PSI - Issue 3

6

J.L. González et al. / Procedia Structural Integrity 3 (2017) 48–56 Author name / Structural Integrity Procedia 00 (2017) 000–000

53

It should be remarked that the allowable stress S should be taken as the reduced tensile strength at the service temperature divided by a safety factor of 3.0, which for this case is 6.67 ksi. Substituting values:

34.72 142" 6670 0.6 34.72 psi x psi x 

 0.744'' 1

t





psi

Thus, the average measured thickness of the damaged ring is enough to withstand the internal pressure.

REGENERATOR UPPER BODY ORTOGONALLY STIFFENED RING A516 Gr.70, 1” THICKNESS

3

1 2

4

5

6

12

8 9 10 11

Existing ring

L r = 900 mm

Ring 1

Lr = 1000

Ring 2

Lr = 900 mm

Ring 3

Tripping bracket

REGENERATOR LOWER BODY

Fig. 4. Conceptual design of an orthogonally stiffened ring as reinforcement of the damaged section of the reactor striper.

4. Reinforcement calculation results Sections 4.4 and 5.5 of the API BULL 2U state that the buckling strength F xeL of the unrepaired section should be calculated first. The length of the reinforcement is 3302 mm (130”), which corresponds to the maximum separation of the stiffening rings. The formulas are:

(2)

113"/ 142" 1" x M x   9.48

0.4 9.0 / (300 284"/ 1") 

(3)

 0.704

xL  

0.5

150

 

  

  

  

2

4

65.2

(4)

1   

0.704 9.48 x

C



xL

284"/ 1"

2

2900

ksi



2

134ksi

65.2

(1"/ 113")

F

(5)





xeL

2

12(1 0.3 ) 

1/ 4



  

  

20 1.0 134 1.0 3.75(20 / 134 ) ksi ksi ksi ksi      

0.146

(6)







2