The ASME Boiler and Pressure Vessel Codes Basic Training Course covering Section VIII Division 1 (2007Ed) Pressure Vessels
Non-Destructive Examination (NDE)
Nondes Non destru tructi ctive ve Exa Examin minati ation on NDE NDE Requir Requir ement ements, s, Secti Section on VIII VIII Divisio Divis ion n1
Objectives •
What What met metho hods ds of of NDE NDE are are appl applic icab able le to to Sect Sectio ion n VIII VIII and and whe when n they they are required?
•
What hat are are the the acc accep epta tanc nce e cri crite teri ria? a?
•
What What are are the the qua qualilifi fica cati tion on req requi uire reme ment nts s for for NDE NDE pers person onne nel? l?
•
How How NDE NDE proc proced edur ures es are are spec specif ifie ied d and and qual qualif ifie ied? d?
Nondes Non destru tructi ctive ve Exa Examin minati ation on Secti Secti on VIII VIII Divis ion io n 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-1 UW-11 1
Defi Defini niti tio ons and appl applic ica ation tions s
•
UW-12
Efficiency requirements
•
UW-42
Repairs and build up
•
UW-51
Requirements for full RT
•
UW-52
Requirements for spot RT
Nondes Non destru tructi ctive ve Exa Examin minati ation on
• RT/UT/MT/PT
NDE NDE Methods General RT
ASME Code Sec. V Subsection A
Subsection B Documents adopted by Sec V
Mandatory & Nonmandatory Appendices
Article 1: General Requirements
-
App.I Glossary of term
Article 2
Article 22 (SE-94,1025)
App.A Inspection vs Type of NDE App. I through App. VII App. A, C & D
UT
Article 4: for welds
Article 23
App. I & II, App. A through L
Article 5: for material
(SA-435, SA-577)
App. I through IV
PT
Article 6
Article 24(SE-165)
App. I, II & III
MT
Article 7
Article 25 (SE-709)
App. I, II & III, App A
ET
Article 8
Article 26 (SE-243)
App. I through V
VT
Article 9
-
App. I
LT
Article 10
-
App. I through X, App. A
ET
Article 11 (for FRP Vessel)
Article 29
App. I, II & III, App. A
Article 12 (for Metallic Metallic vessel)
App. I, II & III, App A, B
Article 13 (Continuous Monitoring)
App. I through VII
Article 14: Examination System Qualification (Calibration, (Calibration, Demonstration etc) etc) Article 30: Terminology for for NDE Standard (SE-1316)
NDE 1)
ASME Code Sec. V
Terminology for ND NDE (SE-1316)
Imperfection – a departure of a quality characteristic characteristic from its intended condition Indication Indication – the response response or evidence evidence from a nondestructive examination Evaluation – a review, following following interpretation interpretation of the indications noted, to determine whether they meet specified acceptance criteria False indication – an NDT indication indication that is interpreted interpreted to be caused by a condition other than a discontinuity or imperfection Interpretation, n – the determination determination of whether indications are relevant, non relevant, or false. Nonrelevan Nonrelevantt indicatio indication n – an NDT indicati indication on that is caused caused by a condition or type of discontinuity that is not rejectable. False indications are non relevant. Relevant indication indication – an NDT indication indication that is caused by a condition or type of discontinuity that requires evaluation Defect – one or more flaws whose aggregate 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 Nondestructive Testing Indication Interpretation
False
Relevant
Nonrelevant
Evaluation
Accept
Reject
3) Imperfe Imperfection ction vs Type of NDE NDE Method Method
NDE
Sec. VIII Div.1(Summar
NDE Method
Written Procedure Required
NDE Requirements
Acceptance Acceptance Criteria
NDE Personnel Qualification
RT
No
Sec V Article 2
UW-51 or UW-52
SNT-TC-1A
UT
Yes
Sec V Article 4
Appendix 12 12
SNT-TC-1A
MT
Yes
Sec V Article 7
Appendix 6
Appendix 6
PT
Yes
Sec V Article 6
Appendix 8
Appendix 8
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
NDE
Special Services Lethal Services
Low Temp. Services
Unfired Steam Boiler
P.V Direct Firing
Cat A
Type 1
Type 1
Type 1
Type 1
Cat B
Type 1 or 2
Type 1 or 2
Type 1 or 2
Type 1 or 2
Cat C
Type 1 or 2
F/P
-
-
Cat D
F/P
F/P or P/P
-
-
All butt joints -> RT
Note) Type 1 or 2; butt joint
Cat A, B -> RT
All butt
Fillet -> MT/PT
joints -> RT
-
NDE
Flow Chart for NDE Requirements Determine Services U-2, UW-2 Full RT UW-11(a)
Lethal UW-11(a)(1)
“T” UW-11(a)(2)
UHA-33 UCS-57 UHT-57
Spot RT UW-11(b)
Unfired Steam boilers UW-11(a)(3)
Electr Electrosl oslag ag weld weld UW-11(a)(6)
Nozzle Butt weld UW-11(a)(4)
Plus UT UW-11(d))
No RT UW-11(c)
NDE
RT Exemption for Butt Joint on Nozzle
Yes
A
Nozzle/Chamber Butt joint
Yes Cat B/C
Yes No RT
NPS ≤ 10 in
Yes T < 1 1/8 in No RT
NPS 10 SCH 120 120 – 1 1/8 inch
NDE
Joint Efficiency (E) = 1.0 Applicatio ion n Vessel Section / head Yes
Type 1/2 UW-11(a)(5)(a)
Cat A
Yes
Yes
Butt
Full RT (UW-51)
No Cat D
Yes
No Type 1/2 UW-11(a)(5)(b)
* Cat B
Yes
No * Cat C
Yes
Yes Butt
Connect the Seamless shell or head
Yes
Additional Spot RT (UW-52)
No Intersect the Cat. A butt joint in shell or head
Yes
* 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.
NDE
Full RT is Mandatory (UCS Material)
NDE
Additional RT Requirements
• UW-1 UW-11( 1(a) a)(1 (1)) All butt joints in in the shell and heads heads of vessel -> Full Full RT Non-butt joint: No RT
• UHTUHT-57 57(b (b)) Nozzle attachments weld (Category D) in Fig UHT-18.2 -> Full RT
Abutt joint : RT
NDE
Acceptance Criteria
Full Ful l RT 1> UW-51 specifies requirements that must be complied with whenever full RT used. Although it does not require a written procedure or record record retention, requires NDE personnel to be qualified to the applicable applicable edition of SNT-TC as a guide. If also specifies the acceptance criteria.
Ac A c c ept ep t anc an c e Cri Cr i t eri er i a The acceptance criteria for full RT are: Linear indications: - No crack or zone zone of incomplet incomplete e fusion fusion or penetration. penetration. - Any elongate elongated d slag inclusi inclusion on greater greater than : * ¼” ¼” for for t< t< ¾: ¾: *1/3” *1/3” for t= 3/4 “ to 2-1/4: 2-1/4: inclus inclusive ive *3/4” *3/4” for t>2-1/ t>2-1/4” 4” - Any group of slag inclusion inclusion in line line greater than t in a 12 12 t length exc when the distance between inclusions is greater than 6 times the length of the longest inclusion. Acceptance criteria criteria for rounded indications indications are found in Appendix 4.
NDE
Acceptance Criteria
Spot RT There are essentially 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 Criteria The acceptance criteria for Spot RT are: - No cra crack ck or or zone zone of of inco incomp mple lete te fus fusio ion n or pen penet etra rati tion on.. - Any Any elo elong ngat ated ed slag slag incl inclus usio ion n gre great ater er than than * 2/3 t * Any group group of slag inclusion inclusions s in line greater greater than t in a 6t length and and the distan between the longest indications considered is greater than 3L, where L is the longest inclusion. Rounded indications: - Rounde Rounded d indi indicat cation ions s are are not not a fact factor or in in spot spot radiog radiograp raphy. hy.
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 51 RT 3
NDE : RT requirements UW 51 RT 4
NDE 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 Electro slag welds welds in in ferritic ferritic materials materials (Appendix 12 and UW-53) 4) UW-11(e) Electro beam welds (Appendix 12 and UW-53)
Ultrasonic Examination
NDE
Acceptance Criteria
Ultrasonic Examin Examination ation of Welds (App.12) (App.12) 1) Imperfections to be investigated a response > 20% of the reference level 2) Acceptance standard (a) Indication Indications s characterized characterized as cracks, cracks, lacks of fusion, fusion, or incomplete incomplete penetration penetration are unacceptable regardless of length. (b) Other imperfect imperfections ions are unaccepta unacceptable ble if the indications indications exceed exceed the reference reference level amplitude and have lengths which exceed: (1) (1) ¼ in. in. (6m (6mm) m) for for t up to ¾ in (19m (19mm) m);; (2) (2) 1/3 1/3 for for t fro from m ¾ in to to 2 ¼ in. in. (19m (19mm m to to 57m 57mm) m);; (3) (3) ¾ in. in. (19 (19mm mm)) for for t ove overr 2 ¼ in (57m (57mm) m).. Where t = thickness of the weld excluding reinforcement the thinner of two thicknesses. Full penetration + fillet : the thickness + throat of fillet
NDE
MT/PT Requirements
① UG-93(d)(3)(4)
Corner joint (t>13mm) before/after welding on joint in FIG UW-13.2 ② 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 around opening opening and all all attachment attachment welds in vessels vessels to be be pneumatic pneumatic tested ⑤ UHA-34 a) All welds in austenitic austenitic Cr/Ni all vessels whose whose shell thickness thickness exceeds exceeds 19mm b) All welds welds in 36% Ni-steel Ni-steel vessel vessel c) All welds in austenitic/fe austenitic/ferritic rritic duplex steel steel whose shell shell thickness thickness exceeds 19mm required required not radiographed ⑥ UHT-57 a) Nozzle attachment (ID ≤ 50mm) b) Corrosion-resistance overlay weld deposits c) All welds after hydrostatic test d) 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-645 ⑦ UHT-83(b) Metal removal more than 1.6mm ⑧ UHT-85 Temporary welds (After removal)
NDE
Flat Plate
MT/PT MT/ PT for Cor Corner ner Joi Joint nt
T ≥ ½ in
Before welding
Edge Prepared area (lamination)
After welding
Lamellar tearing
MT/PT
NDE
MT/PT for Corner Joint
1. Flat plate > ½ in 2. MT/PT MT/PT on edge edge prep prepara aratio tion n and and after after weldin welding g
NDE
Acceptance Criteria
Magnetic Particle Examination (App. 6) 1) Relevant indication : major dimension > 1/16” (1.5mm) Linear indication : length > 3 x width Rounded indication : length ≤ 3 x width (circular or elliptical type) 2) Acceptance Standard All surfaces to be examined shall be free of: (a) Relevant Relevant linear linear indic indication ations; s; (b) Relevant Relevant rounded rounded indic indication ations s greater greater than 3/16” (5mm) (c) Four or more releva relevant nt rounded rounded indication indications s in a line separated separated by 1/15” 1/15” (1.5mm) (1.5mm) or less, less, edge edge to edge. edge.
NDE
Acceptance Criteria
Liquid Liquid Penetrant Penetrant Examinati Examination on (App. (App. 8) 1) Relevant Relevant indication indication : major major dimension dimension > 1/16” (1.5mm) (1.5mm) Linear indication : length > 3 x width Rounded indication : length ≤ 3 x width (circular or elliptical shape) 2) Acceptance Standard All surfaces to be examined shall shall be free of: (a) Relevant Relevant linear indications; indications; (b) Relevant Relevant rounded rounded indica indications tions greater greater than 3/16” (5mm) (c) Four or more relevant rounded indications in a line separated separated by 1/15” 1/15” (1.5mm) (1.5mm) or less, less, edge to edge. edge.
NDE
Section VIII NDE Summary
NDE required by the Code is summarised: •
RT of weld weldin ing g is requ requir ired ed for for spec specia iall serv servic ice e or desi design gn ( UW 11, 11, 12 etc etc )
•
PT or MT prior to pneumatic tests ( UW- 50 )
•
PT or MT of repa repair irs s or weld eld meta metall bui buildup ldup ( UWUW- 42 )
•
Visu Visual al exam examin inat atio ion n duri during ng pres pressu sure re test test ( UG-9 UG-99 9)
MT / PT personnel can be qualified by the Manufacturer as per the following. •
Annu Annual al visi vision on exam examin inat atio ion n to Jaeg Jaeger er 2
•
Compet Competent ent in the techni technique que,, exam examini ining, ng, interp interpret retati ation on and evalua evaluatio tion n of the results.
•
Demo Demons nstr trat ate e to to the the sati satisf sfac acti tion on of the the A.I A.I..
