Page 265 - Pipelines and Risers
P. 265
238 Chapter 14
Q = Spiral correction factor
y = Factor of Safety.
The predicted bursting pressure level Pb is
Pb = rp (14.20)
Maximum Allowable Defect Adength
The Maximum Allowable Design Pressure P is
2t
P = F-SMYS (14.21)
D
Equating the Safe Maximum Pressure Level P to the Maximum Allowable Design Pressure:
(14.22)
The Maximum Allowable Effective Area AREAallow :
SMYS
Fv-
(14.23)
(Jflow
in which is the safety factor used in the new criterion.
The Maximum Allowable Length Lallow is
For Mallow 2 4.9
and for Mallow > 4.9
Lallow =J(Mallow- 3.3)/ 0.032fi (14.24)
where Mallow is solved by equating the Safe Maximum Pressure to the Maximum Allowable
Design Pressure as:
SMYS
R-
(14.25)
