255.111 - Design factor (F) for steel pipe

 

(a) Except as otherwise provided in subdivisions (b), (c), and (d) of this section, the design factor to be used in the design formula in section 255.105 of this Part is determined in accordance with the following table:

 

Class Location

Design Factor(F)

1

0.72

2

0.60

3

0.50

4

0.40

 

(b) A design factor of 0.60 or less must be used in the design formula in section 255.105 of this Part for steel pipe in Class 1 locations that:

(1) crosses, without a casing, the right-of-way of an unimproved public road;

(2) crosses, without a casing, or makes a parallel encroachment on, the right-of-way of either a hard surfaced road, a highway, a public street or a railroad;

(3) is supported by a vehicular, pedestrian, railroad, or pipeline bridge; or

(4) is used in a fabricated assembly, (including separators, mainline valve assemblies, cross-connections, and river crossing headers) or is used within five pipe diameters in any direction from the last fitting of a fabricated assembly, other than a transition piece or an elbow used in place of a pipe bend which is not associated with a fabricated assembly.

(c) For Class 2 locations, a design factor of 0.50, or less, must be used in the design formula in section 255.105 of this Part for uncased steel pipe that crosses the right-of-way of a hard surfaced road, a highway, a public street, or a railroad.

(d) For Class 1 and Class 2 locations, a design factor of 0.50, or less, must be used in the design formula in section 255.105 of this Part for

(1) Steel pipe in a compressor station, regulating station, or measuring station; and