Environmental Engineering Reference
In-Depth Information
that dissolves the plastic. The tube ends are firmly pressed together,
and as the plastic hardens they are securely joined. For heat fusion, the
tubes are held against a hot plate. When molten, the ends are joined and
the operation is complete.
4.11 indusTrial hoses
Earlier we described the uses and merits of piping and tubing. This
section describes industrial hoses, which are classified as a slightly dif-
ferent tubular product. Their basic function is the same, however, and
that is to carry fluids (liquids and gases) from one point to another. The
outstanding feature of industrial hose is its flexibility, which allows it
to be used in applications where vibrations would make the use of rigid
pipe impossible. Most wastewater treatment plants use industrial hoses
to convey steam, water, air, and hydraulic fluids over short distances. It
is important to point out that each application must be analyzed indi-
vidually, and an industrial hose must be selected that is compatible with
the system specification.
In this section, we study industrial hoses—what they are, how
they are classified and constructed, and the ways in which sections of
hose are connected to one another and to piping or tubing. We will also
read about the maintenance requirements of industrial hoses and what
to look for when we make routine inspections or checks for specific
problems.
Industrial hoses, piping, and tubing all are used to convey a variety
of materials under a variety of circumstances. Beyond this similar abil-
ity to convey a variety of materials, however, differences do exist among
industrial hoses, piping, and tubing; for example, in their construction
and in the advantages they offer, industrial hoses are different from
piping and tubing. As mentioned, the outstanding advantage of hose is
its flexibility; its ability to bend means that hose can meet the require-
ments of numerous applications that cannot be met by rigid piping and
some tubing systems. Two examples of this flexibility are camel hose,
which is used in wastewater collection systems to clean out intercep-
tor lines or to remove liquid from excavations where broken lines are
in need of repair, and the hose that supplies hydraulic fluids used on
many forklifts. Clearly, rigid piping would be impractical to use in both
situations.
Not only is industrial hose flexible but it also has a dampening
effect on vibration. Certain tools used in wastewater maintenance activi-
ties must vibrate to do their jobs. Probably the most familiar such tool
is the power hammer, or jackhammer. Obviously, the inherent rigidity of
piping and tubing would not allow vibrating tools to last very long under
normal operating conditions. Other commonly used tools and machines
in wastewater operations have pneumatically or hydraulically driven
components. Many of these devices are equipped with moving members
that require the air or oil supply to move with them. In such circum-
stances, of course, rigid piping could not be used.
