APPENDIX D - CORROSION RATE and REMAINING LIFE CALCULATION

APPENDIX E CORROSION RATE and REMAINING LIFE CALCULATION

PT. REKAYASA SOLVERINDO

Page 1 of 5

CALCULATION SHEET Modul

: Corrosion Rate and Remaining Life Calculation

Equipment Identification           

: OFFSHORE GAS PIPELINE

Equipment Type                      

: 14" PIPELINE FROM KE‐5CPP TO ORF AT RISER SEGMENT KE‐5CPP (14‐CPP‐ORF‐01) Straight Pipe Area

Method

:

X Thickness Test

Corrosion Model

Other

DATA INPUT Variabel Material Year of Construction Year of Inspection Outside Diameter Original Thickness Current Thickness Minimum Required Thickness Current Corrosion Allowance

Symbol ‐ YC YI OD t ti tmin CAi

Unit ‐ ‐ ‐ mm mm mm mm mm

Value API 5L X46 1991 2008 355.6 12.7 12.4 9.89 2.51

Variabel Corrosion Rate Remaining Life

Symbol CR RL

Unit mm/year year

Comment

RESULT Value 0.02 >20

Comment

NOTES Remaining life calculation assumed: (a)  constant corrosion rate in pipelines (b) only for general/uniform corrosion Formulae: l Corrosion Rate = (t‐ti)/(YI‐‐YC) t

CA0

Remaining Life  =   CAi/CR

CAi tmin

ti

      t = original thickness       tmin = minimum required thickness       ti = current thickness       CA0 = original corrosion allowance       CAi = current corrosion allowance

Prepared by,  Form:  RS‐CS/CR‐RL/003

Checked by, 

Approved by,

PT. REKAYASA SOLVERINDO

Page 2 of 5

CALCULATION SHEET Modul

: Corrosion Rate and Remaining Life Calculation

Equipment Identification           

: ONSHORE UNDERGROUND GAS PIPELINE

Equipment Type                      

: 10" PIPELINE FROM ORF TO PJB AT ABOVEGROUND SEGMENT IN GAS PLANT (10‐0RF‐PJB‐01) Elbow Area

Method

:

X Thickness Test

Corrosion Model

Other

DATA INPUT Variabel Material Year of Construction Year of Inspection Outside Diameter Original Thickness Current Thickness Minimum Required Thickness Current Corrosion Allowance

Symbol ‐ YC YI OD t ti tmin CAi

Unit ‐ ‐ ‐ mm mm mm mm mm

Value API 5L X46 1991 2008 269.875 9.5 9.1 8.04 1.06

Variabel Corrosion Rate Remaining Life

Symbol CR RL

Unit mm/year year

Comment

RESULT Value 0.025 >20

Comment

NOTES Remaining life calculation assumed: (a)  constant corrosion rate in pipelines (b) only for general/uniform corrosion Formulae: l Corrosion Rate = (t‐ti)/(YI‐‐YC) t

CA0

Remaining Life  =   CAi/CR

CAi tmin

ti

      t = original thickness       tmin = minimum required thickness       ti = current thickness       CA0 = original corrosion allowance       CAi = current corrosion allowance

Prepared by,  Form:  RS‐CS/CR‐RL/003

Checked by, 

Approved by,

PT. REKAYASA SOLVERINDO

Page 3 of 5

CALCULATION SHEET Modul

: Corrosion Rate and Remaining Life Calculation

Equipment Identification           

: ONSHORE ABOVEGROUND OIL PIPELINE

Equipment Type                      

: 4" PIPELINE FROM ORF TO SG JETTY (4‐ORF‐SGJ‐01) Straight Pipe and Elbow Area

Method

:

X Thickness Test

Corrosion Model

Other

DATA INPUT Variabel Material Year of Construction Year of Inspection Outside Diameter Original Thickness Current Thickness Minimum Required Thickness Current Corrosion Allowance

Symbol ‐ YC YI OD t ti tmin CAi

Unit ‐ ‐ ‐ mm mm mm mm mm

Value API 5L Gr B 1991 2008 101.6 6.0 5.7 3.02 2.68

Variabel Corrosion Rate Remaining Life

Symbol CR RL

Unit mm/year year

Comment

RESULT Value 0.02 >20

Comment

NOTES Remaining life calculation assumed: (a)  constant corrosion rate in pipelines (b) only for general/uniform corrosion Formulae: Corrosion Rate = (t‐t C i R t (t ti)/(YI‐‐YYC) t

CA0

Remaining Life  =   CAi/CR

CAi tmin

ti

      t = original thickness       tmin = minimum required thickness       ti = current thickness       CA0 = original corrosion allowance       CAi = current corrosion allowance

Prepared by,  Form:  RS‐CS/CR‐RL/003

Checked by, 

Approved by,

PT. REKAYASA SOLVERINDO

Page 4 of 5

CALCULATION SHEET Modul

: Corrosion Rate and Remaining Life Calculation

Equipment Identification           

: OFFSHORE GAS PIPELINE

Equipment Type                      

: 12" PIPELINE FROM BW TO AW AT AW RISER SEGMENT (12‐BW‐AW‐03) Straight Pipe Area

Method

:

X Thickness Test

Corrosion Model

Other

DATA INPUT Variabel Material Year of Construction Year of Inspection Outside Diameter Original Thickness Current Thickness Minimum Required Thickness Current Corrosion Allowance

Symbol ‐ YC YI OD t ti tmin CAi

Unit ‐ ‐ ‐ mm mm mm mm mm

Value API 5L X46 1977 2008 304.80 17.5 16.9 2.94 13.96

Variabel Corrosion Rate Remaining Life

Symbol CR RL

Unit mm/year year

Comment

RESULT Value 0.02 >20

Comment

NOTES Remaining life calculation assumed: (a)  constant corrosion rate in pipelines (b) only for general/uniform corrosion Formulae: l Corrosion Rate = (t‐ti)/(YI‐‐YC) t

CA0

Remaining Life  =   CAi/CR

CAi tmin

ti

      t = original thickness       tmin = minimum required thickness       ti = current thickness       CA0 = original corrosion allowance       CAi = current corrosion allowance

Prepared by,  Form:  RS‐CS/CR‐RL/003

Checked by, 

Approved by,

PT. REKAYASA SOLVERINDO

Page 5 of 5

CALCULATION SHEET Modul

: Corrosion Rate and Remaining Life Calculation

Equipment Identification           

: OFFSHORE OIL PIPELINE

Equipment Type                      

: 8" PIPELINE FROM AW TO KE‐5CPP AT KE‐5CPP RISER SEGMENT (8‐AW‐CPP‐03) Straight Pipe Area

Method

:

X Thickness Test

Corrosion Model

Other

DATA INPUT Variabel Material Year of Construction Year of Inspection Outside Diameter Original Thickness Current Thickness Minimum Required Thickness Current Corrosion Allowance

Symbol ‐ YC YI OD t ti tmin CAi

Unit ‐ ‐ ‐ mm mm mm mm mm

Value API 5L X46 1998 2008 219.08 12.7 12.5 7.07 5.43

Variabel Corrosion Rate Remaining Life

Symbol CR RL

Unit mm/year year

Comment 

RESULT Value 0.02 >20

Comment 

NOTES Remaining life calculation assumed: (a)  constant corrosion rate in pipelines (b) only for general/uniform corrosion FFormulae: l Corrosion Rate = (t‐ti)/(YI‐‐YC) t

CA0

Remaining Life  =   CAi/CR

CAi tmin

ti

      t = original thickness       tmin = minimum required thickness       ti = current thickness       CA0 = original corrosion allowance       CAi = current corrosion allowance

Prepared by,  Form:  RS‐CS/CR‐RL/003

Checked by, 

Approved by,