All inputs that appear in this input section are required unless otherwise specified.

Assessment Level

Select the assessment Level.

Assessment Parameter

Select whether to use thickness (tmin) or pressure/fill height (MAWP/MFH) as the basis for the assessment. This selection determines the acceptance criteria to be used in the assessment per API 579 Part 4 Tables 4.4 – 4.7. Additional inputs will be required to calculate the MAWP/MFH and tmin for Level 2 assessments or if the MAWP/MFH option is selected for Level 1 assessments (See MAWP/MFH Calculator). If Thickness Basis is selected for a Level 1 assessment the user is responsible for determining the minimum required thickness.

Component Geometry

Select geometry based on the type and shape of the component.

Damaged region is in the center section of the head

Check this box if the local metal loss is located within the center portion of the head. For elliptical heads this is a section within 0.8D centered on the head centerline. For torispherical heads this is the section in the spherical portion of the head, beyond the knuckle radius. This input will appear only for elliptical and torispherical head geometries.

Elliptical Head Ratio, Rell

Enter the elliptical head ratio, i.e. the ratio of the major to minor axis of an elliptical head. This input will appear only for elliptical heads.

Crown Radius, Cr

Enter the inside radius of the spherical portion of the torispherical head. This input will appear only for torispherical heads.

Corrosion Location

Select whether corrosion is located on the inside or outside. The assessment is not valid when corrosion is present on both the inside and outside diameter.

Component Minimum Required Thickness, tmin

Enter the minimum required thickness for the component per the requirements of the original code of construction.

Longitudinal Minimum Required Thickness, tLmin

Enter the minimum required thickness for the component based on longitudinal stresses per the requirements of the original code of construction.

Circumferential Minimum Required Thickness, tCmin

Enter the minimum required thickness for the component based on circumferential or hoop stresses per the requirements of the original code of construction.

Nominal Thickness, tnom

Enter the original component thickness in requested units.

Prior Uniform Metal Loss Remote from Damaged Region, LOSS

Enter the amount of uniform metal loss away from the local metal loss location at the time of the assessment.

Nominal Inside Diameter

Enter the original inside diameter of the component in requested units.

Future Corrosion Allowance Away from Metal Loss, FCA

Enter the allowable future corrosion in the component away from the localized thinning.

Future Corrosion Allowance Local to Metal Loss, FCAml

Enter the allowable future corrosion in the component in the area of localized thinning.

Allowable Remaining Strength Factor, RSFa

Enter the allowable remaining strength factor for the component. The recommended value for RSFa per API-579 Part 2 paragraph 2.4.2.2.d is 0.9. Refer to API-579 Annex 2F for guidance on establishing alternative values for RSFa.

Next

Click to proceed to the Data Input Screen