Fabrication Flashcards
Why are transitional fittings used
Change the ratio
move a duct for architectural reasons
Why are transition fittings avoided
Time
money
What is three joints used to join traditional fittings to each other
Slip and drive
CP connection
propriety connection
What must be done to net pattern for each slip and drive joint connection
Reduce the length of net pattern by 1”
What must be Develop first one developing cheek for a curved runner pattern
The flat view or pattern
The Stretch out lengths for heel runner should be calculated
True
What Mathematical concept is used when building transition from Plainview
Pythagorean theorem
When developing two sided slope transition how do we determine which gets slow pocket allowance
The one with the most amount of slope
On assembling a transition fitting what should be done before assembly
Form seams and edges
Open Pittsburgh lock 
When developing a centred one-way Square to round what is the minimum plan view required
Half pattern on ,centre to Square requires quarter inch plan
How far should your half plan view be drawn from the edge material
At least 1 inch
How do you tell on square to round a inside or outside pattern
If pattern goes ABCD it’s an inside if pattern gose DCBA it’s an outside
To forming an elbow what machine should be used
Rotary elbow machine
What happens when rectangular duct exceeds 4:1
Airflow reduction
What is a standing drive connection
Known as a CP connection requires too allowance to be added to the raw edge
When engineers draw prints what are they drawn to
Net patterns
In what order should fitting be developed
Layout
Brake
Seams
What machine can be used to develop 3/16 male Pittsburgh 
Easy edger power flanger
Do machines for Heavier gauges have different allowances
Yes
If a fitting has three flat sides what is it
Flat rectangle taper
If two sides are flat how many peace’s to fabricated
As one piece
If a transition has no flat sides how many pieces can be made in
Four
When is it advisable to use more than 12 elements on triangulated patterns
Diameters over 12 inches
When laying out a pattern for squared around fitting that is centred you need to lay out only
1/4
Why is the best place all construction lines inside pattern
To make for a cleaner job
If you are making this fitting so the directional air flows gose through the collar it should be manufactured as
Small and allowance collar 
