Page 72 - Estimator's Piping Man-Hour Manual 5E

Section One-SHOP FABRICATION 55

PREHEATING BUTT WELDS AND ANY TYPE
OP FLANGE WELDS
Labor Only

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 0,2 0.3 .. .. 0.2 .. 0.3 „ „ 0.4
2-1/2 0.3 0.4 -- -- 0.3 -- 0.4 -- -- 0.5

3 0.4 0.5 „ 0.4 ,. 0,5 .. 0.6
3-1/2 0.4 0.5 ... -- 0.4 -- 0.5 - 0.8
4 0.5 0.6 -- .. 0.5 -- 0.6 .. 0.8 0.8
5 0.6 0.8 -- - 0.6 - 0.8 .. 0.8 - 0.9
6 0.7 0.9 .. 0.7 .. 0.9 -- 1.1 -- 1.3
8 0.8 1.1 0.8 0.8 0.8 1.1 1.1 1.5 1.6 2.0 2.1
10 1.1 1.5 1.1 1.1 1.1 1.5 1.7 2.0 2.3 2.8 3.2
12 1.3 1.7 1.3 1.3 1.6 1.9 2.4 2.8 3.2 3.7 4.5
1400 1.6 2.1 1.6 1.6 1.9 2.5 3.0 3.7 4.2 4.9 5.6

16 OD 1.9 2.8 1.9 1.9 2.5 3.2 3.8 4.6 5.1 6.2 7.2
18 OD 2.2 3.0 2.2 2.6 3.5 4.2 5.1 5.9 6.7 7.2 8.9
20 OD 2.6 3.5 2.6 3.5 4.4 5.3 6.3 7.4 8.3 9.4 10,9
24 OD 3.1 4.2 3.1 4.5 5.4 6.6 7.9 8.8 9.9 11.3 12.9

Pipe Thickness: The wall thickness of the material determines the man hours that will apply. For preheating of
double extra strong material, use Schedule 160 man hours.
Mitre Welds: For preheating of mitre welds, add 50% to above man hours.
Man Hours: Man hours for preheating are additional to charges for welding operations.
Preheating: For preheating to temperatures above 400°F. but not exceeding 600°F., add 100% to the above man
hours.