Cathodic Protection Engineering And Service——General Introduction
Investigation and plan + Construction + Operation and Maintenance = Cathodic Protection Engineering and Service
Our experienced engineers can provide engineer design, construction and debug service for the cathodic protection of buried pipelines, storage tanks, stations, and petrochemical refineries. Supported by the resource and channel advantage, we can even provide you with one-stop service including design, purchase, installation, debug and operation by EPC mode.

Part 1 Investigation and Plan

The investigation and evaluation of corrosion environment—Introduction
Our experienced engineers can provide engineer design, construction and debug service for the cathodic protection of buried pipelines, storage tanks, stations, and petrochemical refineries. Supported by the resource and channel advantage, we can even provide you with one-stop service including design, purchase, installation, debug and operation by EPC mode.
Design of Cathodic Protection Plan—Introduction
Cathodic protection belongs to electrochemical protection. It uses external current to cause the changes in the metal corrosion potential to reduce corrosion rate. Cathodic Protection is divided into impressed current cathodic protection and sacrificial anode cathodic protection. Before the design of cathodic protection plan, take into account scale of project, construction environment, soil condition, anti- corrosion layer quality and choose the cost-optimal way. In some special environment, these special environmental factors should be taken into consideration such as high temperature, fall of anti-corrosion layer, heat insulating layer, shielding effect of surrounding electronic metal facilities.
Project introduction—Standards and specifications—design principles—cathodic protection design—construction requirements—system management and maintenance

Part 2 Construction

The cathodic protection construction requires knowing the project, setting the reference of construction, preparation of contruction, site construction, commissioning and operation.
01
Knowing the project
To understand the project environment, prepare the construction schedules according to the site condition
02
setting the construction reference
Construct as per national standard and industrial standard
03
construction preparation
Technology preparation/ material approval/ site preparation
04
Site construction
Installation of power supplies, auxiliary anode, junction box and test post ; cable laying
05
Commissioning and Operation
When all is ready, operation can be done.

PART3 Operation and Maintenance

System test and evaluation—Introduction
In order to ensure that cathodic protection is always in good condition, besides common inspection, other comprehensive test should also be conducted: potential to ground, soil resistance, insulation coating resistance, AC stray current, cathodic protection current, stray current flow.
A/Measure of self potential
The frequency and amount of AC and DC stray current can be measured by testing the natural potential. Related electric drainage measures will prevent the metal structure from corrosion and ensure the effectiveness of cathodic protection system
B/Measure of cathodic protection potential
To stop the corrosion process, the cathodic protection potential of the protected structure will be in the range of -0.85V to -1.5V. The measure of cathodic protection potential is to judge the protection status. If too small, it will not work. On the contrary, the anti-corrosion layer will fall off.
C/Measure of ground resistance
If the ground resistance is way much , the whole cathodic protection system will not work normally and the structure will corrode.
D/Test of AC or DC stray current
The stray current is usually from the surrounding railway, power plant, transformer substation, high voltage grounding device. The stray current will flow along with the pipe when it enters the pipeline. The point where it flows out will corrode. The degree of corrosion depends on the current amount and density, geographic position and coating thickness.
E/Test of insulativity of insulation flange
The insulativity of insulation flange influences the electrochemical corrosion of non-protected pipeline. If the insulativity is not good, the cathodic protection current will enter the non-protected section of pipeline and cause the electrochemical corrosion. It will also cause the under-protection of the protected section of pipeline. Therefore the test of insulativity of insulation flange is necessary.
Technology management and service—Introduction