Page 141 - Estimators Piping Man Hour Manual

124 Section Two-FIELD FABRICATION

PREHEATING 90° NOZZLE WELDS

Carbon Steel, or Alloy Materials
For Temperatures Up To 400"F

NET MAN HOURS EACH
Standard Extra
Pipe Heavy Pipe SCHEDULE NUMBERS
Size & OD Sizes & OD Sizes
Ins. 3/8" Thick 1/2" Thick 20 30 40 60 80 100 120 140 160
2 0.5 0.6 -- 0.5 -- 0.6 -- 0.7
2-1/2 0.6 0.7 .. 0.6 0.7 -- — 0.9
3 0.6 0.9 -- 0.6 -- 0.9 1.0
3-1/2 0.7 0.9 -- 0.7 0.9 -- — ._
__
4 0.9 1.0 _. 0.9 .. 1.0 -- 1.4 -- 1.7
5 1.0 1.4 -- 1.0 -- 1.4 -- 1.7 .. 1.8
—
6 1.3 1.8 -- -- 1.3 -- 1.8 2.0 2.4
— —
8 1.8 2.1 1.7 1.7 1.7 2.0 2.1 2.7 3.1 3.5 4.1
10 2.0 2.7 2.0 2.0 2.0 2.7 3.1 3.8 4.5 -- 5.9

12 2,5 3.3 2.5 2.5 2.8 3.5 4.5 5.2 6.0 _. 8.3
14 OD 3.0 3.8 3.0 3.0 3.5 4.6 5.9 6.6 7.8 10.5
—
16 OD 3.4 4.6 3.4 3.4 4.6 5.9 7.2 8.5 9.8 ._ 13.7
18 OD 4.2 5.5 4.2 4.8 6.3 7.9 9.6 10.5 12.7 ._ 17.0
20 OD 5.0 6.5 5.0 6.5 8.3 10.1 11.8 13.7 15.6 ._ --
24 OD 6.0 7.8 6.0 8.5 10.3 12.5 15.1 16.5 18.9 --
—
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.