Corrosion Control / Cathodic Protection Systems for Onshore Structures
Tanks:
Undertank CP Systems
We provide ICCP systems for any tank whether new build or existing retrofit, these can be laid using a piggyback loop or linear grid array of anodes, these are distributed over the soil side of tank base to ensure uniform current distribution & complete CP of the tank base.
A typical Undertank CP System will include:
- A standard transformer rectifier/power supply unit
- MMO anodes
- Permanent reference electrodes for monitoring
- An undertank tube for ventilation, watering and/or portable measuring
Internal Tank CP Systems
We can design and provide a sacrificial or an impressed current CP system depending on the type of tank. Typically the following apply.
| Tank type |
System type |
Information |
Typical system |
| Water Carrier |
Sacrificial |
Small diameter tanks,
mid-range resistivity |
Aluminum, Magnesium
or Zinc anodes |
| ICCP |
Large diameter tanks
Low resistivity - large current
High resistivity - higher voltage |
MMO Titanium |
| Chemical |
Sacrificial |
Generally not used as products & operating
conditions can be particularly aggressive |
| ICCP-Cathodic |
High current requirement easier to control |
| ICCP-Anodic |
Suitable for low ph & high temps, lower
power
requirements, potential monitoring critical, hard to control |
| Oil product storage tanks |
Sacrificial |
Used for water drop out |
Magnesium or zinc
anodes located on tank floor |
Pipelines:
We carry out a site survey & provide CP systems for buried & submerged pipelines.
As a rule of thumb the following could apply.
| Characteristics |
CP system |
| 0-20 km length |
Sacrificial |
| 20+ Km |
Impressed |
| New plastic coating, new high grade coatings |
Sacrificial |
| Old coatings |
Impressed |
| Corrosive Soil |
Impressed with temporary sacrificial
during construction |
| During pipeline construction phase |
Sacrificial |
Plants:
We supply CP systems for protecting in-plant piping from corrosion. Typically the following apply.
| Characteristics |
Possible systems |
| Small pipeline sections |
Sacrificial |
| Short well coated pipe |
Sacrificial |
| Long lengths |
Impressed |
| Multi pipelines |
Impressed |
| Congested areas |
Impressed – close distributed |
| New pipelines |
Close anode wire |
| Retrofit |
Multi Deepwells or distributed close anode |
