Section 21: Formula for an Unequal Tee

Required Information

• O.D.I.

Formulas and Measurements

• Draw both views as shown in Figures 1 and Trisect the top quarter circles as shown Extend lines down to intersecting points on the lower quarter circles Divide the 1/2 circumference by 6 and draw a Stretch-out as shown in Figures 3 and 4.
• The reason to divide the 1/2 circumference by 6 is because there are 3 equal divisions in a quarter circle.
• To obtain the number of divisions in a full circle, multiply 3 x From the measuring lines, measure to intersecting points on the bottom arcs.

Procedure

1. Step 1

   Draw both views as shown in Figures 1 and

2. Step 2

   Trisect the top quarter circles as shown

3. Step 3

   Extend lines down to intersecting points on the lower quarter circles

4. Step 4

   Divide the 1/2 circumference by 6 and draw a Stretch-out as shown in Figures 3 and 4. The reason to divide the 1/2 circumference by 6 is because there are 3 equal divisions in a quarter circle. To obtain the number of divisions in a full circle, multiply 3 x

5. Step 5

   From the measuring lines, measure to intersecting points on the bottom arcs. Transfer to corresponding numbered lines to the Stretch-out

6. Step 6

   Connect all points to form the stem portions of the fittings. Add lap allowances where needed. -