Calculate stress intensification factors (SIFs) for intersections using JPI
JPI provides two separate equations to calculate the in-plane and out-plane SIFs for intersections.
Calculate expansion stress using JPI
JPI provides an equation to calculate the expansion stress. However, this equation does not include calculations for the longitudinal stress due to axial loads in the pipe. CAESAR II does not include the F/A longitudinal stress component for stress in the expansion stress equation. The program adds the F/A longitudinal stress component, by default, to the code stress component for all other stress categories.
JPI girth butt welds default value
The default SIF value for a girth butt weld is 1.0. This is also Markl’s original basis for SIFs.
Calculate socket welds using JPI
JPI makes no distinction between socket welds with undercut and socket welds without undercut. Unless you are specifying a fillet weld leg length, use a default SIF value of 1.3.
Calculate the JPI Stress allowables
Expansion Allowable |
= |
f [ (1.25/Eff)(Sc+Sh) - Sl ] |
Sustained Allowable |
= |
Sh/Eff |
Occasional Allowable |
= |
(Occ)*Sh/Eff |
Where:
f = Cyclic Reduction Factor
Eff = Weld Joint Efficiency minimum wall thickness only
Sc = Ambient (cold) Allowable Stress, the minimum of 0.66Syc or 0.33Suc
Sh = Hot Allowable Stress, the minimum of 0.66Sy or 0.33Su
SI = Sustained Stress
Occ = Occasional Load Factor Default - 1.33
When specifying a corrosion allowance, do not use a corrosion value in the sustained and occasional stress calculations.
JPl reducer default value
The default SIF value is 1.0. The default Flexibility Factor value is 1.0.
Pressure effects and JPl
Pressure effects on miters are allowed in this piping code.
Seismic Analysis
JPI uses load cases defined by KHK.