall provide a minimum of two grinders for a normal plant production level of 300 joints per 10 hour shift at the cleaning unit to prepare the pipe surface for acceptable levels of tolerance. CONTRACTOR shall provide additional grinders when normal production levels are exceeded. If poor pipe surface as supplied by COMPANY is encountered which causes excessive holiday count, the COMPANY shall have the option of reducing the holiday count at COMPANY's expense by one of two methods: 1. By additional grinding/buffing. 2. By application of additional FBE mileage. Specification for Fusion Bond Epoxy Coating 5 of 8

8 8.2 Repair of Coating All coating defects disclosed by the holiday detector and obvious defects that may occur as the result of mechanical damage, steel slivers, or any other causes, shall be marked by chalk or crayon and repaired in the following manner by the CONTRACTOR. Prior to repairs, the area surrounding the defect shall be abraded utilizing 80 grit carborundum cloth. Any slivers detected shall be removed by light grinding with media that will maintain the anchor profile. All repairs shall be made using patching compound. Touch up sticks shall not be used. When using patching compound, equal parts of Component A and Component B shall be mixed to a uniform color and applied to the abraded surface with suitable spatula at a recommended minimum film thickness of 18 mils. Patched areas necessitated by mechanical damage shall overlap the surrounding undamaged coating by a minimum of 0.5 in. jobsite by truck, rail or barge, as specified in the CONTRACT. Pipe shall be shipped in such a manner as to adequately protect the pipe and its coating. Pipe shall be loaded for shipping in compliance with existing shipping standards and regulations PERFORMANCE OF WORK CONTRACTOR shall guarantee that work performed on external coating of pipe shall be in accordance with this specification and that the application of the coating system shall be in accordance with the specifications of the coating material manufacturer. The COMPANY's representative shall have proper access rights to CONTRACTOR's plant and property to assure the COMPANY that the foregoing specifications are being followed. All repairs shall be re inspected both visually and electrically and shall be acceptable to the COMPANY. 9.0 STORAGE, HANDLING AND SHIPPING Pipe shall be handled and stored in a manner to prevent damage to pipe walls, beveled ends, and coating. Pipe shall be handled, transported and stored in accordance with Specification No CONST SPL/OSPL All pipe handling shall be with equipment approved by the COMPANY's representative. Pipe or coating damaged by the CONTRACTOR in handling or other operations shall be satisfactorily repaired at no expense to the COMPANY. The coated pipe shall be stacked in such a manner that the exterior coating does not contact a hard surface which will cause coating damage. Stacking height shall be reduced at COMPANY representative's request if he observes detrimental effects to the pipe or coating due to stacking. Pipe will be transported from the coating yard to the Specification for Fusion Bond Epoxy Coating 6 of 8