PL Risk Based Assessment Appendix 1. MAT Override

Take Note

This overview will explain the MAT Override functionality in the IMS PLSS RBA module.

For each row in the Corrosion tolerance grid (left upper pane) the application calculates the MAT and the corrosion tolerance. However, it is possible to specify a MAT Override. If MAT Override is greater than the calculated MAT, then MAT Override is used to calculate the remaining corrosion tolerance.

In the example below the MAT Override is 3.5 mm.

In the Internal Corrosion grid on:

• row 1 the MAT Override is less than the MAT Int Morph (3.61 mm), CT Int Morph is used to calculate the CT Remain

• row 2 the MAT Override is less than the MAT Defect (3.86 mm), CT Defect is used to calculate the CT Remain

• row 3 the MAT Override is greater than the MAT Defect (3.32 mm), CT Override is used to calculate the CT remaining

In graphical form:

Row 3

Row 2

Row 1

The MAT Override is based on pipeline characteristics:

• Diameter

• Material grade

• ILI completed

The MAT Override should be specified in the MAT Override table that can be found under Settings / Maintenance /  PLSS Specific Data / Pipe Data / MAT override.

In the first two columns the user can specify the diameter. Note that the maximum diameter is not part of the check.

Example: If the MAT override should be 1.5 mm for diameters till 10”, including the 10” for all material grades and whether ILI has been completed or not then the following parameters should be filled in: