Page 69 - Estimator's Piping Man-Hour Manual 5E

52 Section One-SHOP FABRICATION

MAdHNING INSIDE OF LARGE O.D. PIPE

Built-Up Ends
Carbon Steel Material

NET MAN HOURS PER END
Machining Inside of Straight Pipe Only I.D. Build-Up
with
O.D. WALL THICKNESS IN INCHES Weld Metal
Pipe
Size .500 to 1.51 to 2.26 to 3.01 to 4.51 to Man Hours
Inches 1.50 2.25 3.00 4.50 6.00 Per End
26 3.74 4.49 5.35 6.84 8.57 12.88
28 4.03 4.83 5.75 7.25 9.03 15.24
30 4.49 5.18 6.15 7.71 9.55 19.26
32 4.95 5.75 6.50 8.22 10.18 23.58

34 5.58 6.27 7.13 8.80 10.70 29.67
36 6.27 7.02 7.76 9.32 11.27 35.31
38 7.02 7.82 8.63 10.00 11.90 41.40
40 7.82 8.63 9.55 10.70 12.59 48.36
42 8.68 9.37 10.47 11.39 13.34 56.70
44 9.49 10.41 11.39 12.25 14.03 65.67
46 10.41 11.27 12.36 13.23 14.89 74.00
48 11.39 12.25 13.28 14.15 15.76 83.43
54 12.81 13.78 14.94 15.92 17.73 93.86
60 14.24 15.31 16.60 17.69 19.70 104.29

Machining: Man hours for machining the inside of straight pipe are for any taper bore from 10" through 30'
included angle. For machining the ends of bends add 100% to the above man hours. For counterboring (up
to a maximum of 2" in length), add 50% to the above man hours. For machining to a controlled "C"
dimension (as required for power piping critical systems), add 225% to the above man hours.
Cutting and Beveling: Man hours do not include cutting and beveling. See respective tables for these charges.
Built-Up Ends: Man hours for built-up ends are for building up the I.D. of straight pipe, bends or fittings, at the
ends with weld metal and grinding where it is necessary for proper fit of backing rings.