NES 729 Part 5 Requirements for Non-Destructive Examination Methods

Ministry of Defence Defence Standard 02-729 (NES 729) Issue 1 Publication Date 01 April 2000

Requirements For Non-Destructive Examination Methods Part 5 Ultrasonic

Incorporating NES 729 Category 2 Issue 1 Publication Date November 1984

AMENDMENT RECORD Amd No

D at e

Text Affected

REVISION NOTE

This standard is raised to Issue 1 to update its content. HISTORICAL RECORD This standard supersedes the following:

Naval Engineeri En gineering ng Standard Standar d (NES) 729 72 9 Part 5 Issue 1 dated November Nov ember 1984.

S i g n at u r e a n d D at e

Ministry of Defence

Naval Engineering Standard

NES 729 Part 5

Issue 1 (Reformatted)

November 1984

REQUIREMENTS FOR NON-DESTRUCTIVE EXAMINATION METHODS PART 5 ULTRASONIC

This NES Supersedes DGS/PS/9022 PART 6

Record of Amendments AMDT 1 2 3 4 5 6 7 8 9 10

INSERTED BY

DATE

NAVAL ENGINEERING STANDARD 729 REQUIREMENTS FOR NON-DESTRICTIVE EXAMINATION METHODS PART 5 ISSUE 1 (REFORMATTED) ULTRASONIC

The issue and use of this Standard is authorized for use in MOD contracts by MOD(PE) Sea Systems and the Naval Support Command

ECROWN COPYRIGHT

Published by: Director of Naval Architecture Procurement Executive, Ministry of Defence Sea Systems, Foxhill, Bath BA1 5AB i

ii

NES 729 Part 5 Issue 1 (Reformatted)

SCOPE 1.

This NES covers the procedures and methods to be used for the Quality Assessment of Ultrasonic Examining Authorities and for production ultrasonic examination. The methods described are the minimum requirements for the detection of surface and sub-surface imperfections in welded and brazed joints, cast and wrought materials and for the measurement of plate and tube wall thickness, but does not contain acceptance criteria for defects thus revealed. Manual methods only are covered but automatic and mechanically assisted methods and associated recording systems are to be applied whenever the extent of the examination justifies the need to minimize operator induced variables and the equipment cost.

2.

The effective application of ultrasonic examination may be restricted in materials with inherently high or variable attenuation or which produce severe scattering of the ultrasonic beam. Complex shapes may also limit satisfactory application and the examination is to be applied at stages during manufacture when the geometry of the component is relatively simple provided that subsequent specified treatments of the material do not render the examination ineffective.

3.

The extent to which ultrasonic examination is required is not included herein. This will be stated in the Contract Documents.

4.

This NES does not apply to nuclear plant and machinery to which DG Ships/PS/5108 applies.

iii


iv


FOREWORD Sponsorship 1.

This Naval Engineering Standard (NES) is sponsored by the Procurement Executive, Ministry of Defence (MOD(PE)), Deputy Controller Warships (DCW), Section NA 133.

2.

It is to be applied as required by any MOD(PE) contract for the non-destructive examination of metals and is applicable to Surface Ships and Submarines.

3.

This NES comprises: Requirements for Non-destructive Examination Methods Part 1

Radiographic

Part 2

Magnetic Particle

Part 3

Eddy Current

Part 4

Liquid Penetrant

Part 5

Ultrasonic

4.

If it is found to be technically unsuitable for any particular requirement the sponsor is to be informed in writing of the circumstances with a copy to Deputy Controller Warship Equipment (DCWE), Section TE 112a.

5.

Any user of this NES either within MOD or in outside industry may propose an amendment to it. Proposals for amendments which are: a.

not directly applicable to a particular contract are to be made to the sponsor of the NES.

b.

directly applicable to a particular contract are to be dealt with using existing departmental procedures or as specified in the contract.

6.

No alteration is to be made to this NES except by the issue of a formal amendment.

7.

Unless otherwise stated, reference in this NES to approval, approved, authorized or similar terms means by the Procurement Executive, Ministry of Defence.

8.

Any significant amendments that may be made to this NES at a later date will be indicated by a vertical side line. Deletions will be indicated by 000 appearing at the end of the line intervals.

Conditions of Release

General 9.

This Naval Engineering Standard (NES) has been prepared for the use of the Crown and of its contractors in the execution of contracts for the Crown. The Crown hereby excludes all liability (other than liability for death or personal injury) whatsoever and howsoever arising (including but without limitation, negligence on the part of the Crown, its servants or agents) for any loss or damage however caused where the NES is used for any other purpose.

10.

This document is Crown Copyright and the information herein may be subject to Crown or third party rights. It is not to be released, reproduced or published without written permission of the MOD.

11.

The Crown reserves the right to amend or modify the contents of this NES without consulting or informing any holder.

v


MOD Tender or Contract Process 12.

This NES is the property of the Crown and unless otherwise authorized in writing by the MOD must be returned on completion of the contract, or submission of the tender, in connection with which it is issued.

13.

When this NES is used in connection with a MOD tender or contract, the user is to ensure that he is in possession of the appropriate version of each document, including related documents, relevant to each particular tender or contract. Enquiries in this connection may be made of the local MOD(PE) Quality Assurance Representative or the Authority named in the tender or contract.

14.

When NES are incorporated into MOD contracts, users are responsible for their correct application and for complying with contracts and any other statutory requirements. Compliance with an NES does not of itself confer immunity from legal obligations.

Related Documents 15.

In the tender and procurement processes the related documents listed in each section and Annex A can be obtained as follows: a.

British Standards

British Standards Institution, 389 Chiswick High Road, London W4 4AL

b.

Defence Standards

Directorate of Standardization and Safety Policy, Stan 1, Kentigern House, 65 Brown Street, Glasgow G2 8EX

c.

Naval Engineering Standards

CSE3a, CSE Llangennech, Llanelli, Dyfed SA14 8YP

d.

Other documents

Tender or Contract Sponsor to advise.

Note: Tender or Contract Sponsor can advise in cases of difficulty. 16.

All applications to Ministry Establishments for related documents are to quote the relevant MOD Invitation to Tender or Contract Number and date, together with the sponsoring Directorate and the Tender or Contract Sponsor.

17.

Prime Contractors are responsible for supplying their subcontractors with relevant documentation, including specifications, standards and drawings.

Health and Safety

Warning 18.

This NES may call for the use of processes, substances and/or procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and in no way absolves either the supplier or the user from statutory obligations relating to health and safety at any stage of manufacture or use. Where attention is drawn to hazards, those quoted may not necessarily be exhaustive.

vi


CONTENTS Page No

TITLE PAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

i

SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sponsorship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conditions of Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MOD Tender or Contract Process . . . . . . . . . . . . . . . . . . . . . . . . . . Related Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Health and Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

v v v v vi vi vi vi

CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vii

SECTION

1.

ACCEPTANCE STANDARDS . . . . . . . . . . . . . . . . .

1.1

SECTION

2.

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.1

SECTION

3. 3.1 3.2

GENERAL INSPECTION REQUIREMENTS . . . . Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Personnel Requirements . . . . . . . . . . . . . . . . . . . . . . FIGURE 3.1 SPECIMEN—ULTRASONIC EXAMINATION PROCEDURE . . . . . . . . . . . . . . . . Equipment Requirements . . . . . . . . . . . . . . . . . . . . . Equipment Performance Characteristics . . . . . . . . . Equipment Qualification . . . . . . . . . . . . . . . . . . . . . . Sensitivity Calibration Reference/Test Blocks . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Surface Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.1 3.1 3.1

4.7

PLATE MATERIAL . . . . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Compressional Wave Inspection . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Shear Wave Examination . . . . . . . . . . . . . . . . . . . . . . TABLE 4.1 NOTCH DIMENSIONS . . . . . . . . . . . . Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1 4.1 4.1 4.1 4.1 4.2 4.2 4.2 4.3

SECTION

5. 5.1 5.2 5.3

PLATE THICKNESS MEASUREMENT . . . . . . . . Instrument Calibration . . . . . . . . . . . . . . . . . . . . . . . Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . .

5.1 5.1 5.1 5.1

SECTION

6. 6.1

BUTT WELDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1 6.1

3.3 3.4 3.5 3.6 3.7 3.8 SECTION

4. 4.1 4.2 4.3 4.4 4.5 4.6

vii

3.2 3.3 3.3 3.4 3.4 3.5 3.5


6.2

6.3 6.4 6.5 6.6

SECTION

SECTION

7. 7.1 7.2 7.3

Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TABLE 6.1 BEAM ANGLES . . . . . . . . . . . . . . . . . . TABLE 6.2 USE OF T-TYPE PROBES . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 6.1 REFERENCE/TEST BLOCKS FOR WELD THICKNESS UP TO AND INCLUDING 38mm . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 6.2 REFERENCE/TEST BLOCKS FOR WELD THICKNESS GREATER THAN 38mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 6.4 REFERENCE/TEST BLOCK FOR WELD STRADDLE SCANNING . . . . . . . . . . . . . . . FIGURE 6.5 REFERENCE/TEST BLOCK DIAGRAMMATIC SET-UP FOR STRADDLE SCAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.1 6.1 6.1 6.2 6.2 6.2 6.3

6.4

6.4 6.6

6.6 7.1 7.1 7.1 7.1

7.4 7.5 7.6 7.7 7.8 7.9 7.10

TEE-BUTT WELDING . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Test Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 7.1 COMBINATION BLOCK COVERING DIFFERENT WELD AND PLATE THICKNESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Plotting Weld Width . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Search Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . Search Scanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Defect Indication Measurement . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8. 8.1 8.2 8.3 8.4 8.5 8.6 8.6.1 8.6.2 8.6.3 8.6.4 8.7

OVERLAY CLADDING . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration/Test Block . . . . . . . . . . . . . . . . . . . . . . . . Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manually deposited cladding . . . . . . . . . . . . . . . . . . . Procedure tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Machine deposited cladding . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.2

viii

7.2 7.3 7.3 7.3 7.3 7.3 7.4 7.4


SECTION

9. 9.1 9.2 9.3 9.4 9.5 9.6 9.7

BRAZED PIPE JOINTS . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 9.1 TYPICAL CRT DISPLAYS . . . . . . . .

9.1 9.1 9.1 9.1 9.1 9.1 9.2 9.2 9.4

SECTION

10. 10.1 10.2 10.3 10.4 10.5

PIPES AND TUBES . . . . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10.1 10.1 10.1 10.1 10.1 10.1

SECTION

11.

PIPE OR TUBE WALL THICKNESS MEASUREMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.1 11.1 11.1 11.1 11.1 11.1 11.1 11.1

12.4 12.5 12.6

FORGINGS—INCLUDING FORGED, EXTRUDED AND WROUGHT BARS . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURE 12.1 REFERENCE STANDARD . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12.1 12.1 12.1 12.1 12.2 12.3 12.3 12.3

SECTION

13. 13.1 13.2 13.3 13.4 13.5 13.6

CASTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Method of Examination . . . . . . . . . . . . . . . . . . . . . . . Assessment of Defects . . . . . . . . . . . . . . . . . . . . . . . . .

13.1 13.1 13.1 13.1 13.1 13.1 13.2

SECTION

14.

SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14.1

ANNEX

A.

RELATED DOCUMENTS . . . . . . . . . . . . . . . . . . . .

A.1

ANNEX

B.

DEFINITIONS AND ABBREVIATIONS . . . . . . . .

B.1

ANNEX

C.

PROCUREMENT CHECK LIST . . . . . . . . . . . . . . .

C.1

11.1 11.2 11.3 11.4 11.5 11.6 11.7 SECTION

12. 12.1 12.2 12.3

ALPHABETICAL INDEX

ix


x


1.

ACCEPTANCE STANDARDS a.

The standards for acceptance of defect indications detected by ultrasonic examination are to be as specified in the Contract Documents. Where not specified therein, DG Ships/G/10000B, DG Ships/PS/9010B or DG Ships 86C are to apply as appropriate.

1.1


1.2


2.

INSPECTION a.

It is not the intent of this NES to exclude proven inspection procedures which can be demonstrated to the satisfaction of the MOD QAR to meet the quality requirements. Prior approval is to be obtained before such procedures are used.

b.

Unless otherwise specified in the Contract Documents, acceptance inspection is to be performed on an item in the final surface condition and the final heat treated condition.

2.1


2.2


3.

GENERAL INSPECTION REQUIREMENTS

3.1

Test Procedure a.

Ultras Ultrasoni onicc examin examinati ation on is to to be perfo performe rmed d in accord accordanc ance e with a writ written ten test test proced procedure ure.. Each Each Examin Examining ing Author Authority ity is to certif certify y that that the procedure procedure is in accord accordanc ance e with with this this NES and is to submit submit each each proce procedu dure re to the MOD QAR for written approval.

b.

The test test proc procedu edure re is to includ include e the the follo following wing informa informatio tion: n: (1)

Descri Descriptiv ptive e compon component ent details details includ including ing materi material al type, type, shape shape and size; size; for welds: the weld preparation and welding details. Sketches as necessary. Surface finish.

(2)

Equipme Equipment nt details: details: model model or type and and make, make, monitori monitoring ng and record recording ing details. Special features, ie probe guides or saddles. saddles. Positive Positive identification or probes, types, makes, including transducer sizes, frequency and beam angles. Couplant type.

(3)

Techniqu Technique e details: details: scanning scanning method, method, ie manual, manual, automat automated, ed, immersion immersion etc. Scanning directions directions and the test surfaces surfaces used. used.

(4)

Calibra Calibratio tion n proced procedure uress and sensit sensitivit ivity y checks checks with detail detailss of refere reference nce bloc blocks ks used used.. The The meth method od and and freq freque uenc ncy y of sens sensit itiv ivit ity y chec checks ks in production.

(5)

The meth method od of reco recordi rding ng the result resultss of exam examinat ination ion..

(6)

Pre examinat examination ion and and post post examination examination cleaning cleaning methods methods as applicable. applicable.

A suitable form for ultrasonic procedure is given as FIGURE 3.1.

3.2

Personnel Requirements a.

The The Exam Examini ining ng Autho Authorit rity y is to ensure ensure that all all personn personnel el associ associat ated ed with with ultrasonic examination have been adequately trained to the levels appropriate to their their respo respons nsibi ibilit litie iess and and main mainta tain in reco record rdss acco accord rdin ingly gly.. Perso ersonn nnel el performing and interpreting ultrasonic examination are to be able to carry out an operation operational al type type test test using using the test test method method or techni technique que to be used used in production. production. The Examining Examining Authority Authority is to be able to interpret the results results and be familiar with the standards to which they are working. Personnel are to be considered qualified when they have demonstrated their ability to meet the requirements of the approved procedure. Personnel are to be conversant with the effects of: (1) (1)

surf surfac ace e cond condit itio ion; n;

(2)

material material structure structure (grain size, attenuatio attenuation n etc);

(3)

transducer transducer size size and type (compressio (compressional, nal, shear and surface surface wave; wave;

(4) (4)

the the effe effect ct of dead dead zone zone;;

(5) (5)

test test freq freque uenc ncy; y;

(6)

acous acoustic tic coupla couplant; nt;

(7) (7)

meth method od of calib calibra rati tion on;;

(8) (8)

use use of atte attenu nuat ator or;;

(9)

displa display y charac character terist istics ics;;

(10) flaw indication indication measure measurement. ment.

3.1


Procedure No . . . . . . . . . . . . . . . . Comp Compan any y................... ................... ...................

Issu Issue e No No . . . . . . . . . . . . . . Date Date . . . . . . . . . . . . . . . Proc Proced edur ure e draf drafte ted d by . . . . . . . . . . . . . . . . . . . . . . . . . . . Appr Approv oved ed by by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exam Examin inat atio ion n cond conduc ucte ted d by . . . . . . . . . . . . . . . . . . . . . .

COMPONENT DESCRIPTION Titl Title e................. ..... Drg Drg No . . . . . . . . . . . . . . . . . . . . Materials specification . . . . . . . . Area Examined (a) (a) Loca Locati tion on . . . . . . . . . . . . . . . . .

Contract Order No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mate Materi rial al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Casting/Forging/Weld/Other . . . . . . . . . . . . . . . . . . . . . . (b) (b) Thic Thickn knes esss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TECHNIQUE DETAILS 1.

Ins Instrumentation ion (a) (a) (b) (b) (c) (c)

Driv Drive e Uni Unitt Mak Make e . . . . . Mode Modell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moni Monito tor( r(s) s) Mak Make e . . . . . Mode Modell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reco Record rder er(s (s)) Make Make . . . . Mode Modell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Probe(s) Type: Twin crystal/Single. Crys Crysta tall type type . . . . . . . . . . . . . . Size Size . . . . . . . . . . . . 2.

Freq Freque uenc ncy y . . . . . . . . . . . . . . MHz MHz..

Type of Test Automatic/Immersion/Irrigated Probe/Manual/Contact Couplant: Water/Glycerol/Cellulose paste/other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scan control: Mechanical/Template guide/other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.

Sens Sensit itiv ivit ity y Cali Calibr brat atio ion n Test est piece piece mate materia riall . . . . . . . . .

Thic Thickn knes ess( s(es es)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Calibration Target (a) (a) Flat Flat Bott Bottom om Hole Hole:: Diam Diamet eter er . . . . mm mm Beam Beam path path leng length th . . . . . . . . . . . . . . . . . . . . . . (b) (b) Notc Notch h len lengt gth h . . . . . . . . . . . . . . . . mm mm 4.

Dept Depth h . . . . . . . . . . . . . . . . . . . mm. mm. Dept Depth h . . . . . . . . . . mm mm. Width idth . . . . mm. mm.

Scanning ing Details ils Directions, surfaces used, and coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diag Diagra rams ms to be used used as nece necess ssar ary y. ... ... ...... ... ... ... ... ... ... ... ... ...

5.

Acce Accept ptan ance ce Stan Standa dard rd Spec Specif ific icat atio ion n

6.

Supp Supple leme ment ntar ary y Info Inform rmat atio ion n

FIGURE 3.1 SPECIMEN—ULTRASONIC SPECIMEN—ULTRASONIC EXAMINATION EXAMINATION PROCEDURE

3.2


3.3

Equipment Requirements a.

3.4

Ultrasonic equipment is to consist of the following: (1)

Electronic apparatus capable of producing, receiving and displaying high frequency electrical pulses at the required frequencies and energy levels. The apparatus is to have the capability to meet the calibration requirements for specific tests and feature a calibrated attenuator. The display is to include a well defined and permanently marked graticule.

(2)

Probes, single and double types, capable of transforming electrical impulses into mechanical ultrasonic vibrations and vice versa at specific frequencies. Probes are to be capable of transmitting the ultrasound into the material and/or receiving the returning energy via a suitable coupling medium.

(3)

Couplant liquid or gel having good wetting properties for the transference of mechanical ultrasonic vibration to and from the test surface. Environmental conditions may preclude the use of all couplant types other than water.

(4)

Calibration blocks for the assessment of probe and electronic apparatus, characteristics and performance.

(5)

Reference/Test blocks for the pre-test calibration procedure with which to set the applicable acceptance or rejection test level to aid interpretation and the reproduction of test results.

Equipment Performance Characteristics a.

Note:

Prior to use in production, inspection, after maintenance or at intervals not exceeding one month, the following equipment performance characteristics are to be assessed and the results recorded, using block A2 to BS 2704 and the methods in BS 4331 (Parts 1 and 3): (1)

time base linearity over the required working range;

(2)

linearity of amplifier;

(3)

swept gain (if featured);

(4)

overall system gain;

(5)

Signal-to-Noise ratio;

(6)

calibrated attenuator accuracy;

(7)

beam characteristics, dead zone and resolution;

(8)

probe(s) angle(s) of refraction and index points. Suppression/Reject and Swept Gain controls are to be in the ‘OFF’ position when checking linearity of amplifier.

3.3


3.5

Equipment Qualification a.

Equipment is to be considered qualified when records of the characteristics in accordance with Clause 3.4a. show: (1)

time base linearity measured between at least five multiple echoes is within ± 1%;

(2)

amplifier linearity ± 1dB, ie the difference in the attenuator figures noted in reducing a backwall echo from a steel sample from 80% Full Screen Deflection (FSD) to 40% FSD to 20% is to be 6dB ± 1dB in each case;

(3)

swept gain signal amplitudes are within ± 2dB over the working range observing at least five multiple echoes;

(4)

overall system gain with at least 35dB in reserve using a 20% FSD echo from the 1.5mm hole in the A2 test block. (See BS 4331, Part 3, Fig 16);

(5)

Signal-to-Noise Ratio based on a 20% FSD echo from the 1.5mm hole in the A2 test block. This echo is to exceed noise level by 12dB;

(6)

calibrated attenuator covers the working range required in steps not greater than 2dB with an accuracy of ± 1dB over any 20dB range;

(7)

minimum resolution of compressional wave probes complies with BS 2704 Fig 13c;

(8)

minimum resolution of shear wave probes using test block to BS 3923 Part 3, Fig 1a. 2 to 6MHz probes shall be capable of resolving the 2mm step;

(9)

the area of each transmitting and/or receiving crystal does not exceed 350 square mm and that no dimension of the crystal face exceeds 25mm;

(10) probe angle of refraction is within ± 2 degrees of stipulated angle; (11) probe index point as marked is within 1mm of that measured using the A2 test block. b.

3.6

The above equipment checks inherently qualify both the probe and the electronic equipment. It is essential therefore that qualification is established for each probe that is to be used.

Sensitivity Calibration Reference/Test Blocks a.

Immediately prior to the examination of each item the required equipment sensitivity is to be established by the use of reference/test blocks which simulate the item as regards to the material type and thickness range. The test blocks are to contain suitable calibration target reflectors, eg flat bottom holes or slots, in simulation of the characteristics of defect types expected to occur in the item to be examined. The targets are to be positioned away from other reflecting surfaces to ensure they can be clearly and individually resolved by the equipment used.

3.4


3.7

3.8

Method of Examination a.

A controlled reproducible examination at the specified sensitivity is to be consistently achieved and maintained.

b.

The equipment is always to be calibrated to the appropriate reference standards before the examination begins. Calibration is to be checked at intervals during the examination.

c.

Probe characteristics and probe movement, signal amplitude and the material attenuation effects are to be taken into consideration when the significance of defects is being assessed.

d.

The movement or rotation of the probes or test item is to be controlled as closely as possible to maintain a uniform testing speed. The test speed is not to exceed the maximum speed at which the reference standard can be scanned and produce clear resolution of the targets, and is to be consistent with operator readout efficiency.

e.

It may be necessary to verify indications of defects revealed during ultrasonic examination by the use of an alternative ultrasonic technique or non-destructive test method.

f.

The attenuation difference between the test material and that of the simulation test block is to be compared by the use of the first backwall echo height in compressional wave examination, and by the use of a target corner echo height for shear wave examination. As necessary the equipment sensitivity is to be adjusted to compensate for attenuation variations between the test item and the test block. These adjustments will normally be minimal and it must be ensured that the signal from the least apparent calibration target is still detectable. On test items that do not present a target corner for the shear wave examination, the attenuation difference established with the compressional wave probe is to be used.

g.

The use of a distance amplitude curve is recommended. Curves are to be constructed for the particular equipment combination in use.

h.

The effect of ‘dead zone’ under the probe is to be minimized by a complementary examination from the opposite surface to that first used on the item under test or by the use of a twin crystal probe unless the material in the ’deed zone’ is subsequently to be removed by machining.

Surface Finish a.

The surface of the item to be tested is to be clean and free from dirt, loose scale or paint or other foreign matter to ensure effective acoustic coupling and test. Ideal surfaces are those smooth and clean to bright metal. On completion of the test the couplant is to be removed in accordance with the requirements of the specification applicable to the test item.

3.5


3.6


4.

PLATE MATERIAL

4.1

Application a.

4.2

Surface Preparation a.

4.3

The plate is to be in the pickled, shot or abrasive condition and the test surface is to comply with Clause 3.8a. The test surface may have one coat of primer. As necessary the surface may be smoothed to assure effective acoustic coupling and test.

Compressional Wave Inspection a.

4.4

The methods described are to be used for the examination of plate material of 6mm thickness and greater.

The test frequency range is 2 to 5MHz. The transducer size is to conform to the requirements in Clause 3.5a.

Calibration a.

A test block is to be prepared from sound material of the same material group (ie low alloy steel, austenitic stainless steel, copper nickel, monel etc) and within ± 10% of the thickness of the material to be examined: (1)

For plate material up to and including 25mm thick, a 6mm dia flat bottom hole is to be drilled from one plate surface to depth one half of the test block thickness.

(2)

For thicknesses over 25mm two or more 6mm dia flat bottom holes will be required. Holes are to be drilled from one plate surface to depths 12mm from each surface, and intermediate such that the difference in the depths of successive holes does not exceed 26mm, eg: 28mm thickness—2 holes minimum—12mm and 26mm deep 50mm thickness—2 holes minimum—12mm and 38mm deep 75mm thickness—3 holes minimum—12mm, 38mm and 63mm deep 100mm thickness—4 holes minimum—12mm, 38mm, 63mm and 88mm deep.

(3)

The time base is to be calibrated and the graticule marked to show nominal plate thickness.

(4)

Maintaining the same gain control position throughout, the instrument sensitivity is to be adjusted to display a 20% Full Screen Deflection (FSD) at each of the following stages, and the indicated attenuator figure recorded:

(5)

The first backwall echo through an undrilled section of the test block

= eg A dB

The least detectable hole in the test block

= eg B db

The first backwall echo through the plate to be examined

= eg C dB

Each of the remaining holes in the test block

= eg D db etc

The difference between attenuator figures A and C will be the compensating factor to be used in the production examination. The Minimum Search Sensitivity will be C ! (A ! B) dB.

4.1


(6)

Note:

4.5

Where the amplitude of the first backwall echo is reduced to 20% FSD or less unaccompanied by evidence of laminar inclusions, the plate surfaces are to be checked and dressed if necessary to ensure adequate acoustic coupling.


4.6

The assessment of defect significance is to be made relative to the depth of the indication below the test surface. Defects at depths other than that of the least detectable hole, are to be assessed using an adjusted search sensitivity value derived by substituting the attenuator figure recorded for the equivalent depth hole in the test block.

Each plate is to be marked on one major surface with grid lines normal to the direction of rolling and separated by not more than 5% of the plate width or 90% of the transducer diameter whichever is the greater. Each grid line is to be scanned in accordance with Clauses 4.6b. and 4.6c. In addition each edge of the plate is to be similarly scanned along a parallel track not exceeding 50mm from the edge, unless included in the grid pattern.

Shear Wave Examination a.

Where examination using shear wave is specified or required, the shear wave sensitivity is to be set to a reference notch of dimensions given in TABLE 4.1. The notch is to be suitably positioned in a reference/test block that conforms to Clause 3.6a. The instrument calibration is to be carried out using a shear wave probe of suitable angle and frequency. The time base of the oscilloscope is to be calibrated by obtaining peak amplitude reflections from the notch at half-skip distance, ie with probe placed on the surface opposite the notch; and at full-skip distance, ie with the probe placed on the surface containing the notch. The test sensitivity is to be such that the minimum signal amplitude from the notch at full skip distance is 20% FSD. Equipment sensitivity is to be adjusted to compensate for attenuation variation between the item under test and the test block. SQUARE NOTCH DIMENSIONS

Depth of notch—expressed as a percentage of plate thickness

3% or 0.1mm whichever is the greater

Width of notch

2 ¢ depth

Length of notch

approx 40mm TABLE 4.1 NOTCH DIMENSIONS

b.

Shear wave testing is to be performed by scanning one major surface in two directions, ie parallel to and normal to the direction of rolling of the plate. The probe unit is to be moved in parallel paths. In the event of defect indication that approaches in amplitude that of the reference notch, the adjacent area is to be scanned by the continuous method indexing approximately 90% of the width of the transducer sufficient to establish the size and location of the discontinuity.

c.

Detection of a defective area or an area of attenuation wholly contained within a 75mm diameter circle is to require 100% examination of adjacent material within 600mm of the defect. Detection of a laminar inclusion is to require 100% check of adjacent material within 300mm of the defect. Details are to be recorded as required by Clause 4.7a.

4.2


4.7

Recording a.

The following information is to be recorded in addition to the test procedure: (1)

location and size of any true lamination;

(2)

location and size of any area where the first backwall echo is attenuated to 20% FSD or less after plate surface preparation;

(3)

location and size of laminar inclusions having a reflectivity in excess of the equivalent depth 6mm dia hole;

(4)

when using shear waves the location and signal amplitude of any indication above the reference level (Clause 4.6a.)

4.3


4.4


5.

PLATE THICKNESS MEASUREMENT a.

5.1

5.2

Instrument Calibration a.

Calibration is to be carried out using a suitable test block of the same material type and of thickness that is within the permitted thickness tolerance applicable to the item to be tested. Direct readout instruments are to be calibrated and checked for drift, suitability and accuracy in accordance with the instrument manufacturer’s instructions.

b.

Test blocks may consist of machined step wedges or a series of machined discs that cover the range of materials and thicknesses to be tested. Blocks and discs are to be clearly marked preferably by engraving to indicate material type and thickness.

Coverage a.

5.3

Plate thickness may be measured by using conventional pulse-echo flaw detection equipment or direct readout ultrasonic thickness gauging instruments with meter or digital display. Flaw detection equipment is to comply with Clause 3.5a. Direct readout instruments are to be used only for measurement of thickness within the manufacturer’s marked ranges and provided that the instrument accuracy is within the permitted thickness tolerance for the item to be tested.

The extent of coverage of thickness gauging is to be as specified in the Contract Documents. Thickness gauging of plate carried out in conjunction with Clause 4.5a. is to be measured on the grid lines at intervals not greater than 600mm. Reference to DG Ships 137 may also be required.


Plates are to be free from any surface imperfection that will interfere with the test. Surface imperfections may be removed by wire brushing or light grinding to sound metal provided the thickness is not reduced below the minimum thickness permitted by specification and the ground area faired into the surrounding metal.

5.1


5.2


6.

BUTT WELDING

6.1

Application a.

6.2

The application of ultrasonic methods to the examination of butt welds is influenced by the types of materials in use, their thickness and geometry, and the required flaw sensitivity. The influence of the properties of the structure in the weld and heat affected zone may restrict application. The use of modified probes may be essential where testing is carried out on materials which have differing acoustic velocities to those for which commercial probes are normally designed. When testing these materials it will be necessary to ensure that the probe refracted angle used is correct.

Probes a.

Compressional and shear wave probes may be single or combined double (twin) crystal types of test frequency 2 !6MHz. In addition to the requirements in Clause 3.5a. the compressional transducer area is to be not less than 100 square mm and the shear transducer area not less than 70 square mm. The weld preparation and material thickness are to be taken into account when selecting the shear wave probe angle; it is also to be noted that a beam incident on a reflecting surface at 30° will undergo mode conversion which may give rise to spurious indications, there will also be a loss of shear wave energy of up to 20dB. The direction of the beam is to be as near to normal to the angle of the weld edge preparation as possible.

b.

The use of various probe refracted angles may be necessary for the assessment of defect type and severity. Beam angles generally suited to different thicknesses of material are given in TABLE 6.1. PROBE REFRACTED ANGLE

PROBE FEATURE

MATERIAL THICKNESS

Single or combined double

6mm!15mm

70° !80° 60° !70° °!

12mm!35mm

Single or combined double and - -

°

45°

35mm!60mm Over 60mm

TABLE 6.1 BEAM ANGLES

c.

A ‘T-type’ probe is one that is referenced to its half-skip distance in terms of plate material thickness ‘T’ in preference to the probe angle(eg 1T probe = 45° ). The use of T-type probes offers immediate advantages in this half-skip distance-material thickness relationship and in the range of refracted angles covered (see TABLE 6.2.) They are therefore suitable for both initial and complementary inspections. PLATE THICKNES S

PROBE REFRACTED ANGLE

12mm up to and including 50mm

56° 20i to 68° 12i (1½T to 2½T)

above 50mm

45° to 56° 20i (1T to 1½T)

TABLE 6.2 USE OF T-TYPE PROBES

6.1


6.3


6.4

6.5

The condition of the probe contact surface of the item to be examined is to be such that satisfactory coupling between the probe and test surface can be maintained. Surfaces are to be free from scale, rust, weld spatter and other foreign matter. The surface condition of the weld is to be such that it does not adversely influence the examination; preparation of the weld surfaces is to be completed consistent with the requirements to carry out effective ultrasonic examination and accurate interpretation. Depending on the profile and surface condition, dressing of the weld area may be necessary even when probe contact is only to be made with parent material.

Calibration a.

The calibration test piece ideally comprises a sample weld that simulates both the geometry and material features of the weld to be examined. In the absence of such a sample a machined test block of the same material and thickness as the item under test can be used, see FIGURE 6.1 and FIGURE 6.2. Calibration targets consist of holes drilled normal to the examining surface or slots placed as shown. The calibration target type and size is to be as specified by the Design Authority who may require hole type targets for particular applications regardless of the thickness to be examined. As differences in the production material may cause attenuation, frequent checking is essential during inspection to ensure the required working sensitivity is maintained.

b.

The use of the Suppressor/Reject control will adversely affect the linearity of the amplifier. Suppression is therefore to be minimal. Should subsequent adjustment of this control be necessary changes in amplitude linearity are to be noted for consideration in defect sizing.

c.

The instrument is to be calibrated to show a corner reflection of 20% FSD from the hole or notch with the probe index placed at full skip distance on the selected test block. When a distance amplitude curve is in use the reflection from the target is to be set to the curve.

d.

Attenuation variation due to beam path length and the material is to be taken into account before assessment of defect severity.


Plate material adjacent to the weld through which the shear wave must pass is to be inspected in accordance with Clauses 4.4a. and 4.5a. and any defective areas recorded.

b.

Shear wave scanning is to be carried out from both sides of the weld on one plate surface. Signal amplitude, location in the weld and probe movement and position are to be taken into consideration in assessment of defect. (1)

Welds up to 12mm thi ck The shear wave scan may be carried out by directing the probe normal to the weld, with the probe index positioned at the optimum distance of twice the probe skip distance from the centre line of weld and by moving the probe in a path parallel with the centre line of weld. The probe may be oscillated as in Clause 6.5b.(2) provided that full weld coverage and defect location is achieved.

6.2


(2)

Welds over 12mm up to and incl udi ng 50mm Shear wave inspection may be carried out in a series of scanning movements parallel with the weld at intervals not exceeding 60% of the transducer diameter or length. Alternatively the probe may be oscillated to and from the weld and progressed along the weld at intervals not exceeding the width or diameter of the tranducer. The probe system is to be directed normal to the weld centre line, preferably by mechanical means.

(3)

Welds gr eater than 50mm Examination is to be considered in two stages. Stage one—scanning is to be carried out as required in Clause 6.5(2). The effectiveness of this scan will be dependent upon the knowledge of the weld preparation detail; provided that it has first been established that this scan will provide for the complete and effective examination of the weld, the first stage scan will suffice. Stage two—this scan is to follow stage one when the effectiveness of stage one scan is in doubt and in all situations where there is insufficient knowledge of the weld geometry. Stage two is to comprise a minimum of three separate scans on each side of the weld using transmitting (Tx) and receiving (Rx) probes in tandem. The probes are to be suitably linked so that the required distance between them for each scan is maintained (see FIGURE 6.3).

(4)

Note:

6.6

For the detection of transverse defects irrespective of the material thickness, direct inspection from the surface of the weld is preferred. Where the necessary surface preparation cannot be achieved, separate transmitting and receiving probes are to be employed in a guided straddle scan, (see FIGURE 6.4 and FIGURE 6.5). The proper angle between the probes is to be maintained by using a probe guide/jig for the purpose. Referring to FIGURE 6.4, determine the optimum angle between the probes for the maximum response from top and bottom slots A and B in the test block. Note the time base position of each slot response andspread to a convenient scale relative to this block thickness. Adjust sensitivity to give a 20% FSD response from slot A (ie at full skip distance). Search sensitivity is to take account of losses due to surface and beam path length.

Records a.

Records of the weld examination are to include the results of the compressional wave examination required by Clause 6.5a. Defect indications that result from the shear wave examination having a reflectivity of 5% FSD and greater are to be recorded in sufficient detail to apply the acceptance standard in DG Ships/G/10000B.

6.3


For both blocks: Thickness T = Weld Thickness to be Examined

FIGURE 6.1 REFERENCE/TEST BLOCKS FOR WELD THICKNESS UP TO AND INCLUDING 38mm

FIGURE 6.2 REFERENCE/TEST BLOCKS FOR WELD THICKNESS GREATER THAN 38mm

6.4


FIGURE 6.3 REFERENCE/TEST BLOCK

6.5


(REFER TO CLAUSE 6.5b.(2)

FIGURE 6.4 REFERENCE/TEST BLOCK FOR WELD STRADDLE SCANNING

FIGURE 6.5 REFERENCE/TEST BLOCK DIAGRAMMATIC SET-UP FOR STRADDLE SCAN

6.6


7.

TEE-BUTT WELDING

7.1

Application a.

Ultrasonic examination is applied to T-butt welds for the detection of defects in the welding, and in the plate in the vicinity of the weld. Defects in the plate may include defects of laminar form, and cracks in the toes of the welding orientated at an angle with the plate surface.

b.

Reference is made to: (1)

(2)

two types of examination: (a)

Complete examination—This requires the use of compressional wave and shear wave techniques;

(b)

Partial examination—This requires the use of compressional wave technique only. This application may be adequate to examine table-web connections of fabricated frames.

signal amplitudes DL and SL, which are defined as follows: DL = Datum Line = 20% FSD from the relevant test block target; SL = Six dB Line = DL minus 6dB of attenuation= 40% FSD from the relevant test block target.

7.2


7.3

The test surface is to be free from loose scale and any loose foreign matter which could interfere with the test. Shot blasted surfaces covered with a thin coating of spray primer are usually satisfactory, but any successive layers of paint must be removed and the test surface lightly disc or belt sanded for reproducible results.

Test Blocks a.

The test block required for partial and or complete examination is as shown in FIGURE 7.1. The test block thickness is to be within ± 10% of the thickness of the T-butt joint member that is under the probe and is used for the examination.

b.

Probes (1)

Note:

Compr essional wave probes are to be combined double type, of test frequency 4 to 6MHz. The transducer area is to be not less than 100 square mm. The transducer size is to conform to Clause 3.5a. This type of probe is subject to varying response with probe orientation and certain types of defect. To obviate this feature the acoustic baffle of the probe is to be positioned as follows: Normal to centre line of weld when plotting weld width. Normal to centre line of weld when plotting defect width. Parallel to centre line of weld when plotting defect length.

(2)

Note:

Shear wave probes are to be single or combined double type, of frequency 2 to 4MHz. The transducer area is to be not less than 70 square mm. The transducer size is to conform to Clause 3.5a. The angle of refraction is to be 45° .

The use of probes with refracted angles greater than 45° will be necessary when the examination method in Clause 7.4a.(2) is used.

7.1


FIGURE 7.1 COMBINATION BLOCK COVERING DIFFERENT WELD AND PLATE THICKNESS

7.2


7.4


7.5

7.7

(1)

using the surface of the continuous member that is remote to the standing leg and scanning with compressional and shear waves. This is the preferred method and it is to be used whenever possible.

(2)

using both surfaces of the standing leg and the surface of the continuous member that supports it and scanning with shear waves only.

Plotting Weld Width a.

7.6

T-butt welds may be examined by:

Prior to the weld search using the preferred method the weld width is to be plotted. Use a compressional wave probe (see Clause b.(1)), and adjust the first bottom echo from adjacent plate material to a convenient height eg 40% FSD. Move the probe slowly towards the weld and mark the weld edge at the probe index position when this echo reduces to 20% FSD, ie 6dB drop. This procedure is to be repeated on both sides of the weld. Plot the weld edges at intervals not exceeding twice the thickness of the plate under the probe.

Calibration a.

Compressional wave probe Obtain DL (Clause 7.1b.) and SL from the relevant test block target, (see FIGURE 7.1). Both signal amplitude lines are to be identifiable on the oscilloscope graticule.

b.

Shear wave probe Note the horizontal displacement of the probe index from the test block target at probe half skip distance.

c.

The time base is to be calibrated to a range equal to the combined thickness of the material and weld under the probe with the probe contact face set at zero when using compressional or shear wave probes.

Search Sensitivity a.

(1)

(2)

7.8

Compr essional wave pr obe The compressional wave search sensitivity is to be established by the method used in Clauses 4.4a.(4) and 4.4a.(5) and by using the attenuator figures obtained in displaying: (a)

a 20% FSD first backwall echo from an undrilled portion of the test block;

(b)

a 20% FSD echo from the test block target;

(c)

a 20% FSD first backwall echo from the plate material adjacent to the weld to be examined.

Shear wave probe The shear wave search sensitivity will be established by displayed DL amplitude from the test block target corner—direct or first bounce depending on the technique to be used, and increasing this signal by the difference in the attenuator figures obtained for operations (a) and (c) in Clause 7.7(1).

Search Scanning a.

Weld search scanning using compressional and shear wave probes is to be a rectilinear scanning pattern with sufficient traverse to ensure complete examination of the weld section and adjacent plate material. Forward progression is not to exceed one transducer width between each traverse. For partial examination the forward progression is to be as required by the Design Authority.

7.3


7.9

Defect Indication Measurement a.

7.10

The length and width of all defect indications of signal amplitude 20% FSD and greater are to be measured using the 6dB-drop method (Clause 7.4a.). The acoustic baffle of the compressional wave probe is to be positioned as required in Clause b.(1) The depth of defect is to be measured relative to the surface of the plate material remote to that under the probe.

Records a.

Defect indications of signal amplitude 20% FSD and greater are to be recorded together with their positions and defect dimensions, in sufficient detail to apply DG Ships/G/10000B.

7.4


8.

OVERLAY CLADDING

8.1

Application a.

8.2


8.3

A cladded calibration test block is to be prepared using materials similar to those used in the item to be examined. The test block base material is to be at least 25mm thick. The metal cladding is to be deposited using the same welding process and procedure to the same thickness and surface finish as the item to be examined. A 3mm diameter flat bottomed hole is to be drilled through the base material so that the bottom of the hole forms a reflecting surface at the interface of the base material with the cladding material.

Sensitivity a.

8.5

The test surface and reflecting surface are to be free from burrs, loose scale, machining or grinding particles or other loose foreign material. Surfaces are to be smooth and sufficiently free from waviness to allow a proper and uniform examination of all areas, at the required sensitivity level.

Calibration/Test Block a.

8.4

The following requirements apply to the ultrasonic examination of the bond between weld deposited overlay cladding and the base material. Specific requirements due to special shapes or manufacturing processes will be given in the appropriate specification or weld procedure.

The instrument is to be calibrated to display a 20% FSD signal from the test block target.

Probes a.

Probes are to be twin crystal compressional wave of test frequency 2!6MHz. They are to comply with the requirements in Clause 3.5a.

8.6

Method of Examination

8.6.1

General

a.

8.6.2

Manually deposited cladding

a.

8.6.3

Manually deposited cladding is to be examined over the entire surface area. Adjacent scans are to be separated by approximately 80% of the probe crystal width to ensure adequate overlap.

Procedure tests

a. 8.6.4

Scanning is to be carried out from the cladding surface and may be performed manually or automatically by moving the probe in a directed path or by moving the material in a directed path with the probe held stationary. Scanning speed is to be uniform and at a rate determined during backwall can be used to obtain a back reflection be increased to show the back reflection and thus assure adequate coupling.

The examination of cladding procedure test samples is to be carried out in accordance with Clause 8.6.2a.

Machine deposited cladding

a.

Machine deposited cladding is to be examined along grid lines spaced at 50mm intervals and normal to the direction of welding. Additionally continuous scanning is to be applied to a width of 50mm from the edges of the perimeter of the cladded area and penetrations. Continuous scanning is also to be applied to an area with a minimum radius of 150mm around any significant defect.

8.1


8.7

Records a.

Defect indications in the cladding are to be compared with the reference standard in Clause 8.4a. for assessment. The position of each defect indication in excess of the reference level is to be noted and explored to determine the area and/or linear dimensions. Records of defect indications are to be sufficiently detailed to apply the acceptance standard in DG Ships/G/10000B.

8.2


9.

BRAZED PIPE JOINTS

9.1

Application a.

The following requirements apply to the ultrasonic examination of capillary brazed joints in piping systems to assess the area of bond between the pipe wall and coupling fitting.

b.

Reference is made to: (1)

I nser t groove—The groove in the fitting socket prepared to contain the brazing alloy.

(2) Land—The portion of the fitting adjacent to and/or between the insert grooves.

9.2


9.3

Probes a.

9.4

The outer surface of the fitting is to be smooth and clean. Spelter, flux, paint or any other material is to be removed to provide a satisfactory surface for the examination.

Probes are to be combined double compressional wave of test frequency 2!6MHz. Selection of probe type will depend on the dimensions of the fitting and the width of lands. In view of the better resolution provided by focused probes on thin materials, their use is recommended where material thickness allows.

Calibration a.

Test pieces are to be typical joint samples or manufactured sections of the same material and geometric configuration as the production items to be examined. The equipment is to be calibrated to display as distinct signals the: (1)

combined pipe and fitting thickness;

(2)

fitting thickness in way of the joint;

(3)

insert groove depth (if applicable).

The signal positions are to be clearly marked on the instrument graticule.

9.5

Sensitivity a.

Sensitivity is to be adjusted to obtain a FSD signal from the combined pipe wall and fitting thickness, ie the bond condition, except for flange joints to which Clause 9.6a.(6) refers. For those couplings where the fitting and pipe wall thicknesses are similar a multiple echo pattern (not less than four) is to be displayed for the zero-bond condition in the test fitting. The amplitude of any one signal is not to exceed FSD. The assessment of the condition of bond or no-bond is to be made with due regard to the complete trace pattern.

9.1


9.6


9.7

(1)

Recording is to proceed in parallel with the examination and to the requirements in Clauses 9.7a. and 9.7b.

(2)

The acoustic barrier of the probe is to be placed parallel to the longitudinal axis of the pipe and clear of the insert groove. Scanning is to be continuous, moving the probe steadily in a circumferential path without reversing until the scan of each division as marked (Clauses 9.7a. and 9.7b.) has been completed.

(3)

Where possible the probe crystal is to be of a size that allows the joint to be fully scanned in a number of passes without overlap. Where only one pass scanning is possible the probe edge is to be held close to the spelter groove edge during the scan.

(4)

Fittings without insert grooves are to be scanned as a single land joint.

(5)

F lange joints may be satisfactorily examined using the inner surface of pipes depending on the size of probe available. The calibration procedure will be similar to that for sleeved joints, ie successive echoes from the pipe wall thickness will indicate zero bond. Bond condition will be indicated by the absence of the pipe wall echoes or by their attenuation. The distance between the pipe inner wall and the outer radius of the flange may be too great to be shown in the display. Search sensitivity is to be set to show three reflections from the zero-bond condition with the amplitude of the first not exceeding FSD. To ensure proper contact with the inner surface of the pipe, shaping of the probe may be necessary. This must be carried out with care to avoid spurious signals and possibly confused interpretation. The recording procedure is to be as for sleeved joints.

(6)

H exagonal type fi ttin gs are to be examined by scanning the centre of each flat. The percentage bond for the joint is to be assessed by averaging the results obtained.

Records a.

The use of tape as a means of recording as the examination proceeds is recommended, but the use of alternative recording methods which can be demonstrated and result in a comparable record are not excluded. Before commencing the examination apply a band of removable adhesive tape to the pipe adjacent to the fitting. Mark the tape to show equal divisions not exceeding 25mm circumferentially in a clockwise direction as viewed from the pipe facing the fitting. Permanently mark the 12 o’clock position on the fitting by etching, and mark the position on the tape. As the examination proceeds the tape is to be marked to show: (1)

the extent and percentage bond as determined by the difference in bond and zero-bond signal amplitudes for each division of each circumferential scan. Typical examples are shown in FIGURE 9.1.

(2)

‘Not Tested’ areas marked NT, ie areas which cannot be examined due to inaccessibility;

(3)

‘No Ultrasonic Penetration’ areas marked NUP, ie areas which cannot be examined due to fitting material characteristics and spurious signals;

(4)

the number of circumferential scans on fittings without insert grooves;

(5)

the relative positions of lands, ie outer, middle, inner, where insert grooves are a joint feature.

9.2


b.

The information recorded on the tape is to be transferred to a permanent record which is required for each joint examined. The percentage bond assessment of each circumferential scan will be the average of the percentage bond figures established for each division. The percentage bond of the joint will be assessed by averaging the percentage figures established for each circumferential scan. The final figure is to be stated to the nearest whole number.

9.3


FIGURE 9.1 TYPICAL CRT DISPLAYS

9.4


10.

PIPES AND TUBES

10.1

Application a.

10.2

Calibration a.

10.3

Probes are to be shear wave and are to meet the requirements in Clause 3.5a. The test frequency selected is to be compatible with the material type and the wall thickness to be examined for the clear resolution of each calibration target under production conditions.


10.5

A convenient length of pipe or tube of the same material and cross sectional dimensions as that to be examined is to contain notch type targets, and is to be used as a calibration standard. For transverse type defects an internal and external notch is to be cut to the dimensions given in Clause 4.6a. except that the notch may extend wholly around the circumference. The notches are to be separated by at least 40mm and located to permit calibration when the probe is positioned between the pipe or tube end and the nearest notch. For longitudinal type defects an internal and external notch is to be cut to the dimensions given in Clause 4.6a. parallel with the axis of the pipe. The notches are to be separated by at least 30mm in a longitudinal direction. Each notch is to be clearly identifiable on the oscilloscope display. The positions of the internal targets are to be marked on the pipe or tube outer surface.

Probes a.

10.4

The following requirements apply to the examination of pipes and tubes for the detection of transverse and longitudinal discontinuities.

Pipes and tubes are to be scanned parallel to the longitudinal axis for the detection of transverse defects, and in a transverse direction for the detection of longitudinal defects by advancing the probes assembly as the pipe or tube is rotated in such a way that the entire volume of the pipe wall is examined. The speed of pipe or tube rotation is to be reasonably uniform and at a rate consistent with the maximum rotational speed of the calibration standard which enables clear and definite resolution of the notch being presented. This speed is not to be exceeded. Scanning may also be performed by rotating the part and automatically indexing the probes assembly so that crystal overlap of at least 10% is obtained on each successive pass. When the immersion method is used the examination conditions are to duplicate the calibration conditions as regards probes assembly alignment and wet or dry tube bore conditions. In general the exclusion of the immersion fluid from the bore improves the reproduction of the examination results. Each pipe is to be continuously scanned.

Records a.

The location extent and signal amplitudes of all indications in excess of the agreed sensitivity level are to be recorded.

10.1


10.2


11.

PIPE OR TUBE WALL THICKNESS MEASUREMENT

11.1

Application a.

11.2


11.3

The requirements in Clauses 5.a. to 5.1b. are to apply.


11.7

Compressional wave probes suitable for the purpose are to be used. These may be single or combined double types. The frequency is to be compatible with the material type and thickness of the pipe or tube to be examined. The probe size selected for the examination of pipes or tubes that are in service, will depend upon the configuration of the pipe or tube and the cross-sectional dimensions.

Calibration a.

11.6

The requirements in Clause 5.a. are to apply.

Probes a.

11.5

The test surfaces are to be free from loose scale, rust and any other foreign matter which could interfere with the examination.

Equipment a.

11.4

The following requirements apply to the examination of pipe or tube to determine wall thickness at the probe contact position. The method will not detect pin holes.

Each pipe is to be placed on suitable rollers and rotated as the examination proceeds. Each end is to be examined by turning the pipe through one full revolution with the probe at the end; additional scans are then to be made at intervals not exceeding 900mm along the entire length of the pipe unless otherwise specified. In-service pipes and tubes are to be examined in accordance with the applicable requirements of survey with particular attention to inner and outer radii of bends. The use of a probe holder to hold the probe normal to the pipe surface during in-service examinations is recommended. In all cases, areas where the wall thickness approaches minimum tolerance are to be subjected to a complete search to determine the extent.

Records a.

Records are to provide for the positive identification of the pipe or tube, material type, coverage given and the location of areas where the wall thickness approaches minimum tolerance or otherwise as specified in the Contract Documents.

11.1


11.2


12. 12.1

FORGINGS—INCLUDING FORGED, EXTRUDED AND WROUGHT BARS

Application a.

12.2


12.3

The wide variety of forgings in respect of material type, size and geometry required by MOD(PE) prevents the formulation of rigid ultrasonic examination procedures for general application. Specific procedures must take into account the material type and grain size, material attenuation factors, method of manufacture, and the type, location and probable distribution of defects likely to be encountered. In the examination of non-ferrous bar, detection of sub-surface defects is limited by the relationship between material grain size (approx diameter), the wavelength of the ultrasonic energy and the size of the smallest detectable defect, since the diameter of the smallest detectable defect will equate to one wavelength of the energy, and reduction in ultrasonic frequency to overcome grain size problems will mean an increase in the size (width) of the smallest detectable defect. Ultrasonic test of non-ferrous bar may only be practical where attenuation through the material does not preclude the use of reflection techniques, and may only be meaningfully used for quality purposes where the maximum width of acceptable defect is not less than those related to the diameter of the horizontal target holes in FIGURE 12.1. Bars may contain defects of width less than the minimum acceptance standard which may not be detected and which could extend throughout the length of the bar. Diagnosis of defect indications in thick sections demands an accurate knowledge of probe characteristics. For the examination of steel forgings, excluding austenitic, BS 4124 Part 1 is to apply. For forgings to which BS 4124 Part 1 cannot be applied, and extruded and wrought bars, the following clauses apply.

The condition of the test surface and the reflecting surface is not to cause interference with the examination. Surfaces are to be free of loose scale, paint or other foreign matter. Rough machined surfaces are to be reduced using a broad-nosed tool to produce a regular smooth surface to avoid spurious indications and excessive wear of the probe face.

Probes a.

Probe selection will depend on the geometry of the item to be examined, material type and grain size, and the area of probe contact surface. The best near surface resolution will be obtained using combined double compressional wave probe and this characteristic is of value in the examination of areas subject to subsequent machining. Generally the probe test frequency will be in the range 2!6MHz but a lower frequency may be necessary to overcome the effects of material large grain structure and long beam path length. Shear wave probe techniques are to be used where specified. On bored items where the bore is inaccessible for examination with a compressional probe an appropriate shear wave technique is to be used. Shear wave is also to be used to cover areas where the shape of the item prevents comprehensive examination by compressional wave.

12.1


T = Thickness to be tested ± 10% {= The block may be cut to this line to facilitate drilling where a single block is

required for use. Alternatively a number of separate reference blocks may be employed. Material Steel

Phosphor Bronze

Hiduron

Thickness to be examined (mm)

Dia of FBH (mm)

Dia of Horizontal hole (mm)

Up to and incl 25 Over 25 to 60 (incl) Over 60 to 100 (incl) Over 100 to 150 (incl) Over 150

1.5 2.5 3.5 4.5 6.0

!

Up to and incl 50 Over 50 to 70 (incl) Over 70 to 100 (incl) Over 100

1.5 2.5 3.0 4.0

!

Up to and incl 50 Over 50 to 100 (incl) Over 100

1.5 2.5 3.0

1.5 2.5 3.0

NOTES 1.

The flat bottom of the holes is to be parallel to the entrant surface.

2.

The reference standard is to be wide enough to permit sound transmission to the flat bottom holes without side effects.

3.

The reference standard material is to be ultrasonically free from obvious defects and similar to the material being tested. The surface finish is to be comparable to the test surface and of similar contour.

4.

The test frequency is to be the same as the calibration frequency.

5.

The equipment is to be set to show a minimum echo of 20% full screen deflection from each hole within the thickness to be inspected.

6.

Where shear wave examination of rod or bar is stipulated a reference standard containing a hole drilled on the horizontal axis will be required. The first direct corner reflection from the hole at the end face of the block is to be used in setting sensitivity. FIGURE 12.1 REFERENCE STANDARD

12.2


12.4

Calibration a.

12.5


12.6

The reference standard FIGURE 12.1 is to apply. The attenuator figures obtained from the adjustment of sensitivity to give 20% FSD signal amplitude from the backwall of the reference standard, each of the flat bottomed holes and the backwall from the material under examination are to be recorded and used to derive the minimum search sensitivity by the method of Clause 4.4a.(4), 4.4a.(5), and 4.4a.(6). Sensitivity is to take account of local attenuation factors and the depth of defect in the material when defect is evident.

Wherever possible forgings are to be examined from surfaces so arranged that three major places are covered. The technique is to assure the detection of defects that are parallel to and normal to the principal axes. Defect areas and suspect areas disclosed under these conditions are to be further evaluated from the surface opposite that used for their initial detection. Unless otherwise specified in the Contract Documents the search unit is to be moved in parallel paths. Each path is to overlap the previous and adjacent path by 10% of the width of the transducer. This procedure is to be repeated on all examining surfaces. Items of irregular section may require the preparation of a series of examination techniques for effective coverage.

Records a.

The size and location of all defect indications causing reflectivity of 20% FSD and greater are to be recorded and marked on the item as the examination progresses. Additionally in the examination of non-ferrous bars or rods the location of indications causing reflectivity of 5% !20% FSD are to be recorded. Records are to be sufficiently detailed to apply the relevant acceptance standard or as defined in the Contract Documents.

12.3


12.4


13.

CASTINGS

13.1

Application a.

13.2

Surface Condition a.

13.3

The choice of probes will be influenced by the casting material, geometry and the type of defects to be detected. The use of both compressional wave and shear wave probes may be necessary in defect assessment (Clause 12.3a. will apply).

Calibration a.

13.5

The condition of the test surface and the reflecting surface is to permit effective ultrasonic examination using the approved procedure. Shot blasted surfaces will improve probe coupling efficiency. Rough machined castings may require further preparation to provide a flat smooth surface to avoid spurious signals and excessive wear of the probe face.

Probes a.

13.4

The application of ultrasonic methods to the examination of ferrous and non-ferrous castings requires the use of techniques that will enable defect assessment for the proper application of the acceptance standard. It is to be recognised that no single technique will suit all applications and also that the casting material type and surface condition may inhibit useful and economical application. The requirement to discriminate between defect types and their varying degrees of severity in respect of area and volume etc and their position in the material will demand exacting techniques, and in view of the apparent difficulties the MOD(PE) will require the validity of ultrasonic techniques to be confirmed by radiographic examination of selected areas of castings where both examination methods can be usefully employed.

Reference blocks as required are to be prepared from sound material and to conform to the requirements in Clause 3.6a.


It will first be necessary to establish that the material grain structure and surface finish permit adequate ultrasonic transmission for the proper examination of the area required. Each area will need to be checked for this purpose by observing the backwall response using a compressional wave probe or a corner reflection using a shear wave probe.

Note:

b.

In the ‘as-cast’ condition the grain size of the material is large. Where the grain diameter approaches ultrasonic wavelength high attenuation will occur. In the heat treated condition the grain structure is refined with a subsequent reduction of attenuation.

The compressional wave search sensitivity level is to be as high as possible and consistent with acceptable levels of reflections from material grain. Evidence of defect is to be cause for adjustment of sensitivity before attempting assessment, by taking account of its position below the surface and attenuation effects, and local probe transfer losses. Assessment of defect severity may necessarily combine amplitude and attenuation methods for different defect types. Areas that cause the backwall echo to reduce to 20% FSD and less with no evidence of reflecting defect are, after a check of local surface condition and coupling, to be marked on the casting as ‘attenuating defect areas’ as the examination progresses for subsequent inclusion in the record of test.

13.1


13.6

Assessment of Defects a.

The assessment of defect types and their severity as required for the proper application of the acceptance standard DG Ships/PS/9010B may necessarily require radiographic examination of the areas concerned to confirm or determine their acceptability.

13.2


14.

SAFETY a.

All equipment involving the use of main electrical supply is to conform to the relevant statutory requirements and safety regulations.

b.

All examinations referred to in this NES are to be carried out with due regard to the applicable statutory requirements, safety regulations, and Codes of Practice.

14.1


14.2


ANNEX A. RELATED DOCUMENTS A.1

Reference is made to: Referred to in Clause BS 2704

Specification for calibration blocks for use in flaw detection

BS 3683 (Part 4)

Glossary of terms used in non-destructive testing: Pt 4—Ultrasonic flaw detection

BS 3923 (Part 3)

Method for ultrasonic examination of welds

3.5a.

BS 4124 (Part 1)

Non-destructive testing of steel forgings

12.1a.

BS 4331(Parts 1 & 3)

Method for assessing the performance characteristics of ultrasonic flaw detection equipment

DG Ships 86C (*NES 793)

Ultrasonic Acceptance Standards for QT28, QT35 and Navy Q1 steels

1.a.

DG Ships 137 (*NES 736 Part 4)

Thickness measurement of steel plates

5.2a.

DG Ships/PS/5108

Non-destructive Examination Requirements

SCOPE 4.

DG Ships/PS/9010B (*NES 745)

Classification, Inspection Requirements and Acceptance Standards for Steel and Copper-Base Alloy Castings

1.a., 13.6a.

DG Ships/G/10000B (*NES 773)

Minimum Acceptance Standards for Welds in HM Ships and Submarines

1.a., 6.6a., 7.10a., 8.7a.

Note:

3.4a., 3.5a. B.1

3.4a., 3.5a.

*In course of preparation. When published will supersede stated documents.

A.1

ANNEX A.


ANNEX A.

A.2


ANNEX B. DEFINITIONS AND ABBREVIATIONS B.1

BS 3683 (Part 4) is to apply to the terms in this NES. Design Authority

This term as used refers to that section or group within the MOD that has overall responsibility for the material, item, structure, system or vessel concerned.

Examining Authority

This term as used refers to the Company, Organization, Establishment or Naval Base that carries out the ultrasonic examinations within the scope of this NES.

B.1

ANNEX B.


ANNEX B.

B.2


ANNEX C. PROCUREMENT CHECK LIST TITLE ....................... REFERENCE.....................

Notes: 1.

This Check List is to ensure that certain aspects of this Naval Engineering Standard are consulted when preparing a Statement of Technical Requirements for a particular application.

2..

Clauses where a reference for an o tion is to be used or where s ecific data is to be added are included in the Check List.

3.

Each item is to be marked either

CHECK No

!

= included

NA

= not applicable

CHECK

CLAUSE No

1

The extent to which ultrasonic examination is required is specified in the Contract Documents.

SCOPE 3.

2

The Standards for acceptance of defect indications detected by ultrasonic examination are to be as specified in the Contract Documents.

1.a.

3

Acceptance inspection is to be performed on an item in the final surface condition and the final heat treated condition unless otherwise specified in the Contract Documents.

2.b.

4

The extent of coverage of thickness gauging is to be specified in the Contract Documents.

5.2a.

5

Records are to provide for the positive identification of the pipe or tube, material type, coverage given and the location of areas where the wall thickness approaches minimum tolerance, unless otherwise specified in the Contract Documents.

11.7a.

6

The search unit is to be moved in parallel paths unless otherwise specified in the Contract Documents.

12.5a.

7

Records are to be sufficiently detailed to apply the relevant acceptance standard unless otherwise specified in the Contract Documents.

12.6a.

C.1

! or NA

ANNEX C.


ANNEX C.

C.2


ALPHABETICAL INDEX

C Calibration brazed pipe joints, 9.1 butt welding, 6.2 castings, 13.1 forgings, 12.2 overlay cladding, 8.1 pipe and tube, 10.1 pipe or tube wall thickness, 11.1 plate material, 4.1 plate thickness measurement, 5.1 sensitivity, 3.4 Tee-butt weld ing, 7.3 C astings, 13.1 Cladding, 8.1 Compressional wave inspection, 4.1

D Defect indication measurement, 7.4 D efinitions, 7.1, 9.1, B .1 D esign Authority, B .1

E Equipment, 3.2, 5.1, 11.1 Equipment performance characteristics, 3.3 Eq uipment q ualification, 3.4 Examination methods brazed pipe joints, 9.2 butt welding, 6.2 castings, 13.1 forgings, 12.2 general, 3.5 overlay cladding, 8.1 pipe or tube wa ll thickness measurement, 11.1 pipes and tubes, 10.1 plate material, 4.2 shear wave, 4.2 Tee-butt weld ing, 7.1 Examining Authority, B.1

F Forgings, 12.1

I Inspectio n, 2.1, 3.1, 3.2, 3.3, 3.4, 3.5

INDEX.1

INDEX


P Personnel requirements, 3.1 Pipe joints, brazed, 9.1 Pipe or tube wall thickness measurement, 11.1 Pipes a nd t ubes, 10.1 Plate material, 4.1 Plate thickness gauging, 5.1 measurement, 5.1 Plotting weld width, 7.3 Probes brazed pipe joints, 9.1 butt welding, 6.1 castings, 13.1 forgings, 12.1 general, 3.3 overlay cladding, 8.1 pipe or tube wall thickness measurement, 11.1 pipes a nd tubes, 10.1 Tee-butt weld ing, 7.1

R Records brazed pipe joints, 9.2, 9.3 butt welding, 6.3 forgings, 12.3 overlay cladding, 8.2 pipe or tube wall thickness measurement, 11.1 pipes a nd tubes, 10.1 plate material, 4.3 Tee-butt weld ing, 7.4

S Safety, 14.1 Search scanning, 7.4 Search sensitivity, 7.3 Standards, acceptance, 1.1 Surface finish, 3.5 Surface preparation brazed pipe joints, 9.1 butt welding, 6.2 castings, 13.1 forgings, 12.1 general, 3.3 overlay cladding, 8.1 pipe or tube wall thickness measurement, 11.1 plate material, 4.1 plate thickness measurement, 5.1 Tee-butt weld ing, 7.1

T Test blo cks, 3.4, 4.1, 5.1, 7.1 Test pro cedu re, 3.1

INDEX

INDEX.2


W Welding butt, 6.1 Tee-but t, 7.1

INDEX.3

INDEX


INDEX

INDEX.4

Inside Rear Cover

NES 729 Part 5 Requirements for Non-Destructive Examination Methods

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