Page 22 - Estimators Piping Man Hour Manual
P. 22
Section One-SHOP FABRICATION 5
Minimum Bending Radii: Man hours shown for pipe bends are based upon a minimum bending radii of 5 nominal
pipe size diameters, with the exception of large sizes and/or lighter walls which must be bent on longer radii.
For bends having a radius of less than 5 diameters add 50% to man hours shown.
Welding Long Bends: When it is necessary to weld together two or more pieces of pipe to produce
the length required in the pipe bend, add the man hours for welding.
Compound Bends: Man hours of pipe bends other than the standard types illustrated or with
bends in more than one plane are obtained by adding together the man hours of the com-
ponent bends that are combined to produce the compound bend.
Bends Without Tangents: For Pipe Bends (Sch. 160 and less) ordered without tangents, add 15%
to man hours shown.
Bends With Long Arcs: For pipe bending with an arc exceeding 10 feet; add 100% to the bending man hours shown
for each additional 10 feet of arc or part thereof.
Connecting Tangents: No. 5 Offset Bends and No. 7 U-Bends are to be considered as such only
when the bends are continuous arcs or if the tangent between arcs of the same radius is
l'-0" long or less. If the tangent between arcs is longer than l'-0", the bends should be
considered as compound bends, i. e., double angle bends, double quarter bends, etc.
No. 9 Expansion U-Bends are to be considered as such only when the bends are continuous
arcs or if the tangents between the "U" and the 90° bends, of the same radius are I'-O" or
less. When such tangents are longer than I'-O" the bends should be man houred as one "U"
and two 90° Pipe Bends. Bends from 181° to 359° should be man houred at the same man
hours as a No. 11 Bend.
Offset Bends: No. 5 Offset Bends are considered as such only when each angle is 90° or less
and the connecting tangents between arcs are within the maximum of I'-O" specified in the
preceding note.
Beveled Ends: If Pipe Bends are to have the ends beveled for welding add the man hours for
beveling.
Thread Ends: If Pipe Bends are to have the ends threaded only, add the man hours for threading.
Flanged Ends: if Pipe Bends are to have the ends fitted with screwed flanges, slip-on weld
flanges, welding neck flanges, or lap joints add the man hours applicable for this operation,
Preparation For Intermediate Field Welds: When Pipe Bends, particularly No. 9,10 or 11, are
too bulky for transporting or handling and therefore, must be furnished in two or more
sections for assembly in the field, an extra charge should be made for the additional cuts
and bevels,
Unlisted Sizes: For unlisted sizes, use the man hours of the next larger shown size.