Page 314 - Buried Pipe Design

Chapter
6

Steel and Ductile Iron Flexible

Pipe Products

Steel Pipe

Steel pipe is used in many diverse applications. It is available in vari-
ous sizes, shapes, and wall configurations. For pressure application,
the cross-section is circular. However, for gravity flow, steel pipes can
have cross sections which are vertical elongated ellipses, arch-shaped
for low head room, called long-span arched sections, and other shapes.
For the most part, steel pipes used for gravity applications have a
corrugated wall. The corrugated shape produces a larger moment of
inertia which results in a larger pipe stiffness. Such pipes are usually
galvanized for corrosion protection, but are also available as alu-
minized steel. Common coatings and linings available include bitumen-
type materials, Portland cement-type materials, and polymers. In
certain applications, the lining may be applied after installation. The
linings and coatings are usually ignored in strength calculations.

Corrugated steel pipes

Introduction. The use of corrugated steel pipes as buried conduits has
increased phenomenally since they first appeared on the market about
100 years ago. Both producers and consumers have conducted innu-
merable tests and continual observation since that time. No purpose
could be served here by reviewing the findings. More important are the
design techniques that have evolved from these tests and observations.
At first, corrugated metal pipe design tables showed up with only
the metal thicknesses (gages) available in each diameter. However, a

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