Cathodic Protection      
undertank
oil tanks

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:

MMO anode anodes on pipe cathodic protection

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