1. GENERAL

This specification defines minimum quality and technical standards governing materials procurement, application, testing and inspection of offshore pipeline field joint coatings. This specification is to be used in conjunction with the following documents:

· Basis of Design 84506-60-00-2L-060

· General Specification 84506-60-00-2L-000 - Definitions and Specification Directory

· General Specification 84506-60-00-2L-010 - Quality Assurance / Quality Control

· General Specification 84506-60-00-2L-020 - General Offshore Specification

· DnV OS-F101 Submarine Pipeline Systems 2000

· NACE RP-02-74 High Voltage Electrical Inspection of Pipeline Coating Prior to Installation

· SSPC-SP-1 - Specification for Solvent Cleaning

· SSPC-SP-3 - Specification for Power Tool Cleaning

2. FIELD JOINT COATING REQUIREMENTS

During installation of the pipelines, the field joint coating station on the laybarge shall be at such level as to avoid direct wave splash and seaspray. CONTRACTOR shall use heat-shrink sleeves for anti-corrosion coating and composite urethane for infill material.

3. PROCEDURES

CONTRACTOR shall submit to COMPANY for approval field joint coating application procedures. Procedures shall incorporate actual equipment, materials, surface preparation, coating application, infill application, repairs and time required to complete each application using the procedure submitted. COMPANY may request and witness a demonstration test performed prior to mobilization.

3.1 Application procedures shall reflect material manufacturer recommendations. Material Technical Datasheets shall be submitted to COMPANY for each material to assist COMPANY approval of that material.

4. STEEL PREPARATION

Following COMPANY acceptance of field weld NDT, bare pipe at the field joints shall be thoroughly cleaned to gray metal per SSPC-SP-3, using mechanical brushes.

4.1 CONTRACTOR shall remove any adjacent coating sections not firmly bonded to the pipe. Pipe surfaces shall be free of oil, grease, moisture, dirt, rust, slivers, burrs, weld spatter, and other material that may impair proper bonding. Oil and grease shall be removed using a COMPANY-approved emulsifying detergent or solvent in accordance with SSPC-SP-1.

4.2 VENDOR-applied anti-corrosion coating shall be cleaned with a powered brush per SSPC-SP-3 for at least 50 mm from the exposed steel and feathered to the pipe surface. After cleaning and feathering, CONTRACTOR shall remove dust from the cleaned surface with a soft brush.

4.3 All prepared surfaces shall be 100% visually inspected by CONTRACTOR for surface irregularities, such as excessive contours in the weld bead or weld spatter which would impair the application or performance of the finished coating. Such defects, if found, will be brought to the attention of COMPANY and suitable remedial action shall be proposed by CONTRACTOR for approval by COMPANY.

4.4 Oxidation, tarnishing or contamination of the cleaned surface is not permitted and all girth weld areas must meet SSPC-SP-3 standard immediately prior to coating installation. Any girth weld area that shows signs of oxidation or any girth weld area that remains uncoated after thirty minutes from preparation shall be re-prepared to the original specification.

5. HEAT-SHRINK SLEEVE APPLICATION

5.1 CONTRACTOR shall use Raychem WPC shrink sleeves for infield lines and WPCT-60 shrink sleeves for export lines or COMPANY-approved equal as anti-corrosion field joints. Sleeves used shall have thermochromatic indicators to demonstrate correct and even heating of the sleeve.

5.2 Sleeves shall be stored in accordance with sleeve manufacturer’s instructions.

5.3 CONTRACTOR shall apply pre-heat uniformly to the field joint and complete the joint coating in strict accordance with the manufacturer’s recommendations. Heat-shrink sleeves shall be wrapped around the field joint, centered on the weld, and shall overlap vendor-applied anti-corrosion coating by 50 mm and onto itself at the 12 o’clock position by a minimum of 50 mm after completion of the joint. A sleeve closure shall be applied in accordance with manufacturer’s instructions.

6. FIELD JOINT ANTI-CORROSION COATING INSPECTION

6.1 CONTRACTOR shall fully inspect each field joint anti-corrosion coating prior to joint infill.

6.2 CONTRACTOR shall furnish a COMPANY-approved, portable high voltage electronic holiday detector, with an audible and visual signaling device, and shall test all field joint coatings immediately after application, for discontinuities, holidays and pinholes, in strict accordance with NACE RP-02-74. CONTRACTOR shall submit details of the proposed inspection equipment and inspection procedures prior to start of work, for COMPANY for approval, including:

· Type and make of calibrating voltmeter.

· Grounding techniques for detector and pipe.

· Type of search electrode (steel spring, wet sponge or conductive rubber).

· Applied output voltage, with a spark discharge at least twice coating thickness, to assure adequate inspection voltage and compensate for coating thickness variations.

6.3 The holiday detector shall be calibrated every twelve (12) hours, or upon noticeable humidity change, with a CONTRACTOR furnished voltage meter, and by use on a control joint coating with known holidays.

6.4 CONTRACTOR shall visibly inspect all field joints for wrinkles, air pockets, adhesive flaw and correct heating in accordance with sleeve manufacturer’s thermochromatic indicators. CONTRACTOR shall reject, remove and replace heat-shrink sleeves if:

· Air pockets are apparent

· Wrinkles are visible

· Overlap with the factory-applied anti-corrosion coating is less than 50 mm

6.5 The maximum number of holidays shall not exceed two (2) per field joint coating area or as recommended by supplier and as detailed in CONTRACTOR’s approved procedure.

6.6 CONTRACTOR shall submit for approval as part of the procedures, repair criteria for cuts in the heat shrink sleeve and repair of holidays.

7. FIELD JOINT INFILL APPLICATION

Following field joint anti-corrosion coating application, the field joint cavity shall be completely filled with composite urethane to the same thickness as adjoining concrete coating.

CONTRACTOR shall include as part of the procedures, suitable methods of storage of infill material. Storage methods will prevent contamination or deterioration of the material and will be in accordance with supplier recommendation.

7.1 Composite Urethane Infill

Composite urethane joint infill shall be Flotec FJ4000 or COMPANY-approved equal. Following acceptance of field joint coating, the field joint cavity shall be completely filled with composite urethane infill to the same level as the concrete coating.

CONTRACTOR shall propose a suitable mold to fit around the pipe and contain composite urethane infill material.

Infill material shall be applied in accordance with manufacturer’s recommendations and to COMPANY satisfaction.

Composite urethane shall have cured sufficiently to ensure sufficient strength to support the pipe prior to moving the field joint over any rollers.

8. RECORDS

CONTRACTOR shall maintain records of all field joint inspection results and relate the results to each specific field joint number. Material batch numbers and certificates shall also be related to a specific field joint number.

On completion of the WORK, CONTRACTOR shall submit the following information as a minimum to COMPANY:

· Heat-shrink sleeve batch certificates

· Heat-shrink sleeve inspection records

· Holiday detector calibration certificates

· Infill material batch certificates

· Mold material certificates

· Application equipment calibration certificates

· Infill inspection records

The above data will be supplied in a hard copy format and an electronic format.

FIELD JOINTS