Primary Use
Magnesium alloy sacrificial anodes (magnesium anodes) are suitable for anticorrosion protection in projects such as oil and gas transmission pipelines, water supply and drainage pipelines, underground cables, chemical industry, communication, harbors, ships, reservoir gates, and other underground freshwater environments.
Standard: GB/T 17731-2009
Chemical Composition
Buried pipeline/Storage tank exterior wall and underground metal structures commonly use sacrificial anodes (magnesium anodes) models and specifications
Anode (Magnesium Anode) Installation Method
1Anode Ground Bed Structure
To ensure the stable performance of the sacrificial anode (magnesium anode) in the soil, appropriate chemical backfill materials must be filled around the anode. The adjacent soil is to the anode as the adjacent material is to the anode, which improves the working environment of the anode; reduces the anode's grounding resistance, and increases the anode's output current; the chemical composition of the backfill promotes the dissolution of anode products, prevents scaling, reduces unnecessary anode polarization; and maintains a long-term moist anode bed. The basic requirements for the chemical backfill material include:
Low resistivity, good permeability, not prone to leach; excellent moisture retention. Sacrificial anode filling material can be packed in bags or filled during on-site drilling. Note that the bags for packing are made of natural fiber fabrics; synthetic fiber fabrics are strictly prohibited. While on-site drilling filling has good results, it requires a large amount of filling material, and care must be taken to avoid soil particles being mixed in, which can affect the quality of the filling. The thickness of the filling material should be maintained at 5-10 cm in all directions. Common filling material formulations can be found in the attached table:
2Anode Ground Bed Arrangement
The distribution of sacrificial anodes can be in a single piece or grouped together. The anode installation can be either vertical or horizontal, with burial directions including axial and radial. The general burial position is 3 to 5 meters from the pipeline outer wall, with a minimum of 0.3 meters. The burial depth should be such that the top of the anode is at least 1 meter from the ground, especially below the frost line in northern regions. For grouped installations, the spacing between anodes should be 2 to 3 meters. In arid areas with groundwater levels below 3 meters, the anodes should be buried deeper. For river and lake areas, anodes should be buried as close to the riverbed (lake bottom) as possible to prevent damage from flooding and dredging. When using sacrificial anodes in urban and pipeline areas, attention should be given to ensure no other structures, such as cables, water, steam, or pipelines, are between the anodes and the protected structures.
Sacrificial anode (magnesium anode) spacing on pipelines: for long-distance pipelines, 1-2 sets/km; for urban pipelines and in-station networks, 200-300 sets are recommended.
3Appendix Table
