Magnesium Anode (R Type)
Magnesium anodes are a widely used solution for corrosion control when impressed current cathodic protection is not an appropriate or feasible option for the intended facilities.
Bare magnesium anodes are most commonly used anode for applications in soil. The greater negative potential of the magnesium anode results in a high driving voltage which allows the anode to supply sufficient protection to underground steel structure in soil with medium to high resistivity (1,000 – 10,000 Ω·cm).
Our bare magnesium anode is usually made into two types with differing electrode potential (relative to Cu/CuSO4 reference electrode). They can be used to protect most buried metallic structures found in a range of soil resistivities. High potential magnesium anode are often utilized in dry or resistant earth, or where increased current is needed due to a poorly coated tank. Standard potential magnesium anodes perform well in corrosive soil, if the tank is well coated, and in this case will last longer than the high potential alloy.
Additional information
| Application | Pipelines, Storage Tank |
|---|---|
| Environment | Fine Sand, Soil |
Description
Description
Quality Substrate Material
Our magnesium anode is manufactured under the ASTM B843-M1C standard for high potential or ASTM B843-AZ63B standard for standard potential, according to the following composition:
| Element | High Potential (ASTM B843 - M1C) | Standard Potential (ASTM B843 - AZ63B) |
| Aluminum (Al) | 0.01% | 5.3 – 6.7% |
| Manganese (Mn) | 0.5 – 1.3% | 0.15 – 0.7% |
| Zinc (Zn) | — | 2.5 – 3.5% |
| Silicon (Si) | 0.05% | 0.1% |
| Copper (Cu) | 0.02% | 0.02% |
| Nickel (Ni) | 0.001% | 0.002% |
| Iron (Fe) | 0.03% | 0.003% |
| Other Each | 0.05% | — |
| Others Total | 0.3% | 0.3% |
| Magnesium (Mg) | Remainder | Remainder |
Different Electro-potential Options
There are two common cast magnesium anode available:
1. Standard Magnesium Alloy Anode
A standard potential anode has a nominal corrosion potential of -1.55 volts (relative to a Cu/CuSO4 reference electrode). It is ideal for soil conditions where resistivity is under 20 Ω·cm.
2. High Potential Magnesium Alloy Anode
High potential magnesium anodes have higher open circuit voltage and driving potential. It produces an open circuit potential of negative 1.7~1.75 volts, which is 20~30% greater than is typically found with conventional magnesium anodes. This yields more current output and achieves a greater efficiency; reaching a sufficient cathodic protection level whilst maintaining a lower consumption of the anodes. They are ideally suited for structures buried in soils with resistivities exceeding 2,000 Ω·cm, or for structures containing numerous corrosion clusters.
| Technical Measurement | High Potential | Standard Potential |
| Open Circuit Potential (-V) | 1.7 ~ 1.75 | 1.5 ~ 1.55 |
| Close Circuit Potential (-V) | 1.58 ~ 1.62 | 1.45 ~ 1.50 |
| Min. Current Capacity | 500 A.h/lbs (1100 A.h/kg) | 550 A.h/lbs (1230 A.h/kg) |
| Min. Current Efficiency | 50% | 55% |
Remarks: Open/close circuit potential is with respect to a Saturated Calomel Reference Electrode.
Parameters
Standard sizes below are available at Jennings Anodes warehouse. Other sizes are available upon request.
| Item No. | Anode Dimensions ( ØD x L ) | Insert Dimensions | Anode Weight | ||
| High Potential | Standard Potential | Wc | T | ||
| JA-MG-R50 |
Ø4.5” x 11.3”
(Ø114 x 288 mm) |
Ø4.5” x 10.8”
(Ø114 x 275 mm) |
1.0”
(25 mm) |
0.08”
(2 mm) |
11 lbs
(5 kg) |
| JA-MG-R77 |
Ø4.5” x 17.3”
(Ø114 x 440 mm) |
Ø4.5” x 16.1”
(Ø114 x 410 mm) |
1.0”
(25 mm) |
0.08”
(2 mm) |
17 lbs
(7.7 kg) |
| JA-MG-R100 |
Ø4.5” x 22.2”
(Ø114 x 565 mm) |
Ø4.5” x 21.5”
(Ø114 x 545 mm) |
1.0”
(25 mm) |
0.08”
(2 mm) |
22 lbs
(10 kg) |
| JA-MG-R145 |
Ø5.75” x 19.9”
(Ø146 x 505 mm) |
Ø5.75” x 18.7”
(Ø146 x 475 mm) |
1.0”
(25 mm) |
0.08”
(2 mm) |
32 lbs
(14.5 kg) |
| JA-MG-R273 |
Ø4.5” x 60”
(Ø114 x 1524 mm) |
Ø4.5” x 57.1”
(Ø114 x 1450 mm) |
1.0”
(25 mm) |
0.08”
(2 mm) |
60 lbs
(27.3 kg) |
Testing Details
We employ ISO 9001:2015 quality management system and rigorous internal testing standards to ensure the optimum lifespan and performance of our anodes. Each anode is labelled with a unique serial number for quality tracking.
| Technical Measurement | Chemical Composition | Electrochemical Performance | Physical Properties |
| Testing Standard | ATSM A518 (Gr1) | ATSM A518 (Gr3) | Foundry ITP |
| Testing Content | Chemical Analysis | Circuit Potential / Anode Resistance / Current Efficiency | Surface Finish / Dimension & Weight / Steel Core / Cable Connection / Sealing / Backfill Packaging |
| Equipments | Optical Emission Spectrometer OBLF QSN 750 | Electrochemical Analyzer EPI 200 | Calibrated Digital Measuring Devices |
Packaging Information
| Item No. |
Anode Qty
(per pallet) |
Pallet Dimensions
(L x W x H) |
N.W. | G.W. |
Pallet Qty
(per 20ft. container) |
| JA-MG-50R | 50 | 43” x 35” x 42.5” (1100 x 900 x 1080 mm) | 2500 lbs (1135 kg) | 2545 lbs (1155 kg) | 18 |
Remarks: Custom packing is available upon request.
We have strict packing protocols to guarantee safe delivery of our products. Clear shipping marks and documentation make delivery acceptance straightforward and simple.
Shipping Documents:
- Proforma invoice
- Packing list
- Testing reports (Chemical Composition, Electrochemical Properties Test, Certificate of Compliance)
- Certificate of origin (upon request)
