Offshore Substation. Protective Coating of Steel. ETS-25 Rev. 2. technical standards. Document no , case 10/4054 ETS-25 v.

Transcription

1 technical standards Offshore Substation Protective Coating of Steel ETS-25 Rev. 2 Document no , case 10/4054 ETS-25 v. 2

2 Revision survey Document title Protective Coating of Steel Document no Target group Fabrications Contractors and Designer for Offshore substations. Document Writer Reviewer Approver Revision status Init Date Init Date Init Date 1 Approved N/A N/A AGS Approved 2 xomo POD,XOMO POD after review Minor alterations, type errors, rephrases' e.t.c. where the meaning of the text is left unchanged are not shown. Appendix no. and description Revision None Document no , case 10/4054 ETS-25 v. 2

3 Table of contents 1. Scope 1 2. References Codes and Standards 1 3. Terms, definitions and abbreviations Health, safety and environment 3 4. Technical Requirements General Classification of areas Coating systems Coating Manual Personnel Materials General Storage Thinners Abrasives Steel Materials Shop Primers Compressed air Hot-dip galvanising Surface Preparation Degreasing Steel preparation Blast cleaning Galvanised surfaces Final surface condition Application General Ambient Conditions Spray application Brush application Roller application Stripe coating Curing Carbon/stainless steel joints Painted steel joints Thermally Sprayed Metallic Coatings Passive fire protection (PFP) Repair of coating defects Unpainted Surfaces Inspection and Testing General Adhesion Holiday testing Salt testing Supervision Company Inspection 15 Document no , case 10/4054 ETS-25 v. 2

4 4.10 Reporting Topcoat Colour Scheme Warranty 16 Document no , case 10/4054 ETS-25 v. 2

5 1. Scope This technical standard specifies the requirements for the selection of corrosion protection systems, surface preparation, application procedures and inspection for protective coatings to be applied to offshore installations located in a offshore marine environment. The standard applies to structural steel, machinery and equipment like transformers located in open air as well as carbon steel piping. The standard covers the following coatings: Coating Thermally sprayed coatings Passive fire protective coatings Hot dip galvanizing It shall be emphasized that compliance with applicable parts of the codes specified in section 2.1 is mandatory. 2. References The following list of references includes relevant standards and guidelines which the present standard is based on. 2.1 Codes and Standards All regulations, codes and standards referred to in the present document shall apply in the latest revision applicable at the beginning of the tender unless noted otherwise. Document no , case 10/4054 ETS-25 v. 2 1/20

6 ISO 1461 Metallic Coatings Hot dip galvanised coating on fabricated ferrous products. NORSOK M-501 Surface preparation and protective coating ISO ISO 8503 Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness (ISO :1988/Suppl: 1994). Preparation of steel substrates before application of paints and related products - Surface roughness characteristics of blast cleaned substrates. EN1395 Thermal spraying Acceptance Inspection of Thermal Spraying Equipment. ISO Paints and varnishes Corrosion protection of steel structures by protective paint systems Part 8: Development of specification for new work and maintenance. SSPC/SSPM Volume 2 Systems and Specifications. SSPC Painting Manual, Volume 2 DNV-OS-J101 Design of offshore Wind Turbine Structures DNV-OS-J201 ISO Offshore Substations for Wind Farms Paint and varnishes - performance requirements for protective paint systems for offshore related structures 3. Terms, definitions and abbreviations DFT Dry Film Thickness MDFT Minimum Dry Film Thickness HSE Health, Safety and Environment PFP Passive Fire Protection. Coat Back continuation of passive fire protection along non fire critical steel work, from primary structural steel work, to reduce heat transfer. Stripe coat supplementary coat applied to ensure adequate protection of critical areas like edges, welds etc. Document no , case 10/4054 ETS-25 v. 2 2/20

7 Can verbal form used for statements of possibility and capability, whether material, physical or casual. May verbal form used to indicate a course of action permissible within the limits of this standard. Shall indicates requirements strictly to be followed in order to conform to this standard. Deviations from shall be followed by approved waiver. Should verbal form used to indicate that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required. 3.1 Health, safety and environment All activities shall be in compliance with safe systems of work in operation at the work location. All local statutory demands on safety of staff and on the environment, e.g. personal protection, ventilation and handling of waste, shall be adhered to during the execution of the agreed work. All blast and coating equipment shall comply with local and or regional regulations. 4. Technical Requirements 4.1 General The selection of coating systems shall take due consideration to the conditions during fabrication, installation and service life of the structure Classification of areas All external areas are to be classified in order to identify a suitable coating system to be applied. The area classifications are: Document no , case 10/4054 ETS-25 v. 2 3/20

8 Area Description Structural steel in splash zone. Structural steel below splash zone (Submerged steel) All steel above splash zone, except items given below. Passive Fire Protection. Walk ways, escape routes and lay down areas. Coating system A1 may be used on other deck areas. Coating System ref. A.7 (7A) ref./m-501/ A.7 (7B) ref./m-501/ in connection with cathodic protection. A.1 ref./m-501/ A.5 ref./m501/ A.4 Grating. A.100 /ISO 1461/ Hand-rails - kick plates. Piping T<120 C Internal walls and ceilings lined with panels, insulation or protective sheeting. A.100 /ISO 1461/A.6 A.1 ref./m-501/ A.200 Galvanized piping. A.100 /ISO 1461/ Transformer carbon steel surface located in offshore marine environment. Stainless Steel and aluminium on transformer located in offshore marine environment. A.2-2B/ ref./m-501 A.6-6A ref./m-501 The splash zone shall be defined according to recommendations given in DNV-OS- J101 unless stated otherwise in the design Coating systems The coating systems shall be selected in accordance with the specifications stated below and topcoat in colours specified in section It should be noted that of the systems A.1, A.4, A.5 and A.7 requires prequalification testing as per NORSOK M-501. Valid documentation for the execution of said pre-qualification testing shall be available. Alternative coating systems may be accepted by Energinet.dk provided that the performances of the coating systems are documented with field references and by prequalification's test certificates in accordance with ISO or NORSOK M-501. A recognized third party laboratory, to be agreed with Energinet.dk, shall carry out the technical assessment. A Manufacturer s in-house test results shall only be accepted if these have been witnessed and certified by a recognized third party, approved by Energinet.dk. The Manufacturer shall provide a track record for the coating systems with a minimum duration of three years in a relevant environment. Document no , case 10/4054 ETS-25 v. 2 4/20

9 The paint contractor may at his sole discretion, propose an alternative paint system for system A.200, further the paint contractor may substitute galvanisation with metal spaying for handrails in accordance with NORSOK M-501 system A.2 The systems shall be approved by Energinet.dk. Document no , case 10/4054 ETS-25 v. 2 5/20

10 System no. Coating System MDFT µm A.1. 1 coat zinc rich epoxy (zinc contend min 80% by mass) High Solid Epoxy Polyurethane top coat Total A.4 Epoxy Deck Coating Flint reinforced, non-skid surface A.6 1 coat epoxy sealer (after manufacturers recommendations High solid epoxy: 150 A.7-7A A.7-7B Polyurethane topcoat Total: 225 Two component epoxy. Minimum number of coats: 2 DFT of complete coating system: 600 Two component epoxy. Minimum number of coats: 2 DFT of complete coating system: 350 A.200 Waterborne acrylic (zinc phosphate pigmented) Waterborne acrylic (zinc phosphate pigmented) Waterborne acrylic enamel (application temperature>10 C) Total A.100 Hot dip galvanised Additional painting is required for handrails and kick-plates, system no. A.6 shall be used. Pre-treatment and sealer after paint manufacturers recommendations A.5 1 coat epoxy primer(as per paint manufacturers requirements) A.2-2B Intumescent Epoxy. Polyurethane Top coat Thermally sprayed zinc or alloys of zinc: Tie coat: Intermediate coat: Topcoat: 80µm 80µm 80µm 240µm Document no , case 10/4054 ETS-25 v. 2 6/20

11 4.1.3 Coating Manual A detailed coating manual based on the requirements of this standard shall be established. The manual shall as a minimum contain the following: Identification of equipment for surface preparation and application. Procedures/Instructions. Information given on coating system data sheets. Safety data sheets for each product. Product data sheets. The coating procedure shall be qualified by coating procedure tests as described in NORSOK M-501, section (Systems A.1, A.4, A.5 and A.7) Deviations from the coating procedure are only allowed upon re-approval by product manufacturer and Energinet.dk Personnel Only professional skilled blasters, painters, metal spray operators and passive fire protection operators shall be used. Blasters and painters working on every painting job should be qualified in accordance with the qualifications requirements stated in NORSOK M-501. Passive fire protection operators shall be authorised by manufacturer of the product. A skilled foreman shall supervise the blasters and painters. Personnel carrying out inspection and or QC shall be qualified in accordance with FROSIO LEVEL III or NACE level III. 4.2 Materials General The coating materials shall be suitable for the intended use and shall be selected after evaluation of corrosion protective properties, health and safety, application conditions and documented experience with the coating material and system Storage The coating materials shall be protected against ignition sources and shall remain within storage temperatures and conditions specified by manufacturer. The Contractors quality assureds system shall ensure full traceability of production. The coating materials and solvents shall be stored in the original container bearing the manufacturers label and instructions. Materials shall be used within its shelf life. Document no , case 10/4054 ETS-25 v. 2 7/20

12 4.2.3 Thinners Thinners shall be specified by the paint manufacturer. The mixing and thinning directions given by the paint manufacturer shall be followed Abrasives The abrasives for blasting shall be grit. The size of the blasting materials shall be suitable for the required surface profile (anchor pattern profile). Blasting abrasive shall be dry, clean and free from contaminants. The abrasive agent shall on a continuous basis be checked for salts in accordance with ISO Each batch of abrasive shall be tested to check that the abrasive meets the requirements as specified in the relevant ISO standard. On carbon steel surfaces metallic abrasives may be used On stainless steel, duplex and super duplex surfaces only non-metallic abrasives shall be used Steel Materials The steel shall be inspected and released before abrasive blasting is commenced. The surface shall be checked for damages, sharp edges, weld defects (e.g. pores and splatter), laminations, oil, grease and coupling medium from ultrasonic examination of welds etc. Steel subject to surface preparation on site shall as a minimum requirement be in accordance with rust grade B according to ISO Shop Primers Shop primers shall be removed prior to application of the coating system; hence it shall only be regarded as temporary corrosion protection unless approved by coating supplier and compatible with applicable coating system Compressed air The compressed air shall be free of water and oil. Adequate separators and traps shall be provided. The presence of oil and water shall be determined in accordance with ASTM D 4285 following every compressor start-up and by start of each shift Hot-dip galvanising Hot-dip galvanising is the preferred method for the protection of pre-fabricated structural steelwork such as gratings, ladders, stair-treads, handrails etc. However, for locations close to the sea, offshore locations and locations where painting is required for safety or environmental reasons, galvanised components such as ladders and hand railings shall be protected with a paint system as specified in this ETS applied on top of the galvanised layer. Painting of galvanised grating is not required. Galvanising of supports, piping, hand railings, gratings and other items as specified in the contract drawings shall be carried out in accordance with ISO Hot dip galvanizing may be substituted by thermal sprayed coating system. Document no , case 10/4054 ETS-25 v. 2 8/20

13 4.3 Surface Preparation Degreasing Any oil and grease contamination shall be removed in accordance with SSPC/SSPM Volume 2, grade SP Steel preparation Before the blast cleaning can commence all sharp edges, fillets, corners and welds shall be rounded or smoothened by grinding to a minimum edge radius of 2 mm. (Ref ISO annex D5) Any major surface defects, particularly surface laminations or scabs harmful to the protective coating system shall be removed by suitable dressing. All welds shall be inspected and, if necessary, repaired prior to final blast cleaning Blast cleaning All steel to be dry blasted to min. Sa 2½ according to ISO and the anchor profile of the surface shall be graded according to min ISO 8503 grade Medium G (50μm - 85μm), unless the coating suppliers requirements calls for a stricter request. The anchor pattern shall have a sharp profile. Steel that are subject for galvanisation shall also be cleaned and blasted as noted. The abrasive blasting shall take place under controlled environmental conditions, i.e. at indoor environment or similar by the use of temporary structures. Inhibitive washing to prevent rusting after blast cleaning shall not be used Galvanised surfaces Where painting of galvanised surfaces is required by design, the surface shall prior to painting have been sweep blasted to ensure adhesion of the paint. Small areas of galvanised coating damaged by cutting, welding, drilling or any preparation during fabrication, erection, transportation or installation, shall be repaired as described in ISO Final surface condition Final visual inspection of welds and surface shall take place after sandblasting. Any defects, pinholes etc. shall be repaired; weld and grinding spatter shall be removed. Repaired areas shall be re-blasted. Energinet.dk shall witness this inspection. After blasting and prior to painting, the painting area shall be cleaned for blasting grit and dust. Particle size and particle quantity shall not exceed rating 2 of ISO Document no , case 10/4054 ETS-25 v. 2 9/20

14 4.4 Application General The coating Manufacturer s product data sheets and specifications for mixing, application and curing shall be considered an integral part of this ETS. The Coating Contractor shall be responsible for obtaining the latest revision of Product and Safety Data Sheets of each product from the Manufacturer. All coating systems shall be applied in accordance with this ETS and the coating manufacturer's instructions and data sheets. Any conflicting requirements shall be brought to the attention of Energinet.dk Ambient Conditions Final blast cleaning or coating application shall not be made if the relative humidity % RH is > 85% and when the steel temperature is less than 3 C above the dew point. Coating shall only be applied at ambient and steel temperatures in accordance to relevant data sheets Spray application The method of application shall be airless spray and it shall further be in accordance with the coating manufacturer s recommendation for the particular coating being applied. The coats shall be applied uniformly and skips, runs, sags and drips shall be avoided. Furthermore the coats shall be free from blisters, pinholes and holidays. The coats shall be applied in multiple layers and shall overlap for each pass of the gun. Contrasting colours shall be used for each coat of paint so that the stage of painting may be ascertained by the colour. Contamination of painted surfaces between coats shall be avoided. Any contamination shall be removed. Any damage to the previous coat shall be repaired before application of further coat Brush application Provided that the coating Manufacturer confirms that the coating material is suitable for brush application, it may be used for spot repair, stripe coating or on other irregular surfaces and small bore parts not suitable for spray application. When paints are applied by brush, the brush shall be of a style and quality acceptable to the coating manufacturer Roller application Roller application shall only be allowed for small repair of topside coating. Rollers shall be of good quality to ensure uniformity of the applied coating. Document no , case 10/4054 ETS-25 v. 2 10/20

15 Rollers may be accepted for application of PFP if recommended by manufacturer Stripe coating Before each coat, a stripe coat shall be applied by brush to all welds, corners, behind angles, edges of beams, etc. and areas not accessible by spray in order to obtain the specified coverage and thickness Curing Each layer of coat shall cure for the time specified by the paint manufacturer and the specified minimum recoat interval of the individual paint shall be kept. The maximum time interval between applications of coats must not be exceeded. If the maximum interval is passed, the surface must be cleaned according to manufacturer's recommendations, including careful abrasive sweep-blasting with mineral abrasives, followed by de-dusting Carbon/stainless steel joints If stainless steel is connected to carbon steel, the stainless steel part shall be coated 50 mm beyond the contact zone onto the stainless steel. However the dry film thickness requirement for the connected carbon steel part shall be applicable. Abrasive blasting shall be made with non-metallic grit. The coating shall not contain zinc Painted steel joints Bolted painted steel joints shall be identified during the design phase. Sealant or greasing with suitable Chesterton 740, heavy duty rustguard or equal shall be used. 4.5 Thermally Sprayed Metallic Coatings The materials and conditions for metal spraying shall be in accordance with ISO The coating material shall be Al 99.5 of DIN or equivalent. Other materials are subject for the approval of Energinet.dk. The equipment for the application should follow the guidelines stated in EN The coating shall be firmly adhered. The surface after spraying shall be uniform and free of lumps, loosely adherent spattered metal, bubbles, ash formation, defects and uncoated spots. The paint contractor's quality system shall ensure full traceability of the production. All coating materials shall be supplied with product data sheets and quality control certificates, and be marked with manufacturer s name, manufacturing standard, metal composition, weight and date of manufacture. Document no , case 10/4054 ETS-25 v. 2 11/20

16 4.6 Passive fire protection (PFP) The use and application of sprayed on passive fire protection is not covered in detail by this standard. Where the design stipulates fire protection the following should however be highlighted: Coating system no. 5A according to NORSOK M-501 shall be applied under the sprayed passive fire protection, if approved by the manufacturer of the passive fire protection coating. Passive fire protection system shall be of epoxy type. The system is to be approved by Energinet.dk. Pinning shall be completed before abrasive blasting and priming. The coating work (passive fire protection coating) is to be carried out in accordance with the requirements given in NORSOK M-501, section 9 and manufacturer's specification. The passive fire protective material shall follow applicable requirements to the fire protective properties (heat input, duration, etc.). A top coat in accordance with the manufacturer recommendation shall be applied. Operators including pump machine operators shall be qualified, trained and certified according to manufactures certification scheme. Coat back shall generally be 450mm unless otherwise stated. 4.7 Repair of coating defects All repair work shall be executed in accordance to the paint contractor's paint repair procedure. Damaged areas, defects in the coating system such as over-runs, drips and smears that have to be removed or areas with inadequate dry film coating thickness shall be re-cleaned. The re-cleaning shall carry over on to the secure surrounding coating for not less than 250 mm all round and the edges shall be feathered (over a width of at least 70 mm). After the surface cleaning the specified coating system or the required layers of the specified coating shall be re-applied. Any additional coats shall blend in with the final coating on adjoining areas. Paint Manufacturers shall be consulted if the existing coating requires abrading before over-coating to obtain good bonding. Surface preparation with wire brush (manual or mechanical) is not accepted. Document no , case 10/4054 ETS-25 v. 2 12/20

17 All requirements to metal spraying shall apply in accordance with paint manufacturers repair procedure. 4.8 Unpainted Surfaces The following items shall not be coated unless otherwise specified: aluminium, titanium, un-insulated stainless steel, insulated stainless steel heating/ventilation/ air-conditioning ducts, chrome plated, nickel plated, copper, brass, lead, plastic or similar; 4.9 Inspection and Testing General Inspection shall be carried out in accordance with below table: Test type Method Frequency Acceptance criteria Consequence Environmental conditions Ambient and steel temperature. Relative humidity. Dew point Before start of each shift + minimum twice per shift In accordance with specified requirements No blasting or coating Visual examination Visual for sharp edges weld spatter slivers, rust grade, etc ISO % of all surfaces No defects, see specified requirements Defects to be repaired Cleanliness a) ISO b) ISO a) 100% visual of all surfaces b) Spot checks a) In accordance with specified requirements b) Maximum quantity a) Re-blasting b) Re-cleaning and re-testing until acceptable. and size rating 2 Salt test ISO and Spot checks Maximum conductivity Repeated washing with potable water ISO corresponding to 20 mg/m 2 NaCl and re-testing until acceptable. Roughness Comparator, stylus instrument or testex tape (ISO 8503) Each component or once per 100 m 2 As specified Re-blasting Curing test (for Zn silicate) ASTM D4752 Each component or once per 100 m 2 Rating 4 to 5 Allow to cure Document no , case 10/4054 ETS-25 v. 2 13/20

18 Test type Method Frequency Acceptance criteria Consequence Visual examination of Visual to determine curing, 100% of surface after each coat According to specified requirements Repair of defects. coating contamination, solvent retention pinholes/popping, sagging and surface defects Holiday detection ISO Voltage, see table 1. As per coating system data sheet. No holidays Repair and retesting. Dry film thickness ISO Calibration on a smooth surface ISO ISO 19840, and coating system data sheet as per NORSOK Repair, additional coats or recoating as appropriate 501. Adhesion ISO 4624, using equipment with an automatic centred pulling force, and carried out when coating system are fully cured Spot checks See below Coating to be rejected Adhesion Adhesion testing shall be carried out on the component. The need and number of spot checks for adhesion to be performed on the component shall be defined and agreed with Energinet.dk prior start of the surface treatment. Testing shall be done on fully cured systems only, i.e. not less than 14 days after the application of the final layer. Spots damaged by the adhesion tests shall be repaired in accordance with the contractors repair procedure. For sprayed on passive fire protection, maximum 50% reduction from CPT value read as cohesion is acceptable. Absolute minimum values are 2.0 Mpa for epoxy based products. Epoxy based passive fire protection may be used to glue the test dollies to the primer in order to measure the adhesive strength. For the coating systems A.1, A.6 and A.7, 50% reduction of average adhesion value from Coating Procedure Test (CPT) is acceptable as minimum adhesion during production coating. Absolute minimum value is 5 Mpa. For adhesion test during CPT, glue failure with values below 15 Mpa is not accepted. X-cut test (ASTM D3359) can be used as a supplementary test for adhesion, where relevant. Document no , case 10/4054 ETS-25 v. 2 14/20

19 4.9.3 Holiday testing Holiday detection shall only be executed for submerged paint systems (A.7 7B). The continuity of the coating shall be 100% holiday inspected in accordance with ISO tables Salt testing Test for water-soluble salts shall be performed after washing by high pressure water hosing or similar method and before abrasive blasting. The test shall be performed in accordance with ISO (the Bresle method) and assessment shall be performed in accordance with ISO Accept criterion is a conductivity corresponding to a NaCl content of max 50 mg/m 2 Additional tests shall be performed in case of changes in condition which may affect the contents of salt on the surface, e.g. sea and road transport or storage near the sea Supervision The Coating Contractor shall arrange for a Coating Supervisor from the selected coating supplier to be in attendance at the paint shop, to advice on the application of paint system. The supervisor shall be certified by NACE or FROSIO level III Supervision shall follow the requirements stipulated in ISO Company Inspection Energinet.dk is to be given due notice regarding the coating work to allow for their inspection Reporting A log is to be maintained at a daily basis which as minimum contains the below stated information: Identification of person who has carried out the work Identification of areas to be coated Surface temperature at work start and stop Air temperature, relative humidity and dew point Time lapse between coats Dry Film Thickness DFT The above information shall be included for all workers and each step of the painting process. Document no , case 10/4054 ETS-25 v. 2 15/20

20 The forms recommended in ISO or similar shall be used Topcoat Colour Scheme The colour scheme of the relevant structures shall be agreed with Energinet.dk. Below are recommended colours and RAL identification numbers listed. Colour RAL-1K designation Area/Item Grey RAL 7038 Topside steel incl. Cladding, skids, stair towers and walkways Grey RAL 7038 Carbon steel vessels, tanks, piping and equipment. Yellow RAL 1004 Cranes and crane pedestals Crane beams and pad eyes Green* RAL 6024 Helideck surface Ref. Civil Aviation Administration, BL 3-5. Green RAL 6024 Plated lay down areas Yellow RAL 1004 Jacket structure Red RAL 3001 Transition piece incl. Support beams and flanges Red RAL 3020 Fire fighting equipment Red RAL 3026 Sea escape ladders * If the helideck is of aluminium type it shall not be coated. Only required markings shall be applied. 5. Warranty Contractors undertaking painting and/or coating work which is to be carried out in accordance with this ETS shall guarantee the quality of their coating work. Before any painting or coating work shall commence, the warranty period and associated coating condition shall be agreed with Energineet.dk. A warranty period of five (5) years, at the coating condition specified, is required for coating systems. Document no , case 10/4054 ETS-25 v. 2 16/20