Steps for a 45-Degree Equilateral

Snowman's Notes · pages 83-84 · PDF subsection

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Page 83

Steps for a 45-Degree

Equilateral

Information Required: ODI, Circumference

Step 1: Draw a horizontal line with a 0—

degree vertical center line and where they

intersect draw a half-circle using half the

ODI

Step 2: Trisect or bisect the semi-circle into

equal parts from the horizontal line draw

90-degree lines up through these trisected

or bisected points of the semi-circle. Label

these lines.

Step 3: Using the radius set at half the ODI

do one walk-up on line 1 and 3 walk-ups on

line 7. Connect those points and label them

as points A and B as shown in figure 1.

Step 4: Where the line drawn from 1 to 7

intersects with the center line. Label that

point C

Step 5: Set dividers at points A and C and do

1 walk-up on the center line from point C to

form point D.

Step 6: Connect these points going through

A to D then to B.

Step 7: Continue the vertical lines from the

arc points to lines A, D and B.

Step 8: For half the stem portion of the

fitting take half the circumference and

divide that into 6 equal points. Label as

shown in figure 2.

Step 9: Measuring from the base line to the

A-D-B line, measure each line and transfer

that measurement to the corresponding

lines on the sketch-out and connect all of

these points.

Step 10: Draw a 90-degree horizontal line

from line 1 to line 7 making sure to

intersect with line 4 (center line) as shown

in figure 2. Save the portions as shown for

the other portion of the fitting add a lap

allowance.

Step 11: Using the cross-hair method, apply

the pieces saved from step 10 to the cross-

hairs as shown in figure 3. This will be the

hold-cut-out. Add a lap allowance as

required.

Page 84

Unequal Laterals

Required Dims: OD Both pipes, OC both

pipes (Ins included).

Working Drawing

1. Draw the working drawing. Start with the centerline of

the large pipe (Top portion not required).

2. Draw a secondary projection downward form the body

portion an d divide, carry division lines up to

the body portion connecting at the arc, then

across and down the pre-divided tee portion.

Tee Portion

1. Cut a piece of metal equal to the OC of the small pipe +

LAP and Divide.

2. Using dividers transfer small pipe reference points to

the stretch-out.

Body Portion

1. Cut a piece of metal equal to the large OC + LAP

2. Set dividers to along the large arc that were generated

from the secondary projection. Transfer these

individual widths into the circ of the metal.

3. Transfer the dimensions from the body portion of the

working drawing. Take all dims from one side.

#5 goes on line #3, #6 on #2, and #7 on #1.

Reference

Lines

Tee

Portion

76 1

7 6