COST REDUCTION THROUGH CREATIVE CHEMICAL TECHNOLOGY
Technical Data Sheet
OF CLOSED LOOP WATER SYSTEMS
OIL, GREASE, AND IRON OXIDE REMOVAL
Prior to putting a new system into service or returning
one to service after it has been repaired and/or contaminated with oil or
grease, it must be cleaned to remove oil, grease, new pipe mill scale, and
general rust accumulations. Older
systems generally do NOT contain oil. They
are, however, fouled with some hardness related scale, but mostly metal oxide
corrosion by-products. The latter
range from soft, "mud-like" deposits to "hard, encrusted"
iron oxide tubercules. These
contaminants can cause a wide variety of operating problems.
Oil can aggravate corrosion by hindering the ability of chemical
corrosion inhibitors to function and by contributing to the formation of
corrosion cells. Scale deposits can
retard heat transfer, restrict water flow, initiate formation of corrosion
cells, and protect the corrosive actions at existing corrosion cells.
This leads to additional localized corrosion and subsequent leaks.
Scale deposits also hinder the protective action of corrosion inhibitors,
and can provide a "protective home" for corrosive micro-organisms;
particularly acid producing, sulfate reducing bacteria.
Closed loop water systems are typically constructed of
mild steel, copper, and brass metallurgies.
Some may contain galvanized steel, stainless steel, admiralty, and/or
aluminum metallurgies. Thus, highly
alkaline "boil out" procedures typically prescribed by boiler
manufacturer's operating manuals for "all steel" boilers are NOT
acceptable. Cleaning procedures
based on strong, inhibited mineral acids can be risky for some metallurgies, are
hazardous to handle, and are much more difficult to dispose of. The combination
cleaning/passivation products and procedures described below function at pH
neutral to mildly alkaline conditions, and have been found quite successful.
For more, contact CSC Technology for a complete white paper.
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