Design Formula for Steel Pipe [49 CFR 192.105]

(A)A. The design pressure for steel pipe is determined in accordance with the following formula. [49 CFR 192.105(a)]#

P=(2St∕D)×F×E×T#

P = Design pressure in pounds per square inch (kPa) gauge#

S = Yield strength in pounds per square inch (kPa) determined in accordance with §907#

D =Nominal outside diameter of the pipe in inches (millimeters)#

t = Nominal wall thickness of the pipe in inches (millimeters). If this is unknown, it is determined in accordance with §909. Additional wall thickness required for concurrent external loads in accordance with §903 may not be included in computing design pressure.#

F = Design factor determined in accordance with §911#

E = Longitudinal joint factor determined in accordance with §913#

T = Temperature derating factor determined in accordance with §915#

(B)B. If steel pipe that has been subjected to cold expansion to meet the SMYS is subsequently heated, other than by welding or stress relieving as a part of welding, the design pressure is limited to 75 percent of the pressure determined under Subsection A of this Section if the temperature of the pipe exceeds 900°F (482°C) at any time or is held above 600°F (316°C) for more than one hour. [49 CFR 192.105(b)]#

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:501 et seq.#

HISTORICAL NOTE: Promulgated by the Department of Natural Resources, Office of Conservation, LR 9:221 (April 1983), amended LR 10:513 (July 1984), LR 24:1308 (July 1998), LR 27:1537 (September 2001), LR 30:1230 (June 2004).#