POS-PT-01 Rev.01

POSCO E&C VIET NAM

LIQUID PENETRANT EXAMINATION PROCEDURE


Document No.: POS-PT-01 Rev.001

POSCO E&C VIETNAM CLIENT

PREPARED BY REVIEWED BY APPROVED BY

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CHANGE OF RECORD:

Rev. Date Change of Item

01 01/12/2012 Issue new document

CONTENT

1. INTRODUCTION..................................................................................................................3

2. SCOPE.................................................................................................................................3

3. REFERENCES.....................................................................................................................3

4. PERSONNEL.......................................................................................................................3

5. PENETRANT MATERIALS..................................................................................................4

6. SURFACE CONDITIONING PRIOR TO PENETRANT EXAMINATION AND PRECLEANING....................................................................................................................4

7. DRYING AFTER PREPARATION........................................................................................5

8. PROCEDURE/TECHNIQUE.................................................................................................5

9. EXAMINATION.....................................................................................................................6

10. EVALUATION......................................................................................................................8

11. ACCEPTANCE CRITERIA...................................................................................................8

12. DOCUMENTATION............................................................................................................10

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1. INTRODUCTION

This procedure is developed to cover the general requirements for Liquid Penetrant

Examination

SCOPE

This procedure defines the conditions and requirements of performing the Liquid

Penetrant Examination in accordance with the ASTM STANDARD TEST METHOD

SE 165.

- This procedure uses Visible (Type II), Solvent Removable (Method C) Penetrant to

detect discontinuities that are open to the surface such as crack, laps, seam cold

shut, laminations, through leaks, or lack fusion and are applicable to in – process,

final, and maintenance examination.

- The examination can be effectively used in the examination of nonporous, metallic

materials, such as glazed or full densified ceramics, certain nonporous plastics, and

glass.

2. REFERENCES

- AWS D1.1 Structural Welding Code Steel 2010 Edition.

- ASTM SE 165 Standard Test Method for Liquid Penetrant Examination.

- ASNT Recommended Practice for Personnel Qualification and Certification in

NonDestructive Testing No. SNT-TC-1A 2006

3. PERSONNEL

Personnel performing Liquid Penetrant Examination shall be qualified and certified

Individuals who perform Liquid Penetrant Examination shall be qualified for:

- NDT Level II.

- Interpretation of results shall be done by Level II or higher.

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Certification of Level I and Level II individuals shall be performed by an ASNT NDT

Level III or who has the education, training, experience, and has successfully

passed the written examinations described in AVN-IND-P09.

4. PENETRANT MATERIALS

- The penetrant materials used in this procedure shall include:

Visible Solvent removable penetrant

Solvent remover

Non aqueous developer

- These materials shall be contained in compressed cans ready for aerosol spraying

applies.

- Types of consumable materials to be used are as follow:

Product of KYUNGDO (KOREA):

- KYUNGDO Dyecheck penetrant P2 (Visible Red Waterwashable and solven

removable, non Corrosive). This type can be used on the surface temperature up to

570C)

- KYUNGDO Developer D4 (Non Aqueous Developer, non Corrosive). This type can

be used on the surface temperature up to 570C)

- KYUNGDO R1-3 Remover (non Corrosive, non sulphurous and non halogenic).

This type can be used on the surface temperature up to 570 )

- Or ther chemical equivalent

5. SURFACE CONDITIONING PRIOR TO PENETRANT EXAMINATION AND

PRECLEANING

- In general, satisfactory results maybe obtained on the surfaces in the as-welded,

as-rolled, as-cast, or as-forged conditions.

- When only loose surface residuals are present, these may be removed by wiping

with clean lint-free cloths. However, precleaning of metals to remove processing

residuals such as oil, graphite, scale, insulating materials, coatings, and so forth,

shall be done using cleaning solvents, vapor degreasing or chemical removing

processes.

- Surface conditioning by grinding, machining, polishing or etching shall follow shot,

sand, grit or vapor blasting to remove the peened skin and when penetrant

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entrapment in surface irregularities might mask the indications of unacceptable

discontinuities or otherwise interfere with the effectiveness of the examination.

- For metals, unless otherwise specified, etching shall be performed when evidence

exist that previous cleaning, surface treatments or service usage have produced a

surface condition that degreasant the effectiveness of penetrant examination.

- All parts or areas of parts to be examined and all adjacent areas within at least

25mm shall be dry and free of rust, scale, welding, flux, weld spatter, grease, paint,

oily films, dirt, and so forth, that might interfere with the penetrant process, before

the penetrant is applied.

6. DRYING AFTER PREPARATION

- After cleaning, drying of the surfaces to be examined shall be accomplished by

normal evaporation or with forced hot or cold air.

- Minimum 01-minute duration shall be required to ensure that the cleaning solution

has evaporated prior to application of the penetrant.

7. PROCEDURE/TECHNIQUE

8.1 Techniques

- A color contrast (visible) penetrant shall be used with solvent removable process.

8.2. Techniques for standard temperatures

- The temperature of the penetrant and the surface of the part to be processed

shall not be below +50C nor above +520C throughout the examination period.

- Local heating or cooling is permitted provided the part temperature remains in

the range of +50C to +520C during examination.

8.3. Techniques for nonstandard temperatures

8.3.1 Temperature less than 50C: If it is desired to qualify a liquid penetrant

examination procedure at a temperature of less than 50C, the proposed

procedure shall be applied to block “B” after the block and all materials

have been cooled and held at the proposed examination temperature until

the comparison is completed. A standard procedure which has previously

been demonstrated as suitable for use shall be applied to block “A” in the

50C to 520C temperature range. The indications of crack shall be compared

between blocks “A” and “B”. If indications obtained under the proposed

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conditions on block “B” are essentially the same as obtained on block “A”

during examination at 50C to 520C, the proposed procedure shall be

considered qualified for use. A procedure qualified at a temperature lower

than 50C shall be qualified from that temperature to 50C.

8.3.2 Temperature greater than 520C: If the proposed temperature for the

examination is above 520C, block “B” shall be held at this temperature

throughout the examination. The indications of crack shall be compared as

described in 8.3.1 while block “B” is at the proposed temperature and block

“A” is at the 50C to 520C temperature range.

To qualify a procedure for temperatures above 520C, the upper and lower

temperature limits shall be established and the procedure qualified at these

temperatures.

8.4. Technique restrictions

Intermixing of penetrant materials from different families or different manufacturers is not permitted.

8. EXAMINATION

9.1 Penetrant application

- The penetrant shall be applied by spraying as described below:

Thoroughly shake the aerosol can for 10-15 seconds

Apply the penetrant to the dry surface to be examined such that the entire part of area under examination area completely covered with penetrant.

9.2. Penetration time (Dwell time)

- Penetration time is critical and shall be not less than recommended minimum dwell time as shown in Table T-672 of ASME Section V.

-

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9.3. Excess penetrant removal

- After the specified penetration time elapsed, excess penetrant shall be removed by wiping with a cloth or absorbent paper, repeating the operation until most traces of penetrant have been removed.

- The remaining traces shall be removed by lightly wiping the surface

with a cloth or absorbent paper moistened with solvent.

- To minimize removal of penetrant from discontinuities, care shall be taken to avoid the use of excess solvent.

- Flushing the surface with solvent, following the application of penetrant and prior to developing, is prohibited.

9.4. Drying after excess penetrant removal

- The surfaces may be dried by normal evaporation, blotting, wiping, or forced air.

9.5. Developing

- After the excess penetrant has been removed and the surface has been dry, the developer shall be applied by spraying in such a manner as to ensure complete part coverage with a thin, even film of developer. The maximum time interval between after removal of penetrant and application developer shall be 2 minutes.

- Developing time for final interpretation begins as soon as a wet developer coating is dry.

- The minimum developing time shall be not less than 10 minutes.

- The maximum developing time shall not more than 01 hour.

9.6. Interpretation

- Final interpretation: final interpretation shall be made within 10 to 60 min after the requirements of developing time are satisfied. If bleed-out does not alter the examination results, longer periods are permitted. If the surface to be examined is large enough to preclude complete examination within the prescribed or established time, the examination shall be performed in increments.

- Characterizing indication(s): the type of discontinuities is difficult to evaluate if the penetrant diffuses excessively into the developer. If this condition occurs, close observation of the formation of indications during application of the developer may assist in characterizing and determining the extent of the indication(s)

- Color contrast penetrants: With a color contrast penetrant, the developer forms a reasonably uniform white coating. Surface discontinuities are indicated by

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bleed-out of the penetrant which is normally a deep red color that stains the developer. Indications with a light pink color may indicate excessive cleaning. Inadequate cleaning may leave an excessive background making interpretation difficult. A minimum light intensity of 100 fc (1000 Lx) is required to ensure adequate sensitivity during the examination and evaluation of indications.

9.7. Post-examination cleaning

- When post-examination cleaning is required by the procedure, it should be conducted as soon as practical using a process that does not adversely affect the part.

9. EVALUATION

- Discontinuities at the surface will be indicated by bleed-out of penetrant; however, localized surface irregularities due to machining marks or other surface conditions may produce false indications

- Broad areas of pigmentation which could mask indications of discontinuities are unacceptable, and such areas shall be unacceptable, and such areas shall be cleaned and re-examined.

- Any questionable or doubtful indications shall be reexamined to determine whether or not they are relevant.

- Unless otherwise specified, it is normal practice to interpret and evaluate the discontinuity based on the size of the indication.

10. ACCEPTANCE CRITERIA

All indications shall be evaluated in term of the acceptance standard which is in conformance with Section 6, Part C, of AWS D1.1, whichever is applicable. Refer to Table 6.1.

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11.DOCUMENTATION

Liquid penetrant Examination report will be generated and will contain the following minimum information as applicable:

a) Clients Name and Details of Item Inspected

b) Report Reference Number and Date and time of examination

c) Material Type, Thickness, Temperature and Surface Preparation

d) Cleaning Method

e) Method and type of Chemical used ( Number. or Letter designation )

f) Dwell Time

g) Acceptance Criteria and Evaluation

h) Size and Location of Defect

i) Examiner

j) Procedure identification and revision

k) Lighting equipment

Sample of Report please see appendix I.

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POS-PT-01 Rev.01