0010im.jpg)
ETL 1110-9-10(FR)
5 Jan 91
ENVIRONMENT
LENGTH (ft)
Sea Water
3
5
9
Coke Breeze
6
10
20
Fresh Water
30
50
100
Where a specific design requires longer length anodes than
provided for in the above table, the titanium wire or rod
can be provided with a copper core to reduce the effective
resistance. This type of construction has been in use for
over 15 years and has proved to be very durable.
The
titanium wall thickness should be a minimum of 20 percent of
the wire or rod diameter (e.g., for 0.062-in. diameter wire,
the titanium wall thickness should be 0.0124 in., minimum)
The maximum allowable length for copper-core titanium wire
and rod anodes is provided in the table below:
Maximum Anode Length From Connection Point
Copper Cored Titanium Anodes
Anode Diameter
0.062 in.
0.125 in.
0.250 in.
ENVIRONMENT
LENGTH (ft)
Sea Water
7
12
24
Coke Breeze
12
24
54
Fresh Water
70
135
300
A strip anode is presently manufactured as a 3- or 7-ft bar
of ceramic-coated substrate, molded into a multilayer
composite of
fiberglass-reinforced plastic
(FRP)
and
polyurethane 4 or 8 ft long and 4 in. wide that provides
impact resistance,
mechanical support,
and electrical
insulation.
A mesh anode is produced using highly expanded titanium
sheet metal and is used where a large area is to be
protected, where area for anode placement is confined, and
where future access is not practicable. Its use under a
structure's base such as an on-grade tank bottom with
secondary membrane containment or select reinforced
concrete bridges, wharfs, etc., would be appropriate.
Because of its size and the nature of its application, mesh
is generally restricted to use in new facilities.
8
Previous Page
