14.2.3 Stray Currents. Small electric currents may stray from sources of
14.2.4 Chemical Attack. The basic action of chemical attack is
electro-chemical; the attack on metals is usually uniform rather than
14.2.5 Microbiological (Tuberculation). This type of corrosion produces
14.2.6 Atmospheric. Corrosion of metals exposed to high humidities (over
70 percent) and high concentrations of airborne sulfur and carbon oxides.
Salt-laden atmospheres are also very common in coastal areas. As naval
installations are usually close to the ocean or other waterways, careful
attention must be paid to the selection of materials used for construction,
surface treatment, concrete reinforcement, electrical conduits, support
structures, piping, and similar components.
14.2.7 Stress and Fatigue. Stress and fatigue of metals usually do not
initiate corrosion, but in most cases they may accelerate it.
Use one of the following methods to
18.104.22.168 Inorganic. The substitution of inorganic materials for metals in
corrosive environments is often desirable; for example, reinforced concrete
pipe and vitrified clay pipe may be used for carrying acids and alkalies in
22.214.171.124 Plastics. The use of chemically synthesized materials as
substitutes for metals must be approved by the NAVFACENGCOM Headquarters.
Plastics and other nonferrous fibers can significantly increase the
toughness of concrete. Refer to NAVFAC DM-3.08, Exterior Distribution of
Utility Steam, HTW, CHW, Fuel, Gas, and Compressed Air, for guidance and
criteria for the use of inorganic piping materials. Refer to the American
Concrete Institute (ACI) 544.1, State-of-the-Art Report on Fiber Reinforced
14.3.2 Passive Metals.
Metals which are passive to their environments may
be used, such as:
c) iron alloys (austenitic gray, high silicon,
iron-chromium-nickel, ni-resistant, ductile),
stainless steels (selective alloys),