The ASME Boiler and Pressure Vessel CodesBasic Training Course covering Section VIII Division 1 (2007Ed)Pressure Vessels

Non-Destructive Examination (NDE)

Nondestructive Examination

NDE Requirements, Section VIII Division 1

Objectives

• What methods of NDE are applicable to Section VIII and when theyare required?

• What are the acceptance criteria?

• What are the qualification requirements for NDE personnel?

• How NDE procedures are specified and qualified?

Nondestructive Examination

Section VIII Division 1 RT

When RT is to be used for Code construction, the requirements are found in:

• UW-2 Specific designs and service restrictions

• UW-9 Staggered joints

• UW-11 Definitions and applications

• UW-12 Efficiency requirements

• UW-42 Repairs and build up

• UW-51 Requirements for full RT

• UW-52 Requirements for spot RT

Nondestructive Examination

• RT/UT/MT/PT

NDE ASME Code Sec. V

App. I through VIIArticle 13 (Continuous Monitoring)

App. I, II & III, App A, BArticle 12 (for Metallic vessel)

App. I through IVArticle 5: for material

Article 30: Terminology for NDE Standard (SE-1316)

Article 14: Examination System Qualification (Calibration, Demonstration etc)

App. I, II & III, App. AArticle 29Article 11 (for FRP Vessel)ET

App. I through X, App. A-Article 10LT

App. I-Article 9VT

App. I through VArticle 26 (SE-243)Article 8ET

App. I, II & III, App AArticle 25 (SE-709)Article 7MT

App. I, II & IIIArticle 24(SE-165)Article 6PT

App. I & II, App. A through LArticle 23 (SA-435, SA-577)

Article 4: for weldsUT

App. I through App. VIIApp. A, C & D

Article 22 (SE-94,1025)Article 2RT

App.I Glossary of termApp.A Inspection vs Type of NDE

-Article 1: General Requirements

General

Mandatory & NonmandatoryAppendices

Subsection B Documents adopted by Sec V

Subsection ANDE Methods

NDE ASME Code Sec. V1) Terminology for NDE (SE-1316)

Imperfection – a departure of a quality characteristic from its intended condition

Indication – the response or evidence from a nondestructive examination

Evaluation – a review, following interpretation of the indications noted, to determine whether they meet specified acceptance criteria

False indication – an NDT indication that is interpreted to be caused by a condition other than a discontinuity or imperfection

Interpretation, n – the determination of whether indications are relevant, non relevant, or false.

Nonrelevant indication – an NDT indication that is caused by a condition or type of discontinuity that is not rejectable. False indications are non relevant.

Relevant indication – an NDT indication that is caused by a condition or type of discontinuity that requires evaluation

Defect – one or more flaws whose aggregate size, shape, orientation, location, or properties do not meet specified acceptance criteria and are rejectable.

Discontinuity – a lack of continuity or cohesion ; an intentional or unintentional interruption in the physical structure or configuration of a material or component.

2) Evaluation Steps

Nondestructive Testing

Indication

Interpretation

Relevant NonrelevantFalse

Evaluation

Accept Reject

3) Imperfection vs Type of NDE Method

NDE Sec. VIII Div.1(Summary)

Appendix 8Appendix 8Sec V Article 6YesPT

Appendix 6Appendix 6Sec V Article 7YesMT

SNT-TC-1AAppendix 12Sec V Article 4YesUT

SNT-TC-1AUW-51 or UW-52Sec V Article 2NoRT

NDE Personnel Qualification

Acceptance CriteriaNDE Requirements

Written Procedure Required

NDE Method

RT : If a written procedure is used, procedure demonstration is required.

(Sec. V T-221)

UT/PT/MT : A procedure qualification is required when an essential variable is changed (Table T-421 / T-621 / T-721)

NDE UT Procedure Qualification Requirements

NDE Special Services <UW-2>

Cat D

Cat C

Cat B

Cat A

-All butt joints -> RT

Cat A, B -> RTFillet -> MT/PT

All butt joints -> RT

NDE--F/P or P/PF/P--F/PType 1 or 2Type 1 or 2Type 1 or 2Type 1 or 2Type 1 or 2Type 1Type 1Type 1Type 1

P.V Direct Firing

Unfired Steam Boiler

Low Temp. Services

Lethal Services

Note) Type 1 or 2; butt joint

NDE Flow Chart for NDE Requirements

Determine ServicesU-2, UW-2

Full RT UW-11(a)

LethalUW-11(a)(1)

“T”UW-11(a)(2)

Unfired Steam boilersUW-11(a)(3)

Electroslag weldUW-11(a)(6)

Nozzle Butt weld

Spot RTUW-11(b)

No RTUW-11(c)

UHA-33UCS-57UHT-57

Plus UTUW-11(d))

UW-11(a)(4)

NDE RT Exemption for Butt Joint on Nozzle<UW-11(a)(2)/(4)/UW-11(b)>

A Nozzle/ChamberButt joint Cat B/C NPS ≤ 10 in No RT

T < 1 1/8 in

RT

NPS 10 SCH 120 – 1 1/8 inch

Yes Yes Yes

Yes

No

NDE Joint Efficiency (E) = 1.0 Application <UW-11(a)(5)>

* Except for Category B & C butt welds in nozzles and communicating chambers that neither exceed NPS 10 (DN 25) nor 1 1/8” (29mm) wall thickness.

Vessel Section / head

Type 1/2

Type 1/2

Full RT (UW-51)

AdditionalSpot RT(UW-52)

Cat A

Cat D

* Cat B

* Cat C

Butt

ButtConnect the

Seamless shell or head

Intersect the Cat. A butt joint

in shell or head

UW-11(a)(5)(a)

UW-11(a)(5)(b)

YesYes

Yes

Yes

Yes

Yes

Yes Yes

Yes

No

No

No

No

NDE Full RT is Mandatory (UCS Material)

NDE Additional RT Requirements

• UW-11(a)(1)All butt joints in the shell and heads of vessel -> Full RTNon-butt joint: No RT

• UHT-57(b)Nozzle attachments weld (Category D) in Fig UHT-18.2 -> Full RT

Abutt joint : RT

NDE Acceptance Criteria

Full RT <UW-51>UW-51 specifies requirements that must be complied with whenever full RT is used. Although it does not require a written procedure or record retention, it requires NDE personnel to be qualified to the applicable edition of SNT-TC-1A as a guide. If also specifies the acceptance criteria.

Acceptance CriteriaThe acceptance criteria for full RT are:

Linear indications:- No crack or zone of incomplete fusion or penetration.- Any elongated slag inclusion greater than :

* ¼” for t< ¾:*1/3” for t= 3/4 “ to 2-1/4: inclusive*3/4” for t>2-1/4”

- Any group of slag inclusion in line greater than t in a 12 t length except when the distance between inclusions is greater than 6 times the length of the longest inclusion. Acceptance criteria for rounded indications are found in Appendix 4.

NDE Acceptance Criteria

Spot RT <UW-52>

There are essentially the same as for full RT with the exception that it specifies the location and minimum number of exposures that must be made. Also, there is a significant differences in the acceptance criteria.

Acceptance CriteriaThe acceptance criteria for Spot RT are:

- No crack or zone of incomplete fusion or penetration.- Any elongated slag inclusion greater than

* 2/3 t * Any group of slag inclusions in line greater than t in a 6t length and the distance between the longest indications considered is greater than 3L, where L is the longest inclusion.

Rounded indications:- Rounded indications are not a factor in spot radiography.

NDE : RT requirements

RT 1

NDE : RT requirements

RT 1

NDE : RT requirements

RT 2

NDE : RT requirements

RT 2

NDE : RT requirements

RT 3

NDE : RT requirements

UW 51RT 3

NDE : RT requirements

UW 51RT 4

NDE Ultrasonic Examination

1) UW-11(a)(7)Substitution of RT for final closure seam of pressure vessel

2) UW-51(b)Substitution of RT for repaired area(UT before welding and AI acceptance are required)

3) UW-11(d) Electro slag welds in ferritic materials (Appendix 12 and UW-53)

4) UW-11(e)Electro beam welds (Appendix 12 andUW-53)

NDE Acceptance CriteriaUltrasonic Examination of Welds (App.12)

1) Imperfections to be investigateda response > 20% of the reference level

2) Acceptance standard(a) Indications characterized as cracks, lacks of fusion, or incomplete penetration

are unacceptable regardless of length. (b) Other imperfections are unacceptable if the indications exceed the reference

level amplitude and have lengths which exceed:(1) ¼ in. (6mm) for t up to ¾ in (19mm);(2) 1/3 for t from ¾ in to 2 ¼ in. (19mm to 57mm);(3) ¾ in. (19mm) for t over 2 ¼ in (57mm).

Where t = thickness of the weld excluding reinforcement the thinner of two thicknesses. Full penetration + fillet : the thickness + throat of fillet

NDE MT/PT Requirements① UG-93(d)(3)(4)

Corner joint (t>13mm) before/after welding on joint in FIG UW-13.2② UW-13(a)(2)

Longitudinal weld on one plate offset in fig. UW-13.1 sketch(k)③ UW-42(b)

Surface weld metal build-up (UW-9(c))④ UW-50

All welds around opening and all attachment welds in vessels to be pneumatic tested⑤ UHA-34

a) All welds in austenitic Cr/Ni all vessels whose shell thickness exceeds 19mmb) All welds in 36% Ni-steel vesselc) All welds in austenitic/ferritic duplex steel whose shell thickness exceeds 19mm required not

radiographed⑥ UHT-57

a) Nozzle attachment (ID ≤ 50mm)b) Corrosion-resistance overlay weld depositsc) All welds after hydrostatic testd) Welds (not radiographed) in vessels constructed of SA-333, Gr.8, SA-334 Gr.8, SA-353, SA-522,

SA-553 Gr. A/B and SA-645⑦ UHT-83(b)

Metal removal more than 1.6mm⑧ UHT-85

Temporary welds (After removal)

NDE MT/PT for Corner Joint

Flat Plate T ≥ ½ in Before welding After welding

MT/PT

Edge Prepared area (lamination) Lamellar tearing

NDE MT/PT for Corner Joint

1. Flat plate > ½ in2. MT/PT on edge preparation and after welding

NDE Acceptance Criteria

Magnetic Particle Examination (App. 6)

1) Relevant indication : major dimension > 1/16” (1.5mm)Linear indication : length > 3 x widthRounded indication : length ≤ 3 x width

(circular or elliptical type)

2) Acceptance StandardAll surfaces to be examined shall be free of:

(a) Relevant linear indications;(b) Relevant rounded indications greater than 3/16” (5mm)(c) Four or more relevant rounded indications in a line separated

by 1/15” (1.5mm) or less, edge to edge.

NDE Acceptance Criteria

Liquid Penetrant Examination (App. 8)

1) Relevant indication : major dimension > 1/16” (1.5mm)Linear indication : length > 3 x widthRounded indication : length ≤ 3 x width

(circular or elliptical shape)

2) Acceptance StandardAll surfaces to be examined shall be free of:

(a)Relevant linear indications;(b)Relevant rounded indications greater than 3/16” (5mm)(c) Four or more relevant rounded indications in a line

separated by 1/15” (1.5mm) or less, edge to edge.

NDE Section VIII NDE Summary

NDE required by the Code is summarised:

• RT of welding is required for special service or design ( UW 11, 12 etc )

• PT or MT prior to pneumatic tests ( UW- 50 )

• PT or MT of repairs or weld metal buildup ( UW- 42 )

• Visual examination during pressure test ( UG-99 )

MT / PT personnel can be qualified by the Manufacturer as per the following.

• Annual vision examination to Jaeger 2

• Competent in the technique, examining, interpretation and evaluation of the results.

• Demonstrate to the satisfaction of the A.I.