P = (2St/D) * E * F
P = Internal design pressure in p.s.i. (kPa) gage.
S = Yield strength in pounds per square inch (kPa) determined in accordance with paragraph (b) of this section.
t = Nominal wall thickness of the pipe in inches (millimeters). If this is unknown, it is determined in accordance with paragraph (c) of this section.
D = Nominal outside diameter of the pipe in inches (millimeters).
E = Seam joint factor determined in accordance with paragraph (e) of this section.
F = A design factor of 0.72, except that a design factor of 0.60 is used for pipe, including risers, on a platform located offshore or on a platform in inland navigable waters, and 0.54 is used for pipe that has been subjected to cold expansion to meet the specified minimum yield strength and is subsequently heated, other than by welding or stress relieving as a part of welding, to a temperature higher than 900 °F (482 °C) for any period of time or over 600 °F (316 °C) for more than 1 hour.
Pipe size | No. of tests |
Less than 65/8 in (168 mm) nominal outside diameter | One test for each 200 lengths. |
65/8 in through 123/4 in (168 mm through 324 mm) nominal outside diameter | One test for each 100 lengths. |
Larger than 123/4 in (324 mm) nominal outside diameter | One test for each 50 lengths. |
Specification | Pipe class | Seam joint factor |
ASTM A53/A53M | Seamless | 1.00 |
Electric resistance welded | 1.00 | |
Furnace lap welded | 0.80 | |
Furnace butt welded | 0.60 | |
ASTM A106/A106M | Seamless | 1.00 |
ASTM A333/A333M | Seamless | 1.00 |
Welded | 1.00 | |
ASTM A381 | Double submerged arc welded | 1.00 |
ASTM A671/A671M | Electric-fusion-welded | 1.00 |
ASTM A672/A672M | Electric-fusion-welded | 1.00 |
ASTM A691/A691M | Electric-fusion-welded | 1.00 |
API Spec 5L | Seamless | 1.00 |
Electric resistance welded | 1.00 | |
Electric flash welded | 1.00 | |
Submerged arc welded | 1.00 | |
Furnace lap welded | 0.80 | |
Furnace butt welded | 0.60 |
49 C.F.R. §195.106