Offshore Pipeline Bracelet Anode | Subsea Cathodic Protection
As a specialized subsea bracelet anode manufacturer, we engineer and supply high-performance galvanic cathodic protection systems for submerged steel pipelines. Split-half and multi-segment configurations clamp directly onto pipeline anti-corrosion coatings, secured by heavy-duty threaded steel inserts and cushioned with high-density backing. Designed strictly to project specifications, these offshore pipeline bracelet anodes mitigate seawater corrosion across critical subsea operating lifespans.
Key Features
Precise Geometry: Custom-molded inner radii match exact pipe outside diameters (OD), insulation thicknesses, and field joint profiles.
Secure Fastening: Recessed bolt pockets and structural steel inserts prevent slippage during subsea installation, heavy trenching, and pull-in operations.
Uniform Current Output: Homogeneous alloy microstructure ensures stable electrochemical potential and predictable consumption rates in marine environments.
Coating Protection: Integrated neoprene or rubber backing shields pipeline field joint and mainline coatings from mechanical abrasion and point loading.
Technical Specifications
|
Parameter |
Zinc Anode (ASTM B418 Type I / II) |
Aluminium Alloy Anode (Al-Zn-In) |
|
Open Circuit Potential |
-1.05 V to -1.10 V (vs. Ag/AgCl/Seawater) |
-1.05 V to -1.15 V (vs. Ag/AgCl/Seawater) |
|
Closed Circuit Potential |
>= -1.00 V |
>= -0.95 V |
|
Current Capacity |
780 A·h/kg (Min) |
1100 to 2500 A·h/kg |
|
Operating Temperature |
Up to 50°C |
Up to 80°C (Standard), >80°C (High-Temp alloy) |
|
Applicable Standards |
DNV-RP-B401, ASTM B418, NACE TM0190 |
DNV-RP-B401, ISO 15589-2, US MIL-A-18001K |
Materials & Available Options
Alloy Composition
- Zinc (Zn): High purity (>99.99%) with tightly regulated iron, cadmium, and aluminum thresholds for marine mud and shallow seawater.
- Aluminium (Al-Zn-In): Indium-activated alloy optimized for cold and temperate marine waters, preventing premature surface passivation.
Insert Material: Structural carbon steel inserts (ASTM A36 / EN S275JR), hot-dip galvanized per ASTM A153 or coated per project spec.
Configuration: Half-shell, three-segment, or four-segment assemblies engineered around pipe diameter limits and handling safety weights.
Backing Mat: Neoprene rubber pads (6 mm standard thickness, customizable durometer) installed between the anode interior and pipe coating.
Applications
Subsea oil and gas transmission pipelines
Offshore export pipelines, flowlines, and trunklines
Deepwater riser base protection systems
Subsea cable crossings and pipeline tie-ins
Offshore wind farm export cables and inter-array pipeline protection
Customization & Extreme Condition Options
Dimensional Adaptation: Custom inner diameters tailored to bare pipe OD plus specific anti-corrosion and concrete weight coating (CWC) tolerances.
Weight Tuning: Exact net metal weight adjustment to satisfy multi-year subsea design life and current demand calculations.
Severe Environment Engineering
- Deepwater High-Pressure: Reinforced structural insert designs preventing crushing under high hydrostatic pressures.
- High-Temperature Operations: Modified Al-Zn-In alloy variations designed for operating temperatures exceeding 80°C.
- Arctic / Polar Waters: Low-temperature impact-tested steel inserts and specialized high-activity alloys.
- Identification: Cast-in heat numbers, alloy designations, and client-specified serial/project stamping.
Quality Control & Manufacturing Capabilities
Manufacturing execution complies with rigorous quality management protocols and recognized marine classification standards:
Spectrochemical Analysis: Direct-reading optical emission spectrometer (OES) verifies exact chemical composition for every melt heat prior to casting.
Casting Process: Permanent mold gravity casting minimizes internal shrinkage cavities and gas porosity.
Electrochemical Testing: Batch sampling tested in certified independent laboratories to verify open/closed circuit potential and electrochemical current capacity.
Dimensional Verification: Coordinate Measuring Machines (CMM) and custom radius gauges check inner diameter, bolt hole alignment, and weight tolerance (± 3%).
Third-Party Inspection: Complete readiness for witnessing and verification by DNV, BV, ABS, SGS, or LR inspectors.
Packaging & Shipping
Palletization: Heavy-duty fumigated wooden skids secured with high-tensile steel strapping, engineered for sea freight and offshore crane staging.
Corrosion Prevention: Exposed steel inserts protected with marine-grade rust preventatives; bolt threads greased and capped.
Documentation Package: Material Test Reports (MTRs per EN 10204 3.1), Certificate of Conformity, and detailed packing lists included with every shipment.
Frequently Asked Questions
Q: How do you prevent damage to the pipeline anti-corrosion coating during subsea installation?
A: Each bracelet anode is fitted with high-density neoprene backing pads inside the shell, absorbing mechanical clamping forces and preventing direct metal-to-coating contact.
Q: What is the standard manufacturing tolerance for anode net metal weight?
A: Net metal weight tolerances are strictly maintained within ± 3% of engineering drawing requirements, verified using calibrated industrial scales prior to palletization.
Q: Can these anodes operate in high-temperature subsea pipeline environments (>80°C)?
A: Yes. For high-temperature operating conditions, specific Aluminium-Indium alloy variants with modified iron and silicon thresholds are utilized to prevent thermal passivation and performance drop-off.
Q: Are steel inserts electrically connected to the pipeline infrastructure?
A: Steel inserts feature dedicated welding tabs or mechanical clamping studs that ensure low-resistance electrical continuity with the pipeline steel, verified via millohm meter testing upon request.
Q: Do you provide Third-Party Inspection (TPI) documentation?
A: Yes. Standard production runs accommodate inspection hold points for TPI agencies such as DNV, Bureau Veritas, and ABS, delivering complete EN 10204 3.1 test certificates.
Q: What is the typical lead time for custom-radius bracelet anodes?
A: Standard pattern development, mold preparation, and casting require 3 to 5 weeks, depending on order volume, alloy specifications, and scheduled TPI verification.
Request a Quote (RFQ)
To receive an accurate technical proposal and commercial quotation for your project, please provide the following parameters:
1.Pipeline Outside Diameter (OD) and Wall Thickness
2.Coating Type and Thickness (FBE, 3LPE, Concrete Weight Coating)
3.Required Alloy Type (Zinc or Aluminium-Indium)
4.Design Life and Operating Temperature / Environment
5.Total Quantity, Required Delivery Schedule, and Destination Port
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