Construction Plan for Aluminum Alloy Sacrificial Anode

Pei Yingying   186258    79268

Zinc Anode Strip Installation Procedure

① First, straighten the zinc anode strip on the ground. If the ambient temperature is too low during uncoiling, avoid sudden or excessive bending; uncoil slowly to prevent the zinc anode strip from breaking. Cut it to the specified length according to design requirements.

② Check the surface of the zinc anode strip for oil stains, and remove any debris with a cloth or sandpaper.

③ Using tools such as a hacksaw and pliers, strip 20mm of the iron core from both ends of the zinc strip. Polish the iron core with sandpaper and cover it with a heat-shrink tube.

④ Strip 20mm of the copper core from the cable. Use a copper tube with an inner diameter of φ5mm×40mm to sleeve the iron core and the copper core of the cable, then crimp it with a hydraulic crimper. Use a multimeter to check the conductivity at the connection; the contact resistance should not exceed 0.01Ω.

⑤ Seal the joint with tape and tighten it with a heat-shrink tube.

⑥ According to design requirements, lay the zinc anode strip beside the pipeline or wrap it around the pipeline, and connect the cable as required.

⑦ Spread backfill material around the zinc strip, or mix the backfill into a slurry on the ground and fill it around the zinc strip.

The construction method for magnesium strips is the same as for zinc strips. When using magnesium strips to protect tank bottoms, a galvanized flat iron can extend from the center of the tank to the outer side of the tank bottom, and the iron core of each loop of the magnesium strip can be welded to the flat iron.

12.3 Installation of Cathodic Protection Power Supply Equipment

12.3.1 Installation Location of Potentiostat

① There should be no equipment near the potentiostat that obstructs ventilation or affects heat dissipation. When installing the potentiostat, handle it gently and carefully. During wiring, check whether the power supply matches the rated voltage of the potentiostat. In hazardous areas, such as tank farms, rectifier power supplies should be used; in most cases, rectifier power supplies are installed in instrument rooms.

② Wire according to the wiring diagram. The output power polarity should be correct. Mark "+" and "-" on the terminals. Use a multimeter to check the correctness of the terminals. Only after a trial power-on should the cable joints be sealed. After the equipment is installed, the equipment casing must have good grounding performance.

③ Before powering on the potentiostat, first measure the natural potential of the pipeline. This value should be around -0.60V (for pipelines with temporary cathodic protection, this value may reach -1.10V or even more negative). Then measure the natural potential of the anode ground bed. For anodes wrapped in coke backfill, the potential value is between +0.20 and +0.30V (CSE) (if the backfill is pre-packaged in a galvanized iron plate cylinder, the potential may reach -0.90V). The potentiostat will only output current when the set potential is lower than the natural potential of the pipeline. If the ground potential of the cathode and anode cables (positive and negative cables) is very low [e.g., -0.2 to -0.3V (CSE)], or if there is output voltage but no output current, it generally indicates an open circuit in the cathode or anode cables.