Module ID 04301 - Field Measurements, Calculations, and Fittings
Mathematics represents the essence of the sheet
metal craft. Mastery of the mathematical calculations
needed often separates the skilled from
the unskilled. The math required of a sheet metal
craft professional is not abstract nor theoretical.
Instead, it is directly applied to solving work-related
problems and creating each workpiece.
Following a review of important mathematical
concepts, those same concepts will be applied in
this module to creating various offsets and seam
allowances. Unlike straight lengths of duct, offsets
must often be laid out based on field measurements
to fit a specific and unique situation. It is
essential that a craft worker learns how to take
measurements accurately and between the correct
points. (25 hours)
Â
Â
Module ID 04202 - Construction and Sheet Metal Drawings
By the time plans and specifications have made
their way to the construction site, they have been
subjected to considerable scrutiny. Their final form
is the result of numerous negotiations between the
building owner, architect, mechanical engineers,
estimators, and craft professionals to arrive at a
final system design. It is essential that the plans
and specifications are accurately interpreted.
Deviation from the plans or a misinterpretation
could result in having to demolish and reinstall
portions of a system that could lead to a significant
loss for the company. (17.5 hours)
Â
Module ID 04203 - Radial Line Development
Radial line development is a sheet metal layout
method frequently used for the fabrication of fittings
such as cones, reducers, and other tapered
shapes. This module describes the principles of
radial line development and examines how to lay
out and fabricate various sheet metal components
using radial line development techniques. (55 hours)
Â
Module ID 04306 - Triangulation
Triangulation is one of three methods used to lay
out and fabricate sheet metal fittings. More specifically,
it is the process of using trigonometry to
lay out patterns and calculate true line lengths. It
is often used to lay out some of the more difficult
fittings used by sheet metal workers, including
square-to-round fittings, roof collars, stacks and
caps, and fittings that join at unusual angles. This
module describes the triangulation process and
how it is used to develop patterns for fabricating
sheet metal duct fittings. (47.5 hours)
Â
Module ID 04204 - Sheet Metal Duct
Fabrication Standards
To ensure a product of consistent quality and promote
professionalism in the craft, the sheet metal
industry requires standards that identify the best
way to fabricate and install ductwork. In addition
to industry standards, governments at the
local, state, and federal level develop and maintain
building codes in the interest of public safety.
While adherence to industry standards is largely
voluntary, contractors are legally obligated to follow
building codes. (7.5 hours)
Â
Module ID 04206 - Bend Allowances
When metal is bent, a portion of the length of the
flat piece is consumed in the bend. Metal on the
inside of the bend is compressed, while the metal
on the outside is stretched. To make sure the final
piece has the proper dimensions after the bend, an
allowance must be added to the dimensions of the
stretchout to compensate for the distance around
the bend. (7.5 hours)
Â
Module ID 04207 - Soldering
Soldering is a process in which a heated metal
alloy is used as a filler metal to fasten sheet metal
parts, seal seams, and connect piping. To do a professional
soldering job, craftsmen must know how
to prepare the material being soldered, choose the
appropriate materials, and use the required tools.
Because the soldering process involves chemicals
and hot surfaces, it can be hazardous. Craftworkers
must learn how to solder carefully and safely
while making effective, sound joints. Soldering is
a skill that requires practice as well as knowledge.
(15 hours)
Â
Module ID 03109 - Air Distribution Systems
Most heating and cooling systems use ductwork
to deliver conditioned air to the spaces being
cooled or heated. The ductwork may be made of
sheet metal, fiberglass ductboard, fabric, or flexible
duct. The performance of an HVAC system
is closely linked to the quality of the air distribution
system. The ductwork must be of the proper
size and type, and must be correctly installed and
sealed. (15 hours)