Before inserting another rivet in the tool, be sure
that the broken mandrel has been ejected from the tool.
This can be done by fully extending the lever linkage
and allowing the mandrel to fall clear.
The scissors or expandable type of tool is unique
because it can reach hard-to-get-at areas and can set
the rivets with ease. This tool is particular] y useful for
installing ventilation ducting.
Riveted seams are used for joining metals and
have numerous applications.
Figure 2-90 shows the pattern of one of two pieces
to be joined by lap and rivet. Note the cross section of
the finished seam.
Figure 2-90.Pattern for riveted lap seam.
Figure 2-91 shows the patterns for constructing a
lapped and riveted comer seam. View A is the pattern
for one piece and view B is the other. Note the cross
section through the completed seam.
Frequent use is made of lapped and riveted seams
in joining round pipe sections.
SHEET-METAL DUCT SYSTEMS
With the advent of high-tech equipment, such as
computers and other specialized electronic
equipment, air-conditioning systems are incorporated
more than ever into many Naval Construction Force
(NCF) construction projects. Many of the structures
are designed for long-life usage instead of temporary
buildings with a short time use. There are also some
advanced base functional components (ABFC) which
incorporate heating, ventilating, and air-conditioning
systems (HVAC) within the facility design.
HVAC systems require close coordination
between ratings. Air conditioning, air handling, and
heating units are normally installed by an
Utilitiesman, and the electrical connections are
accomplished by a Construction Electrician. These
items must be installed before the ductwork
installation phase begins. The Steelworker must also
coordinate with the Builder assigned to the project to
ensure that all openings in walls and floors are
sufficient to accommodate ducts, diffusers, and vents.
Sheet-metal HVAC systems require knowledgeable
workers to fabricate and install the various ducts and
Figure 2-91.Riveted seam for tapped and riveted corner seam.