Magnetic Praticle Inspection Procedure [PDF]

Zitiervorschau

MAGNETIC PRACTICLE INSPECTION PROCEDURE

TUNISIA - SFAX: Road Mahdia Km 1, N°84 Street Mohamed Ikbal, P.O. Box: 89A 3099 Sfax Tunisia, Tel: +216 74232032 / Fax: +216 74234717.

- TUNIS: 13 Street Michael Noaima 2080 Arian Tunisia, Tel: +216 71 820205, Fax: 71 820128. - GABES: Street Environment Chenini Nahal 6041,Tel / Fax: +216 75229440. LIBYA: BECA Libya For Inspection, Testing And Analysis, Street 16 off 11 June Road Nearby Ben Zahra Mosque Souk Al Joumaa Tripoli Libya,Tel / Fax: +218 (0) 213501973.

ABU DHABI: BECA Abu Dhabi, Branch UAE, P.O. Box: 129865 Abu Dhabi UAE, Tel: +971(0) 25102400, Fax: +971 (0) 25589961.

TECHNICAL DEPARTEMENT

GABON: BECA Securale De Gabon, Boulevard Léon MBA Quartier Littoral face central SEEG B.P. N°1701

BECA COMPANY

Port – Gentil Gabon, Tel / Fax: +241 01569527. CONGO : Luanda Pointe Noire – Congo Tel : +242069069213 Email:[email protected]

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 2 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

TABLE OF CONTENTS

1. SCOPE..................................................................................................................................................................... 4 2. REFERENCES CODES & SPECIFICATIONS............................................................................................................. 4 3. PERSONNEL .......................................................................................................................................................... 4 4. MAGNETIZING TECHNIQUES ............................................................................................................................... 4 5. CONSUMABLES..................................................................................................................................................... 4 6. VIEWING CONSITIONS.......................................................................................................................................... 5 7. SAFETY PRECAUTIONS ......................................................................................................................................... 5 8. METHODOLOGY ................................................................................................................................................... 5 9. INTERPRETATION OF RESULTS ........................................................................................................................... 7 10. ACCEPTANCE CRITERIA ...................................................................................................................................... 7 11. RECORDS .............................................................................................................................................................. 7

ATTACHMENT: Appendix 1: Magnetic particle examination report.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 3 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

1. SCOPE This document provides the procedure to be employed for the magnetic particle examination of ferromagnetic welds and adjacent base materials using either magnetic or current flow technique. It is intended for use on work governed by the codes listed in paragraph 2.0 of this procedure

2. REFERENCES       

API 1104 Standard for Welding pipelines and related facilities ASME B31.8 Gas Transmission and Distribution Piping System ASME B31.3: Process Piping ASME Code Section V: Non destructive Methods Of Examination ASME Code Section VIII: Design and Fabrication of Pressure Vessels API 650: Welded tanks for oil storage Specifications client

3. Personnel Personnel having I or II level according to ASNT SNT-TC-1A or COTEND are authorized to perform Magnetic particle Testing. Personnel having II level according to ASNT SNT-TC-1A or COTEND are authorized to make the interpretation of results.

4. Magnetizing techniques The equipment provided by the company for use in the performance of magnetic particle testing shall normally be of the portable tube. Magnetic fields shall be induced into materials under test by one of the following methods:  Magnetic flow technique  Current flow technique Only calibrated equipment shall be used and calibration certificate shall be submitted for review and approval.

5. Consumables 5.1 Contrast paints To improve the efficiency of the process, the specimen shall be given a preliminary coat of white paint to present a high contrast background to the black magnetic ink delineating the indication. The contrast paint shall be a type which is quickly drying and can be applied to give a thin even coat. 1. 5.2 Inks and powders The concentration of all inks and powders, provided by the company, for the proposes of magnetic particle inspection shall meet the requirements of several codes below. Inks and powders shall be supplied by recognized agents. The preferred and any alternative brand will be stipulated on the appropriate technique sheet. Consumable materials shall be supported by data sheet & validity certificates.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 4 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

6. Viewing conditions The area to be inspected shall be evenly illuminated by daylight or artificial light. The level of the intensity of the light shall not be less than 500lux. This can be achieved by using a tungsten filament lamp of 100 watts of a distance of approximately 0.2m.

7. Safety precautions In accordance with the control of substances hazardous to health (COSHH) all technicians employed to carry out magnetic particle testing shall be familiar with data sheet that fully describe the nature of the hazard associated with the flammability and toxicity of solvent based materials.

8. Methodology: A /Techniques For all magnetic particle inspection performed by the company a technique sheet shall supplement this procedure. The technique sheet shall define the parameters that govern the test and shall stipulate the acceptance criteria. The company’s standard technique sheet is shown. B/ Equipment B.1 Magnetic flow Where the component or item being tested closes the magnetizing circuit of an electromagnet or permanent magnet. a/ Magnetizing Yokes (AC electromagnet):

This method shall be the preffered method where the use of portable hand magnets is required. All Yokes shall be supplied with articulated pole pieces that can provide intimate contact with the surface of the item or component being tested. The magnetizing force of each yoke shall be demonstrated by determining the minimum lifting power that shall exceed 4.5 kg at the maximum pole spacing at which full surface contact can be made with the test load. Each yoke shall be uniquely identified. The function testing of magnetic yokes shall be carried out before use or daily inspection if the magnet is in constant use. The function test shall be carried out by lifting a suitable test weight with the yoke. The acceptable performance of the function test shall be recorded on the record sheet. Any yoke that can not lift the test weight shall be immediately withdrawn from service. The function test of electromagnets shall also include visual inspection of the articulated joints to ensure a free movement according to the original design of the magnet. b/ Permanent magnetic:

The use of permanent magnet shall not be normally preferred to the use of AC yokes. However, in certain operating condition the use of the electromagnets may prove impracticable. The magnetizing force of permanent magnets shall be demonstrated by determining their minimum lifting power. Permanent magnets shall be able to lift by magnetic attraction alone 18 kg. Additionally such magnets shall exhibit a pull-off force (the force needed to be applied to one pole piece to break down its adhesion to the test surface) of at least 9kg. This shall be carried out using a spring balance of the plate. The ability of the magnet to meet this requirement shall be demonstrated immediately before use. The successful completion of the lifting test shall be recorded on the format given. B.2 Test weights Test weights shall be uniquely identified and certified to provide objective evidence of their true weights

B.3 Current flow This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 5 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

When current form external power source passes between two contacts, generally affected by the means of hand help probes. This method shall be used for the inspection of large areas and welds. The equipment shall only be used together with a specific techniques provided by the company and approved by its client. The technique sheet shall specify the equipment type and current values according to approved inspection codes. C /Temperature limitation a) Wet magnetic particle examination

The magnetic particle examination shall be the preferred method and shall be carried out in all instances unless the surface temperature of the object being tested exceeds 57°C. b) Dry powder particle examination

The dry powder method of inspection shall be used in all cases where surface temperatures of the item being tested exceed 57°C. the selection of the type of powder shall depend of the surface temperature of the item to be examined and shall normally be defined by the maximum working temperature of the powder as described by the manufacture of the powder. D /Surface condition Visual inspection shall be carried out before commencement of magnetic particle inspection. The technician performing magnetic particle inspection shall ensure that the surfaces to be inspected are free from all extraneous matter such us paint, grease, weld spatter and accumulation of dust, dirt or water. The surface of the test area shall be free from rust. During the testing of welds or other areas that have been mechanically worked or finished the technician shall make special notice of grinding marks or any abrupt changes of shape or section that may complicate the interpretation of inspection results. E/ Background paint The application of the contrast paint shall be made on the surface that free from grease. If the paint shows signs of lifting due to traces of oil, this shall be overcome by rubbing the first coat into the surface with a dry cloth and then applied the second coat. F /Sensitivity Adequate sensitivity shall be demonstrated by using magnetic flux indicators of type either a, b or c below: a) Burmah Castrol Strips Type 1 Brass Finish b) Berthold Penetrameter used at setting number 2 c) Burmah Castrol Strips Type 2 Silver Finish Magnetic flux indicator shall not be employed when permanent magnets are used to induce the magnetic field. With the indicators fixed or held in position on the surface being tested the magnetizing field shall be applied across the axis of the indicator with indicator positioned centrally between the poles of the magnet. After allowing five seconds for particle migration, with magnetic field applied, the indicator should show a clearly defined congregation of magnetic particles indication the artificial defect. For a satisfactory indication the artificial defect. For a satisfactory indication the test shall be repeated with the magnetizing force applied at 90° to the axis of indicator. G/ Sequence of operation

 All surfaces shall be visually inspected (before commencement of testing) to ensure that they are free from any foreign material such as grease, paint etc.  If required white background paint shall be applied to the test surface.  The magnetizing field shall then be applied to the test area.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 6 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

 The magnetic ink or powder shall be sprayed onto the area being tested while the magnetic field is applied.  The surface being tested shall be visually inspected during the time that magnetizing force is applied in two perpendicular directions at least  The position of any defect indications seen shall be identified compared with a datum point marked on the test piece.  The magnetic field shall be withdrawn.  Post inspection cleaning shall normally be associated with magnetic particle inspection to remove the residue of testing. Due to other consideration, i.e. contractual responsibilities, the permanent protection of structural and piping systems, detailed method of cleaning are considered outside the scope of this procedure. However, all technicians are instructed to ensure that acceptable standards of housekeeping are maintained.  An inspection report shall than be compiled and submitted. H/ Non relevant indications

Any indication believed to be non-relevant, such as grinding marks that may cause indications shall be regarded as unacceptable until the indication has been eliminated by surface conditioning or by further satisfactory evaluation. I/ De-magnetizing

If required J/Marking of flaw indications The marking of flaw indications on the tested component shall be considered necessary as the resultant indication found at the time of inspection can not be considered permanent. The position of flows shall be marked on the tested component by a method that will not affect the use of the component or prejudice any subsequent testing .Magnetizing units for electromagnetic yokes shall be capable of producing alternating current, direct current, or both. This procedure is also applicable for permanent magnetizing technique

9. Interpretation of results: Adequate illumination shall be provided to ensure proper evaluation. Indications will be revealed by retention of the magnetic particles. All indications are not necessarily defects however, since excessive surface roughness and magnetic permeability variations (such as at the edge of heat affected zones) may produce similar indications which are not relevant. Defective conditions are actual or real openings in the surfaces of the material such as cracks, laps, porosity, incomplete fusion… etc, any interruption in the normal physical structure of the material (weld or base metal) which will cause detectable magnetic particle indications.

10. Acceptance criteria: The acceptance criteria shall be according to the required standard API 650.

11. Records: As a minimum, the following information shall be recorded: a) Job number. b) Weld or area examined.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 7 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

c) Weld joint or part identification d) Date of examination e) Examination material used f) Examination results g) Client

h) NDT operations name and certification level.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 8 of 9

Revision 6

MAGNETIC PRACTICLE INSPECTION PROCEDURE

T.P – N.D.T 003

Appendix 1: Magnetic particle examination report.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

T.P – N.D.T – 003

Page 9 of 9

Revision 6