Section 57: Four-piece Short Radius 90 Degree Elbow w/Negative Throat

Required Information

With a short radius fitting multiply the pipe call-out size times 1 to obtain the Center Line Radius Draw this Center Line Radius and on each side of the Center Line draw an arc showing the actual pipe size Next add the insulation lines (when drawing the insulation lines, notice that the throat is outside the Apex; this is a Negative Throat Fitting.) Label Point A on the vertical line Bisect the 90 degree arc.
Then using a set from the Apex to the outside arc line, set dividers at Point A and mark a Point B on the outside arc.
Mark a set of divider points from the bisection line to Point B and mark a point on the outside arc to form Point C.
Draw a line from the Apex to Point C; extend a little beyond the point Set dividers from the Center Line (where the horizontal and Center Lines intersect) to the O.D.I. line and draw a semi-circle.
Trisect the semi-circle into six equal parts and label as shown Add 3/8" to the Heel and draw this line to the Apex For the Stretch-out, draw a line the length of the circumference and divide that line into 12 equal parts and label as shown Take measurements from Figurel and transfer to the Stretch-out as shown in Figure 2 to the corresponding numbered lines.

Step 1
Draw a 90 degree angle. With a short radius fitting multiply the pipe call-out size times 1 to obtain the Center Line Radius
Step 2
Draw this Center Line Radius and on each side of the Center Line draw an arc showing the actual pipe size
Step 3
Next add the insulation lines (when drawing the insulation lines, notice that the throat is outside the Apex; this is a Negative Throat Fitting.) Label Point A on the vertical line
Step 4
Bisect the 90 degree arc. Then using a set from the Apex to the outside arc line, set dividers at Point A and mark a Point B on the outside arc. Mark a set of divider points from the bisection line to Point B and mark a point on the outside arc to form Point C. Draw a line from the Apex to Point C; extend a little beyond the point
Step 5
Set dividers from the Center Line (where the horizontal and Center Lines intersect) to the O.D.I. line and draw a semi-circle. Trisect the semi-circle into six equal parts and label as shown
Step 6
Add 3/8" to the Heel and draw this line to the Apex
Step 7
For the Stretch-out, draw a line the length of the circumference and divide that line into 12 equal parts and label as shown
Step 8
Take measurements from Figurel and transfer to the Stretch-out as shown in Figure 2 to the corresponding numbered lines. Mark the Points 4 for the start and finish points for the bead and ccccrimp

Next add the insulation lines (when drawing the insulation lines, notice that the throat is outside the Apex; this is a Negative Throat Fitting.) Label Point A on the vertical line.