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

LTA Identifier

Enter a unique identifier for the LTA to be added to the list. This field is used to distinguish individual LTAs from each other.

Axial Extent of Flaw

Enter the length of the LTA in the axial (longitudinal) direction. 

Circumferential Extent of Flaw

Enter the width of the LTA in the circumferential direction.

Minimum Remaining Thickness

Enter the lowest remaining wall thickness within the LTA determined at the time of assessment.

Distance from Axial Datum to Center of Flaw

Enter the distance in the axial (longitudinal) direction from the axial datum to the center of the LTA. The axial datum can be any reference plane selected by the user; all LTAs must reference the same datum.

Distance from Circumferential Datum to Center of Flaw

Enter the distance in the circumferential direction from the circumferential datum to the center of the LTA. The circumferential datum can be any reference plane selected by the user; all LTAs must reference the same datum.

Distance to Nearest Structural Discontinuity

Enter the minimum distance from the nearest edge of the LTA to the nearest weld of a structural discontinuity. Examples of structural discontinuities include: vessel saddles/supports, nozzles, piping/platform supports, stiffening rings, conical transitions. This input will appear only for API-579 assessments.

Groove Checkbox

If the flaw can be classified as a groove this box should be checked. API-579 defines a groove as a "local elongated thin spot caused by directional erosion or corrosion; the length of the metal loss is significantly greater than the width." This option will not be available for B31G assessments as the B31G code does not support assessment of grooves; if grooves are present, API-579 should be selected under Analysis Code on the Vessel Data page.

Groove Radius

Enter the radius at the base of the groove. This input will only appear if the Groove Checkbox is checked.

Distance Between LTA Bottom and Tank Bottom, Hf

Enter the distance between the bottom of the tank and the nearest edge of the LTA. This input will only appear for tanks.

Add New

Click to add a new LTA to the list based on the inputs above.

Update

Click to save updates to a selected LTA based on the inputs above.

Delete

Click to delete a selected LTA.

Clear

Click to clear all input fields above.

Next

Click to compute and view results.