Please see attached a slightly modified file.

How can be explained this?

LOAD CASE DEFINITION KEY

CASE 2 (SUS) W+P1
CASE 5 (SUS) L5=L1-L3


Piping Code: B31.3 = B31.3 -2006, May 31, 2007


CODE STRESS CHECK PASSED : LOADCASE 2 (SUS) W+P1

Highest Stresses: (lb./sq.in.) LOADCASE 2 (SUS) W+P1
CodeStress Ratio (%): 48.8 @Node 120
Code Stress: 5272.7 Allowable: 10800.0
Axial Stress: 933.0 @Node 128
Bending Stress: 4339.7 @Node 120
Torsion Stress: 40.7 @Node 109
Hoop Stress: 1920.0 @Node 20
3D Max Intensity: 5272.7 @Node 120

CODE STRESS CHECK FAILED : LOADCASE 5 (SUS) L5=L1-L3

Highest Stresses: (lb./sq.in.) LOADCASE 5 (SUS) L5=L1-L3
CodeStress Ratio (%): 109.7 @Node 69
Code Stress: 11846.7 Allowable: 10800.0
Axial Stress: 924.8 @Node 98
Bending Stress: 11006.0 @Node 69
Torsion Stress: 2030.5 @Node 80
Hoop Stress: 1920.0 @Node 20
3D Max Intensity: 12131.3 @Node 69


LISTING OF STATIC LOAD CASES FOR THIS ANALYSIS

1 (OPE) W+T1+P1
2 (SUS) W+P1
3 (EXP) T1
4 (EXP) L4=L1-L2
5 (SUS) L5=L1-L3


3D Max Intensity: 12131.3 @Node 69


Best regards,