B31G Calculator

Disclaimer and Legal Notice This Excel-based calculator was prepared by Clock Spring Company L.P. based on the equations and work sponsored by Gas Technology Institute (GTI) and reported in GRI 98/0265 "Pipeline Repair Assessment Software Tool - GRIWrap for Windows and GRI 95/0244 "GRIWrap Pipeline Repair Program". The B31 Calculator is based on ASME B31G-1991, "Manual for Determining the Remaining Strength of Corroded Pipelines.

Legal Notice Neither Clock Spring Company L.P. nor GTI, nor any person acting on behalf of them: A. Makes any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or that the use of any method or process disclosed may not infringe privately owned rights; or B. Assumes any liability with respect to the use of or for damages resulting from the use of, any information, apparatus, method, calculation, or process in this work.

Clock Spring Company L.P. 14107 Interdrive West, Houston, Texas, 77032 Phone 281-590-8491 Fax. 281-590-9528 www.clockspring.com Version 120302

Data Input 24.000

inches

Wall Thickness (t) Pipe Strength (SMYS) Defect Depth

0.375 52000 0.18

inches psi inches

2 488 0.72 1 1

inches psi

Clock Spring is acceptable, Shape Factor = 1 Output Messages Defect depth % of wall 48.0% UTS (Approximate) 66000

psi

Design Pressure (MAOP or P) Safe Operating Pressure (P')

psi psi

1170 1170

0.35

Column U

0.3

Column G

Column L

0.25 0.2 0.15 0.1 0.05 0

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 22.5 23 23.5 24 24.5 25 25.5 26 26.5 27 27.5 28 28.5 29 29.5 30 30.5 31 31.5 32 32.5 33 33.5 34 34.5 35 35.5 36 36.5 37 37.5

Defect Length Operating Pressure (MOP) Design Factor (DF) Temperature Factor (TF) Pipe Joint Factor (JF)

Allowable Defect Depth vs. Length (at Design and Operating Pressures)

Depth (inches)

Pipe Diameter (Dia.)

Length (inches)

Clock Spring is acceptable, Shape Factor = 1 Maximum defect length and depth from B31G. With corrosion length of 2 inches, and MOP of With corrosion depth of 0.18 inches, and MOP of No repair needed.

488 psi max depth is 488 psi max length is

0.300 inches. NL inches.

Calculations from GRIWrap Analysis. Pressure-failure reinforced (Pfr)

2271 psi

Shape factor (B)

1

Pressure-pristine yield (Pyo)

1625 psi

Ratio Pfr / Pyo

1.40

279127992.xls

Engineering Analysis - Clock Spring® Pipe Details Outside diameter (Dia.) Wall thickness (t) Grade (SMYS)

Operating Details

24.00 inches 0.375 inches 52000 psi

Operating pressure (Po) 488 psi Class Location 1 Design Factor 0.72 Temp.Factor (TF) 1 Joint Factor (JF) 1

Defect Details Defect depth Defect length Depth as % of wall

0.180 inches 2.00 inches 48%

Defect identification Date

August 11, 2015

B31G Assessment Maximum allowable pressure (P) (MAOP) Safe operating pressure (Ps)

1170 psi 1170 psi

P = ((2*SMYS*t)/Dia.)*DF*TF*JF

At the operating pressure (Po) specified the maximum length for the depth specified is not limitted. At the operating pressure (Po) specified the maximum depth for the length specified is 0.300 inches

The pipeline is operating safely.

Clock Spring® Analysis Pristine yield pressure of the pipe. Failure pressure of the reinforced pipe. Reinforced failure to pristine yield ratio. Defect profile factor.

1625 psi 2271 psi 1.40 1

-

Pyo Prf

Pyo = (2*SMYS*t)/Dia.

Clock Spring® repair is acceptable. Values used in calculation. Failure stress of the Clock Spring® - 20 ksi

Clock Spring® Analysis

Modulus of the Clock Spring® - 5 x106 psi Modulus of the pipe - 30 x106 psi

2500

Wrap thickness - 0.0625 inches.

2000

Number of wraps - 8 Thickness of repair - 0.5 inches.

1500

Defect circumferential extent - 100%

1000 500 0 Po

Prf

Pyo

P (MAOP)

Ps

279127992.xls

Po Prf Pyo P Ps -

Operating pressure. Reinforced failure pressure. Pristine yield pressure. Design pressure (MAOP) Safe operating pressure (B31G). Version 120302