A “Toolbox” for Forensic Engineers

Fluid Transport
6.1 Introduction
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Among the most demanding roles of any material is that of containing and
transporting fluids. Why? Because escape of the contents due to failure of
the wall can create far more serious damage than the initial break. Fuel spray
from pipe leaks can cause devastating fires, while the damage from corrosive
chemicals from leaking storage tanks can be extensive. Even small losses of
water from supply pipes is serious if undetected, as many homeowners will
know much to their regret from freezing water effects in winter. In supply
systems to larger buildings, the effects are multiplied, and the losses far greater
if equipment is damaged by the leaking water. Design, rather than manufacturing
or assembly, defects in central heating systems (CHS) produce a multiplier
effect of such severity as to seriously affect the credibility of major
companies and corporations. So what are the requirements for containment
materials?
6.2 Materials of Choice
The material of the wall must resist any kind of interaction with the fluid
being contained, as well as the external environment. It thus implies resistance
to corrosion and environmental degradation on both the inner and
outer surfaces. In addition, the material must satisfy several other criteria
and be capable of easy manufacture into both simple (pipe, cylinder) and
more complex shapes (such as connections and joints). Because connections
in piping systems are usually needed on site, welding the parts together is
often a critical operation during construction. The integrity of such joints is
often crucial to the integrity of the entire system, essentially because they are