1. GENERAL

This specification defines minimum quality and technical standards governing installation, inspection and testing of aluminum bracelet anodes used in offshore pipelines. This specification is to be used in conjunction with the following documents:

· Basis of Design 84506-60-30-2L-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 84506-60-30-2L-270 - Handling, Storage and Transportation of Linepipe

· General Specification 84506-60-30-2L-280 - Aluminium Bracelet Anodes

· BS 4515 – Process Welding of Steel Pipelines on Land and Offshore

· DNV OS-F101 – Submarine Pipeline Systems (2000)

· NACE RP-0492-99 – Acceptance Criteria for Cracks in Cast Anodic Materials

2. BRACELET ANODE REQUIREMENT

CONTRACTOR shall submit for COMPANY approval, a bracelet anode installation procedure, incorporating details of actual equipment and materials to be used. Anodes required on concrete coated pipes shall be installed at the coating plant. Bracelet anodes shall be manufactured in accordance with Project Specification for Aluminum Bracelet Anodes 84506-60-30-2L-280.

3. INSTALLATION PROCEDURES

Anodes shall be clamped around the anti-corrosion coated pipe. Electrical continuity between the anode and the pipe shall be facilitated by anode bonding cables.

3.1 Prior to bracelet anode assembly on the pipe joint, all internal anode surfaces shall be inspected for any dirt, foreign material, grit or metallic protrusions that could damage the anti-corrosion coating. Any such deleterious material shall be removed.

3.2 Bracelet anodes shall be positioned in the approximate center of the pipe and with the gaps between anode halves approximately at ninety degrees (90^o) to the pipe longitudinal seam (if present).

3.3 The anode halves shall be clamped tightly to the pipe using ratchet webbing straps or COMPANY-approved equivalent and the steel tabs fillet welded together. Anti-corrosion coating shall be protected with heat resistant material when tabs are welded. Welders performing the fillet weld shall be qualified in accordance with DNV OS-F101.

3.4 During fit-up, CONTRACTOR shall visually inspect for cracks in accordance with NACE RP-0492-99, Section 3, Clause 3.10.

3.5 Bonding cable connection areas on the pipe shall be selected so that the connected cable lies flat against the pipe and near the center of the anode gap. The connection area shall be completely cleaned of anti-corrosion coating over an area of approximately 50 mm x 50 mm, and the bare steel shall be bright, clean and dry. Anode steel tab connection areas shall be bare and cleaned in a similar manner.

3.6 Bonding cable insulation shall be removed, to provide bare conductor surfaces, over a minimum 50 mm from both cable ends.

3.7 Bonding cables shall be connected to the pipe and anode using Thermit welding. Thermit welds shall be made using manufacturer's recommended procedures, however, no exothermic welding charge greater than 15 gram is permitted, and care shall be taken to keep weld areas and weld molds dry. Slag shall be removed from weld molds prior to each weld and molds shall be fully cleaned every six (6) welds.

3.8 Each of the two half shell bonding cables at each anode assembly shall be connected separately to the pipeline.

3.9 Technicians that are to apply Thermit welding shall be qualified by making at least three attachments to similar pipe. The welds will be destructively tested and sectioned in accordance with BS 4515. Hardness values shall not exceed 270 HV10.

3.10 External anode faces shall be cleaned of all materials, including anti-corrosion coating.

3.11 Anode numbers shall be identified against the pipe numbers in CONTRACTOR records. CONTRACTOR tally system shall separate anode from plain pipe.

4. INSPECTION AND TESTING

Each anode and bonding cable attachment shall be inspected for electrical continuity and mechanical strength before re-coating, as directed by COMPANY. Unsatisfactory bonding cable attachments shall be removed and remade by re-cleaning and re-attaching in a new location.

4.1 The anode shall be clamped tight around the pipe so that it is unable to move independently of the pipe.

4.2 Anode conductor attachment electrical continuity shall be tested with an ohmmeter. Electrical resistance between anode segments and the pipe joint shall show close to zero (0) ohm resistance.

4.3 Mechanical strength of the anode cable shall be checked by a firm side blow from a 1-kg hammer, and then checked visually for any sign of inadequate bonding.

5. CORROSION COATING REPAIR

Following satisfactory anode installation, any damaged anti-corrosion coating shall be repaired and anode bonding cables and exposed core bands coated.

5.1 Anode bonding cable attachment areas shall be thoroughly cleaned with a wire brush. All exposed anode flat bar core bands shall be coated with CONTRACTOR-supplied Synthetic primer type “B” or COMPANY-approved equal. Anti-corrosion coating shall not contact outer anode faces.

5.2 Anode conductor leads shall be held firmly against the anti-corrosion coated pipe joint with cold applied self-adhesive tape (Tapecoat 10/40W or COMPANY-approved equal). The gap between anode half shells and the gap between the anode and concrete coating (if any) shall be filled with marine mastic. The mastic shall be free from aggregate and be approved by Company prior to use. The mastic shall not contaminate the outer surface of the anode. There shall be no voids in the mastic and it shall be flush with the outer anode surface

6. HANDLING, STORING AND SHIPPING

Pipes with bracelet anodes shall be handled in accordance with Project Specification for Handling, Storage and Transportation of Linepipe to prevent pipe coating or anode damage.

7. DOCUMENT SUBMITTALS

CONTRACTOR shall submit to COMPANY for approval the following documents:

a. Description of anode application equipment

b. Anode application procedures

c. Material technical data sheets

d. Field Repair procedures

CONTRACTOR shall submit to COMPANY for approval, a data book comprising:

a. Inspection reports

b. Physical test reports

c. Tally record of anode pipes

d. Material certificates

All certificates shall be in the English language and use metric units of measure. The data book and all associated original documentation shall be approved and signed by the CONTRACTOR and COMPANY Representatives.

All documentation shall be supplied in hard copy and electronic format

PIPELINE ALUMINIUM BRACELET ANODE INSTALLATION