Page 142 - Estimators Piping Man Hour Manual

Section Two-FIELD FABRICATION 125

PREHEATING LARGE O.D. 00° NOZZLE WELDS

Carbon Steel or Alloy Materials
For Temperatures Up To 400 °F

NET MAN HOURS EACH
O.D. WALL THICKNESS IN INCHES
Pipe
Sizes .500 .750 1.00 1.25 1.50 1.75 2.00 2.25
26 9.7 10.7 12.9 15.6 18.3 20.1 23.0 25.8
28 10.3 11.4 13.8 16.6 19.2 21.2 24.4 27.7
30 10.9 12.2 14.8 17.6 20.5 22.8 26.1 29.5
32 11.6 12.9 15.5 18.5 21.6 24.0 27.5 31.0
34 12.6 13.8 16.3 19.9 23.2 25.7 29.3 33.4
36 13.5 14.8 17.5 21.6 25.7 28.2 32.2 36.5
38 14.3 15.8 18.9 23.0 28.6 31.0 35.5 40,1
40 15.3 17.0 20.2 24.5 31.7 34.2 39.1 44.1
42 16.2 18.1 21.8 26.3 34.0 37.8 43.0 48.5
48 18.5 20.7 24.9 30.1 38.8 43.2 49.1 55.5
54 20.8 23.2 28.1 33.9 43.7 48.5 55.2 62.3
60 23.1 25.8 31.2 37.6 48.5 53.9 61.4 69.3
Pipe Thickness: The size of the nozzle and the wall thickness of the header or nozzle (whichever is greater)
determines the man hours to be used. For preheating of double extra strong thickness use schedule 160
man hours.
Time: For reinforced 90° nozzle welds, add 100% to the above man hours.
For 45° nozzle welds, add 50% to the above man hours.
For reinforced 45" nozzle welds, add 150% to the above man hours.
For preheating to temperatures above 400°F. but not exceeding 600°F., add 100% to the above man hours.
Preheating of coupling, weldolet, threadolet or socket welds should be charged at the same man hours as
shown for the same size and schedule nozzle.
Man hours for preheating are additional to man hours for welding operations.