Modified CSA Z662 ACCeptAbility CriteriA

Criterion number

Criterion description Notes

Corrosion / Metal loss

1 Corrosion metal loss depth ≥75% of the nominal wall thickness.

2 Corrosion metal loss with a depth <75% and >10% of nominal wall thickness and a predicted burst pressure <139% of Mop based on Modified b31G method.

3 Corrosion metal loss with a depth <75% and >10% of nominal wall thickness predicted to grow to a depth ≥75% of the nominal wall thickness and/or a size corresponding with a predicted burst pressure <139% of Mop based on Modified b31G method within three years.

4 for those lines known to be susceptible to internal corrosion, at the discretion of the integrity specialist, additional criteria may be adopted which can take into consideration whether the features will grow to a depth of 75% of the pipe wall thickness within three years.

Segment assumed to be not susceptible to internal corrosion based on products being transported and tNpi experience.

deformation

5 Any dent/ovality with a stress concentrator (gouge, groove, arc burn, or crack) or metal loss1.

6 Any dent/ovality ≥6% of the od for pipe with an od >101.6 mm.

7 dents within one diameter of another dent.

8 topside dents (or unconstrained bottomside dents) with a depth ≥3% and <6% (pipe body).

9 topside dents (or unconstrained bottomside dents) with a depth <3% and ≥2% (pipe body).

10 topside dents (or unconstrained bottomside dents) with depth ≥0.5% od but <2% od (pipe body). these features are subject to an engineering analysis.

11 Any dents with predicted remaining life <10 years. this criterion is only applied for dents subject to the engineering analysis from criterion 10.

12 Any dents with a calculated strain >6%. this criterion is only applied for dents subject to the engineering analysis from criterion 10.

13 dent on a mill or field weld:2 ≥0.5% od but <2% od deep for pipe with an od >323.9 mm or <6mm for pipe with an od ≤323.9mm.

these features are subject to an engineering analysis.

14 dent on a mill or field weld:2 ≥2% of the od for pipe with an od >323.9 mm or a depth ≥6mm for pipe with an od ≤323.9mm.

15 Wrinkles with a maximum vertical height of any wave, measured from the average height of two adjoining crests to the valley, >3% od, a wavelength to height ratio ≤ 12, or a circumferential extent ≥120° of the pipe’s circumference.

this criterion can only be applied based on field observations and not ili results.

Modified CSA Z662 ACCeptAbility CriteriA

Criterion number

Criterion description Notes

Cracks3, 6

16 Crack-field and crack-like features (including surface-breaking laminations) with predicted depth ≥40% of the nominal wall thickness (include notch-like and weld anomalies if their depths are reported).

17 Crack-field, crack-like, notch-like, and weld anomaly features (including surface-breaking laminations) with a predicted burst pressure <139% of Mop4.

18 preferential seam weld corrosion > 40% of the nominal wall thickness or assessed as a crack with a predicted burst pressure <139% Mop.

19 Crack-field and crack-like features (including surface-breaking laminations) located in a dent (include notch-like and weld anomalies if their depths are reported).

20 Crack-field and crack-like features (including surface-breaking laminations) predicted to grow to a depth ≥40% of the nominal wall thickness or a size corresponding to a predicted burst pressure <139% Mop4 within three years (include notch-like and weld anomalies if their depths are reported).

21 laminations which run into either the longitudinal weld or girth weld5.

22 laminations determined to be blisters. this criterion can only be applied based on field observations and not ili results.

23 Corrosion metal loss containing cracks.

other

24 Gouges, grooves, and arc burns. None identified in the inspection data.

25 Any weld containing an imperfection that fails an engineering assessment. this criterion can only be applied based on field observations and not ili results.

26 Any other condition which, in the opinion of the ili specialist, requires remediation. Case by case.

1 to meet criteria, metal loss, cracking or stress risers must be interacting with a dent. interaction is defined as any metal loss, cracking or stress riser that overlaps with a dent after the tool tolerance (length and width) has been applied to both the stress riser and the dent. this method identifies both axial and circumferential interaction.

2 dents must be within +/–50 mm of a girth weld or +/–50 mm of a longseam weld.3 preferential seam weld corrosion shall be assessed as a crack.4 the length of crack-field and crack-like feature(s) to be used in the critical flaw calculations shall

be the “maximum interlinked crack length” reported by the in-line inspection vendor, if provided, otherwise it shall be the “total length of the crack.

5 the laminations/inclusions reported near (within 25 mm of) longitudinal seam weld and girth welds.