Section 71: Three-piece 90 Degree Elbow with a Round Branch

Required Information

The branch lines will intersect with corresponding lines from the quarter circle Draw lines at 90 degrees to the heel of the elbow from all intersecting points obtained in Draw a 90 degree line to the lines just obtained in From the quarter circle set dividers from 1 to 2 on the vertical lines.

Step 1
Draw a side view of the fitting with insulation included
Step 2
Draw semi-circles at the end of the branch and at the bottom of the 90 degree elbow. Draw two quarter circles at the right side of the Elbow. Use the large radius of the elbow and the radius of the branch
Step 3
Trisect the branch half circle as well as the elbow half circle, also trisect the small quarter circle and label all three as shown. Extend lines as shown in Figure 1. The branch lines will intersect with corresponding lines from the quarter circle
Step 4
Draw lines at 90 degrees to the heel of the elbow from all intersecting points obtained in
Step 5
Draw a 90 degree line to the lines just obtained in
Step 6
From the quarter circle set dividers from 1 to 2 on the vertical lines. Transfer to both sides of Line 1. Do the same from 2 to 3 but go from the last point drawn. Do the same from 3 to
Step 7
Draw parallel lines to Line 1 from the points established in
Step 8
Connect all corresponding numbered points on the lines to obtain the pattern for the hole where the branch will insert
Step 9
The elbow itself can be done in the same manner as all other elbows. I