Shop theory Flashcards
Lap seam allowance?
1W
Groove seam allowance?
3W
Hammerlock allowance?
3W
What type of seam is an elbow seam?
Circumferential
Allowance for a female pittsburg?
15/16”
Male pittsburg allowance?
1/4”
Formula for stretchout?
Diameter x 3.14
What is the purpose for the bead on a pipe?
Add strength and as a stop for the pipe connected to it
What type of seam travels the length of the fitting?
Longitudinal
Formula for small end?
Minus 7MT
How is small end identified?
With a notch
What allowance is added to the net pattern for a slip and drive connection?
1/2”
Ideal length to width ratio for duct?
1 to 1
To what standard is ductwork constructed?
SMACNA
How many views are required to develop the mitre line on a round tee?
2
In which direction should you follow when resistance welding?
Outward to avoid bulging and buckling
What is a crimp used for on a pipe?
Aid in the joining of fittings
The pitch between fasteners is?
The spacing
The 3 methods used to divide a stretchout into 12 equal spaces?
Sloped rule, using dividers and mathematically
What is done to a fish pattern to ensure it is perfect or true?
Truing up the pattern
What is used on a pattern to ensure it finishes at the correct angle?
Centreline
How is the type of seam to be used, determined on a fitting?
Material thickness and pressure class
How many methods are there to developing an offset?
4
Name 3 measurements that are required to develop an elbow?
Throat radius, opening (diameter) and mitre angle