Nace CP 1, Course Manual

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Installing C.P. Components 8:14
CP 1 – Cathodic Protection Tester Course Manual
©
NACE International, 2000
07/01/04
Before using exothermic welding equipment, become familiar with the
manufacturer’s Material Safety Data Sheets (MSDS) and follow all of the
manufacturer’s recommended safety procedures.
While there are other methods of welding a wire to a structure, these may
cause embrittlement of wire or structure. Brazing should not be used as the
heat is too concentrated and may cause damage to both the wire and the
structure.
Mechanical
Mechanical connections are used typically in places where flammable or
explosive conditions preclude the use of thermite welding and also in
places where connections are made above ground. Underground mechanical
connections are usually made with a clamp and conductive epoxy.
Above ground connections may be made using lugs attached to the end of
the wire or cable. The lugs can then be bolted to the structure.
Coating
All wire and cable attachments should be coated with electrically insulating
material. If the structure is coated, the insulating material must be
compatible with the coating on the structure. It is especially important to
coat above ground connections where brass lugs are bolted to steel
structures to prevent galvanic corrosion.
Galvanic (Sacrificial) Anodes
General
Galvanic anodes operate because of the galvanic (dissimilar metal) reaction
between the anode and the structure. Hence the name,
galvanic anode .
These anodes are also called sacrificial because they may be thought of as
sacrificing themselves to protect the structure.
It is important that galvanic anodes be installed according to construction
specifications. Improperly installed anodes will very likely not function
properly.