Pipeline Crack Defect Modules

Calculate AGA NG-18 Level 0 critical defect length and minimum required fracture toughness from flow stress and hoop stress.

The level 0 assessment is useful as a screening check for crack defects. The level 0 check is from AS 2885.1. The temperature derating calculation is from ASME B31.8. Material specific test data should be used if it is available. Use the level 1 assessment for simple defects from defect length and depth. Use the level 2 assessment for complex defects from the defect river bottom profile. Refer to the module list below.

AGA NG-18 is suitable for crack defects. For blunt defects including corrosion, mechanical damage and grinding repairs etc the ASME B31G or RSTRENG calculators are recommended.

Reference : AGA Pipeline Research Committee NG-18 Report 204 Ductile Fracture Properties of Selected Linepipe Steels

Change Module :

• AGA NG18 Flow Stress Calculation Module
• AGA NG18 Level 1 Defect Assessment Calculation Module
• AGA NG18 Level 2 Defect Assessment Calculation Module
• All

Related Modules :

• ASME B31G Pipe Corrosion Defect Calculation Module
• DNVGL RP F101 Corrosion Line Pipe Schedule Calculation Module
• PRCI PR 3805 RSTRENG Calculation Module
• More Corrosion Modules

Calculate AGA NG-18 level 2 crack defect assessment.

The level 2 assessment calculates the allowable pressure from the defect "river bottom" profile using the effective area method (also known as the RSTRENG method). Pressure derating is required if the allowable pressure is less than the maximum operating pressure.

The flow stress can be calculated as either 1.1 x SMYS, SMYS + 69 MPa, or 1/2 (SMYS + SMTS). For pipelines operating at high temperature, the SMYS and SMTS should be derated.

For submerged pipelines, or to calculate the allowable pressure at a reference elevation, use the level 1 and level 2 calculators including elevation. The allowable local pressure is calculated including external pressure (use the external pressure = 0 for dry pipelines). The allowable reference pressure is calculated from the local allowable pressure, and the relative elevation.

AGA NG-18 is suitable for crack defects. For blunt defects including corrosion, mechanical damage and grinding repairs etc the ASME B31G or RSTRENG calculators are recommended.

Reference : AGA Pipeline Research Committee NG-18 Report 204 Ductile Fracture Properties of Selected Linepipe Steels

Change Module :

• AGA NG18 Crack Defect Calculation Module
• AGA NG18 Flow Stress Calculation Module
• AGA NG18 Level 1 Defect Assessment Calculation Module
• All

Related Modules :

• ASME B31G Pipe Corrosion Defect Calculation Module
• DNVGL RP F101 Corrosion Line Pipe Schedule Calculation Module
• PRCI PR 3805 RSTRENG Calculation Module
• More Corrosion Modules