16.6 Determination of the Damage Factor 16.6.1 Overview
16.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting the specific damage mechanism.
Examples of inspection activities that are both intrusive (requires entry into the equipment) and non-intrusive (can be performed externally), are provided in Annex 2.C, Table 7.17.
16.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting external corrosion and correctly predicting the rate of damage.
Examples of inspection activities for external corrosion are provided in Table 16.2.
The effectiveness of each inspection performed within the designated time period must be characterized in accordance with Table 16.2. The number and category of the highest effective inspection will be used to determine the damage factor. If multiple inspections of a lower effectiveness have been conducted during the designated time period, they can be equated to an equivalent higher effectiveness inspection in accordance with paragraph 4.4.3.
16.6.3 Calculation of the Damage Factor
16.7 Nomenclature
16.8 Tables
Table 16.2 – Guidelines for Assigning Inspection Effectiveness – External Corrosion
Inspection Category
Inspection Effectiveness
Category
Inspection
A Highly Effective
Visual inspection of >95% of the exposed surface area with follow-up by UT, RT or pit gauge as required.
B Usually Effective
Visual inspection of >60% of the exposed surface area with follow-up by UT, RT or pit gauge as required.
C Fairly Effective Visual inspection of >30% of the exposed surface area with follow-up by UT, RT or pit gauge as required.
D Poorly Effective
Visual inspection of >5% of the exposed surface area with follow-up by UT, RT or pit gauge as required.
E Ineffective Visual inspection of <5% of the exposed surface area with follow-up by UT, RT or pit gauge as required.
17 CUI DAMAGE FACTOR – FERRITIC COMPONENT
17.1 Scope
17.2 Description of Damage
17.3 Screening Criteria
17.4 Required Data
17.5 Basic Assumption
17.6 Determination of the Damage Factor 17.6.1 Overview
17.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting the specific damage mechanism.
Examples of inspection activities that are both intrusive (requires entry into the equipment) and non-intrusive (can be performed externally), are provided in Annex 2.C, Table 7.18.
17.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting CUI and correctly predicting the rate of damage.
Examples of inspection activities for detection of CUI are provided in Table 17.2
The effectiveness of each inspection performed within the designated time period must be characterized in accordance with
.
Table 17.2. The number and category of the highest effective inspection will be used to determine the damage factor. If multiple inspections of a lower effectiveness have been conducted during the designated time period, they can be equated to an equivalent higher effectiveness inspection in accordance with paragraph 4.4.3
17.6.3 Calculation of the Damage Factor .
17.7 Nomenclature
17.8 Tables
Table 17.2 – Guidelines for Assigning Inspection Effectiveness – CUI
Inspection Category
Inspection Effectiveness
Category
INSULATION REMOVED Insulation Not Removed
A Highly Effective
For the total surface area:
100% visual inspection prior to removal of insulation
AND
Remove >95% of the insulation including suspect areas;
AND
For the total surface area:
100% visual inspection AND
100% inspection with highly effective NDE technique (such as profile or real-time radiography or guided wave UT)
100% visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
AND
strip 100% of areas where NDE technique is not effective (e.g., fittings)
AND
100% visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
or real-time radiography.
B Usually Effective
For the total surface area:
>95% external visual inspection prior to removal of insulation;
AND
remove >60% of total surface area of insulation including suspect areas;
AND
visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
For the total surface area:
>95% visual inspection AND
> 60% inspection with highly effective NDE technique (such as profile or real-time radiography or guided wave UT) including suspect areas
AND
strip > 60% of areas where NDE technique is not effective (e.g., fittings)
AND
100% visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
C Fairly Effective
For the total surface area:
>95% external visual inspection prior to removal of insulation;
AND
remove >30% of total surface area of insulation including suspect areas;
AND
visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
For the total surface area:
>95% visual inspection AND
> 24% inspection with highly effective NDE technique (such as profile or real-time radiography or guided wave UT) including suspect areas
AND
strip > 24% of areas where NDE technique is not effective (e.g., fittings)
AND
100% visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
D Poorly Effective
>95% external visual inspection prior to removal of insulation;
AND
remove >5% of total surface area of insulation including suspect areas.
AND
For the total surface area:
>95% visual inspection AND
> 5% inspection with highly effective NDE technique (such as profile or real-time radiography or guided wave UT) including suspect
visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
areas AND
strip > 5% of areas where NDE technique is not effective (e.g., fittings)
AND
100% visual inspection of the exposed surface area with follow-up by UT, RT or pit gauge as required.
E Ineffective
<5% insulation removal and inspection;
OR
no inspection or ineffective inspection technique.
No inspection or ineffective inspection technique or <95% visual inspection.
18 EXTERNAL CLSCC DAMAGE FACTOR – AUSTENITIC COMPONENT
18.1 Scope
18.2 Description of Damage
18.3 Required Data
18.4 Basic Assumption
18.5 Determination of the Damage Factor 18.5.1 Overview
18.5.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting the specific damage mechanism.
Examples of inspection activities that are both intrusive (requires entry into the equipment) and non-intrusive (can be performed externally), are provided in Annex 2.C, Table 7.19.
18.5.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting external CLSCC and correctly predicting the rate of damage.
Examples of inspection activities for detection of external CLSCC are provided in Table 18.2
The effectiveness of each inspection performed within the designated time period must be characterized in accordance with
.
Table 18.2. The number and category of the highest effective inspection will be used to determine the damage factor. If multiple inspections of a lower effectiveness have been conducted during the designated time period, they can be equated to an equivalent higher effectiveness inspection in accordance with paragraph 4.4.3
18.5.3 Calculation of the Damage Factor .
18.6 Nomenclature
18.7 Tables
Table 18.2 – Guidelines for Assigning Inspection Effectiveness – External CLSCC
Inspection Category
Inspection Effectiveness
Category
Inspection
A Highly Effective
For the total surface area: greater than 95% dye penetrant or eddy current test with UT follow-up of relevant indications.
B Usually Effective
For the total surface area: greater than 60% dye penetrant or eddy current testing with UT follow-up of all relevant indications.
C Fairly Effective For the total surface area: greater than 30% dye penetrant or eddy current testing with UT follow-up of all relevant indications.
D Poorly Effective
For the total surface area: greater than 5% dye penetrant or eddy current testing with UT follow-up of all relevant indications.
E Ineffective Less than “D” effectiveness or no inspection or ineffective inspection
technique used.
19 EXTERNAL CUI CLSCC DAMAGE FACTOR – AUSTENITIC COMPONENT
19.1 Scope
19.2 Description of Damage
19.3 Screening Criteria
19.4 Required Data
19.5 Basic Assumption
19.6 Determination of the Damage Factor 19.6.1 Overview
19.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting the specific damage mechanism.
Examples of inspection activities that are both intrusive (requires entry into the equipment) and non-intrusive (can be performed externally), are provided in Annex 2.C, Table 7.20.
19.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting external CUI CLSCC and correctly predicting the rate of damage.
Examples of inspection activities for detection of external CUI CLSCC are provided in Table 19.2
The effectiveness of each inspection performed within the designated time period must be characterized in accordance with
.
Table 19.2 The number and category of the highest effective inspection will be used to determine the damage factor. If multiple inspections of a lower effectiveness have been conducted during the designated time period, they can be equated to an equivalent higher effectiveness inspection in accordance with paragraph 4.4.3
19.6.3 Calculation of the Damage Factor .
19.7 Nomenclature
19.8 Tables
Table 19.2 – Guidelines for Assigning Inspection Effectiveness – CUI CLSCC
Inspection Category
Inspection Effectiveness
Category
Insulation Removed Insulation Not Removed
A Highly Effective
For the total surface area: greater than 95% dye penetrant or eddy current test with UT follow-up of relevant indications.
No inspection techniques yet available meet requirements of "A".
B Usually Effective
For the total surface area: greater than 60% dye penetrant or eddy
For the total surface area:
Greater then 95% automated or
current testing with UT follow-up of all relevant indications.
manual ultrasonic scanning from the internal surface
OR
AE testing with 100% follow-up of relevant indications.
C Fairly Effective
For the total surface area: greater than 30% dye penetrant or eddy current testing with UT follow-up of all relevant indications.
For the total surface area:
Greater than 67% automated or manual ultrasonic scanning from the internal surface
D Poorly Effective
For the total surface area: greater than 5% dye penetrant or eddy current testing with UT follow-up of all relevant indications
For the total surface area:
Greater than 30% automated or manual ultrasonic scanning from the internal surface
OR
Greater than 60% radiographic testing.
E Ineffective
Less than “D” effectiveness or no inspection or ineffective inspection technique used
Less than “D” effectiveness or no inspection or ineffective inspection technique used
20 HTHA DAMAGE FACTOR
20.1 Scope
20.2 Description of Damage
20.3 Screening Criteria
20.4 Required Data
20.5 Basic Assumption
20.6 Determination of the Damage Factor 20.6.1 Overview
20.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting the specific damage mechanism.
Examples of inspection activities that are both intrusive (requires entry into the equipment) and non-intrusive (can be performed externally), are provided in Annex 2.C, Table 7.21.
20.6.2 Inspection Effectiveness
Inspections are ranked according to their expected effectiveness at detecting HTHA and correctly predicting the rate of damage.
Examples of inspection activities for detection of HTHA are provided in Table 20.2
The effectiveness of each inspection performed within the designated time period must be characterized in accordance with
.
Table 20.2. The number and category of the highest effective inspection will be used to determine the damage factor. If multiple inspections of a lower effectiveness have been conducted during the designated time period, they can be equated to an equivalent higher effectiveness inspection in accordance with paragraph 4.4.3
For HTHA, damage factors are only provided for two inspections. If more than two inspections are performed that conform to
.
Table 20.2
20.6.3 Calculation of the Damage Factor
Table 7.21, then the damage factor for two inspections shall be used.
20.7 Nomenclature
20.8 Tables
Table 20.2 – Guidelines for Assigning Inspection Effectiveness – HTHA
Inspection Category
Inspection Effectiveness
Category
Inspection
A Highly Effective
Inspection techniques for HTHA are not available to qualify for a category A inspection.
B Usually Effective
Extensive Advanced Ultrasonic Backscatter Technique (AUBT), spot AUBT based on stress analysis or extensive in-situ metallography.
C Fairly Effective Spot AUBT or spot in-situ metallography.
D Poorly Ultrasonic backscatter plus attenuation.
Effective
E Ineffective Attenuation only
21 BRITTLE FACTURE DAMAGE FACTOR
21.1 Scope
21.2 Description of Damage
21.3 Screening Criteria
21.4 Required Data
21.5 Basic Assumption
21.6 Determination of the Damage Factor 21.6.1 Overview
21.6.2 Inspection Effectiveness
Low temperature/low toughness fracture is prevented by a combination of appropriate design and operating procedures. When low temperature/low toughness fracture does occur, it almost invariably initiates at some pre-existing crack-like defect. From the initiation point, a crack will grow quickly, resulting in a serious leak or sometimes complete rupture of the component. Theoretically, an inspection to locate and remove such pre-existing defects would reduce the probability of failure. However, the initiating defect can be very small, and need not be exposed to the surface where it could be found. For this reason, inspection for such defects is generally not considered to be an effective method for prevention of brittle fracture.
If existing records of an component do not indicate if it is constructed of normalized plate, then a metallurgical examination may help resolve this. In some cases, it may be possible to remove samples of the material large enough for testing to determine the toughness, which can also improve the accuracy of the prediction of low temperature/low toughness fracture likelihood.
For this damage mechanism, credit is not given for inspection. However, the results of metallurgical testing can be used to update the inputs to the damage factor calculation that may result in a change in this value.
21.6.3 Calculation of the Damage Factor
21.7 Nomenclature
21.8 Tables
22 TEMPER EMBRITTLEMENT DAMAGE FACTOR
22.1 Scope
22.2 Description of Damage
22.3 Screening Criteria
22.4 Required Data
22.5 Basic Assumption
22.6 Determination of the Damage Factor 22.6.1 Overview
22.6.2 Inspection Effectiveness
For this damage mechanism, credit is not given for inspection.
22.6.3 Calculation of the Damage Factor
However, the results of metallurgical testing can be used to update the inputs to the damage factor calculation that may result in a change in this value.
22.7 Nomenclature
22.8 References
22.9 Tables
Formatted: Underline
23 885 EMBRITTLEMENT DAMAGE FACTOR
23.1 Scope
23.2 Description of Damage
23.3 Screening Criteria
23.4 Required Data
23.5 Basic Assumption
23.6 Determination of the Damage Factor 23.6.1 Overview
23.6.2 Inspection Effectiveness
For this damage mechanism, credit is not given for inspection.
23.6.3 Calculation of the Damage Factor
However, the results of metallurgical testing can be used to update the inputs to the damage factor calculation that may result in a change in this value.
23.7 Nomenclature
23.8 References
23.9 Tables
Formatted: Underline
24 SIGMA PHASE EMBRITTLEMENT DAMAGE FACTOR
24.1 Scope
24.2 Description of Damage
24.3 Screening Criteria
24.4 Required Data
24.5 Basic Assumption
24.6 Determination of the Damage Factor 24.6.1 Overview
24.6.2 Inspection Effectiveness
For this damage mechanism, credit is not given for inspection.
24.6.3 Calculation of the Damage Factor
However, the results of metallurgical testing can be used to update the inputs to the damage factor calculation that may result in a change in this value.
24.7 Nomenclature
24.8 References
24.9 Tables
Formatted: Underline
25 PIPING MECHANICAL FATIGUE DAMAGE FACTOR
25.1 Scope
25.2 Description of Damage
25.3 Screening Criteria
25.4 Required Data
25.5 Basic Assumption
25.6 Determination of the Damage Factor 25.6.1 Overview
25.6.2 Inspection Effectiveness For this damage mechanism
Mechanical fatigue failures in piping are not that common. Unfortunately, when failures occur, they can be of high consequence. In addition and more unfortunately, traditional non-destructive testing techniques are of little value in preventing such failures. The reason that crack detection techniques are not by themselves adequate are several.
, credit is not given for inspection. However, the results of metallurgical testing can be used to update the inputs to the damage factor calculation that may result in a change in this value.
a) Most of the time to failure in piping fatigue is in the initiation phase, where a crack in the process of forming has formed but is so small that it is undetectable.
b) By the time a crack has reached a detectable size, the crack growth rate is high, and failure will likely occur in less than a typical inspection frequency.
c) Cyclic stresses in vibrating piping tend to have a fairly high frequency, which increases the crack growth rate.
d) Cracks form and grow in locations that are typically difficult to inspect, such as at fillet weld toes, the first unengaged thread root and defects in other welds.
e) The initiation site for crack growth is not necessarily on the outside of the pipe; in fact, a crack can grow from an embedded defect undetectable from either side without special techniques.
Therefore, inspection for mechanical fatigue in piping systems depends heavily on detection and correction of the conditions that lead to susceptibility. Such techniques include:
a) Visual examination of pipe supports to assure that all supports are functioning properly (i.e., they are actually supporting the pipe).
b) Visual examination of any cyclic motion of the pipe. If pipe can be seen to be vibrating or moving in a cyclic manner, the pipe should be suspected of mechanical fatigue failure.
c) Visual examination of all fillet welded supports and attachments to piping. Fillet welds are especially susceptible to failure by fatigue, and these may provide an early warning of problems if cracks or failures are found.
d) As a general rule, small branch connections with unsupported valves or controllers on them are highly susceptible to failure. Examine these for signs of motion, and provide proper support for all such installations.
e) Surface inspection methods (PT, MT) can be effective in a focused and frequent inspection plan.
f) Manually feeling the pipe to detect vibration. This requires experience, but normally process plant piping will not vibrate any more severely than a car engine at idle speed.
Formatted: Underline
Formatted: Indent: Left: 0.25", Tab stops:
0.5", List tab + Not at 0.3"
Formatted: Indent: Left: 0.25", Tab stops:
0.5", List tab + Not at 0.3"
g) Measurement of piping vibration using special monitoring equipment. There are no set values of vibration that will be acceptable or non acceptable under all conditions, so experience with using and interpreting vibration data is required.
h) Visual inspection of a unit during transient conditions and different operating scenarios (e.g., startups, shutdowns, upsets, etc.) looking for intermittent vibrating conditions.
i) Checking for audible sounds of vibration emanating from piping components such as control valves and fittings.
25.6.3 Calculation of the Damage Factor
25.7 Nomenclature
25.8 Tables
ANNEX 2.C
(INFORMATIVE ANNEX)
LEVELS OF INSPECTION EFFECTIVENESS
PART CONTENTS
1 SCOPE ... 3 2 REFERENCES ... 3 3 DEFINITIONS ... 4 3.1 Definitions ... 4 3.2 Acronyms ... 5 4 INSPECTION EFFECTIVENESS ... 5 4.1 The Value of Inspection ... 5 4.2 Inspection Effectiveness Caclulation ... 6 4.3 Inspection Effectiveness Categories ... 7 4.4 Inspection Effectiveness – Example ... 7 4.5 Inspection Planning ... 8 4.6 Nomenclature ... 8 4.7 Tables... 9 Table 4.1 – Inspection Effectiveness Categories ... 9 4.8 Figures ... 10 5 PRESSURE RELIEF DEVICES ... 11 Table 5.1 – Inspection and Testing Effectiveness for Pressure Relief Devices ... 12 6 HEAT EXCHANGER TUBE BUNDLES ... 13 6.1 Inspection Planning with Inspection History ... 13 Table 6.1 – Inspection Effectiveness and Uncertainty ... 13 7 TANKS, NON-METALLIC LININGS, AND BURIED COMPONENTS ... 15 7.1 Inspection Effectiveness for Above GroundStorage Tanks ... 15 7.2 Inspection Effectiveness for Non-Metallic Linings ... 15 7.3 Inspection Effectiveness for Buried Components ... 15 Table 7.1 – LoIE Example for Tank Shell Course Internal Corrosion ... 16 Table 7.2 – LoIE Example for Tank Shell Course External Corrosion ... 17 Table 7.3 – LoIE Example for Tank Bottoms ... 18 Table 7.4 – LoIE Example for Corrosion Resistant Non-Metallic Liner ... 19 Table 7.5 – LoIE Example for Buried Components ... 20 8 INSPECTION EFFECTIVENESS TABLES FOR THINNING AND CRACKING ... 21 8.1 Use of the Inspection Effectiveness Tables... 21 8.2 Assumptions for the Effectiveness Tables ... 21 8.3 Levels of Inspection Effectiveness Examples for API RBI Damage Mechanisms ... 22 Table 8.1 – LoIE Example for General Thinning ... 22 Table 8.2 – LoIE Example for Local Thinning ... 23 Table 8.3 – LoIE Example for Amine Cracking ... 24 Table 8.4 – LoIE Example for Carbonate Cracking ... 25 Table 8.5 – LoIE Example for Caustic Cracking ... 26 Table 8.6 – LoIE Example for CLSCC ... 27 Table 8.7 – LoIE Example for PTA Cracking ... 28 Table 8.8 – LoIE Example for Sulfide Stress Cracking ... 29 Table 8.9 – LoIE Example for HIC/SOHIC-H2S Cracking ... 30 Table 8.10 – LoIE Example for HSC-HF Cracking ... 31 Table 8.11 – LoIE Example for HIC/SOHIC-HF Cracking ... 32 Table 8.12 – LoIE Example for External Corrosion ... 33 Table 8.13 – LoIE Example for External CLSCC Cracking ... 33 Table 8.14 – LoIE Example for CUI ... 34 Table 8.15 – LoIE Example for CUI CLSCC ... 35 Table 8.16 – LoIE Example for HTHA ... 36
1 SCOPE
This annex to the recommended practice provides a set of guidelines and examples of inspection effectiveness in order to aid in the establishment of an inspection program using risk-based methods for pressurized fixed
This annex to the recommended practice provides a set of guidelines and examples of inspection effectiveness in order to aid in the establishment of an inspection program using risk-based methods for pressurized fixed