How to connect zinc alloy sacrificial anodes to pipelines

Pei Yingying  1862587  9268

The characteristics of aluminum alloy anodes are: high theoretical power generation, low specific gravity, which allows for the design of long-life anodes with light weight, convenient manufacturing, simple production processes, ample material sources, and excellent electrochemical performance. They have the function of initially regulating current and potential and are widely used for the protection of internal marine oil equipment, external submarine pipelines, platform jackets, etc. However, aluminum anodes have the disadvantages of lower current efficiency compared to zinc anodes, poorer dissolution performance than zinc anodes, and unsuitability for high-resistivity media.

Currently, the development of aluminum alloy anodes is moving towards improving current efficiency, enhancing dissolution performance, and adapting to high-resistivity media as well as high and low-temperature seawater environments. For example, to effectively protect offshore oil pipelines, bracelet-type sacrificial anodes are widely used in the eastern South China Sea, making aluminum sacrificial anodes more suitable for installation. The generated current meets the pipeline requirements as much as possible to achieve the desired protection lifespan.

(3) Sacrificial Anode Protection Design

The effectiveness of sacrificial anode protection mainly depends on the sacrificial anode material and a reasonable sacrificial anode protection design. The basic steps are as follows:

1) Collect design parameters.

Gather information on material, surface condition, geometric shape, and relevant environmental conditions. Set the protection current density, understand the protection area and structural characteristics, and calculate the total protection current required based on the protection lifespan.

2) Select sacrificial anode material and specifications.

Based on the protection lifespan and requirements, choose the sacrificial anode material (such as zinc anodes or aluminum anodes). According to installation and structural conditions and the protection current, determine the protection distance of the anode to derive the anode's size and specifications.

3) Calculate the number of anodes and verify.

Pei Yingying   1862587   9268