Textron GREENLEE 885 - Segment Bend Calculations and Layout; Developed Length Formula and Table

884 and 885 Hydraulic Benders
Greenlee / A Textron Company 4455 Boeing Dr. • Rockford, IL 61109-2988 USA • 815-397-7070
11
Bending Instructions (cont’d)
Laying Out a Segment Bend (cont’d)
Developed Length Formula
Use the following formula to calculate the developed length for any bend:
developed length = 0.01744 x degree of bend x bending radius
Developed Length for 90° Bend Table
Radius—
Increments by Tens
Radius—Increments by Ones
0 1 2 3 4 5 6 7 8 9
0 0 1.57 3.14 4.71 6.28 7.85 9.42 10.99 12.56 14.13
10 15.70 17.27 14.84 20.41 21.98 23.85 25.12 26.69 28.26 29.83
20 31.40 32.97 34.54 36.11 37.68 39.25 40.82 42.39 43.96 45.53
30 47.10 48.67 50.24 51.81 53.38 54.95 56.52 58.09 59.66 61.23
40 62.80 64.37 65.94 67.50 69.03 70.65 72.22 73.79 75.36 76.93
50 87.50 80.07 81.64 83.21 84.78 86.35 87.92 89.49 91.06 92.63
60 94.20 95.77 97.34 98.91 100.48 102.05 103.62 105.19 106.76 108.33
70 109.90 111.47 113.04 114.61 116.18 117.75 119.32 120.89 122.46 124.03
80 125.60 127.17 128.74 130.31 131.88 133.45 135.02 136.59 138.16 139.73
90 141.30 142.87 144.44 146.01 147.58 149.15 150.72
To use the table above, nd the intersection of the
appropriate row (“tens” digit of the radius) and appropri-
ate column (“ones” digit of the radius) to determine the
developed length.
Example: 46" radius
Find the appropriate row: 40
Find the appropriate column: 6
Find the developed length
at that intersection: 72.22
To Locate the Center of a 90° Bend
TO BOTTOM OF PIPE
Measure and mark the length of the stub. Subtract the
radius of the bend and 1/2 of the O.D. of the pipe. Add
1/2 of the developed length.
Example: 60" stub 46" radius 90° bend
Developed length: 0.01744 x 90 x 46 = 72.2
1/2 of developed
length: 72.2 x 1/2 = 36.1
Center mark: 60 – 46 – 1.18 + 36.1 = 48.92
CENTER BENDING MARK
48.92"
Suggested Number of Bends Table
Radius
Suggested Number of Bends*
Minimum Maximum
4" to 10" 2 3
10" to 20" 3 5
20" to 30" 5 9
30" to 40" 9 13
40" to 50" 13 19
50" to 60" 19 25
* The minimum and maximum number of bends are suggestions
only. Using a larger number of bends will produce a smoother
segment bend.