PROCEDURE
FOR
LIQUID PENETRANT TESTING FOR PRESSURE VESSEL, BOILER AND PIPING
(VISIBLE-SOLVENT REMOVABLE TECHNIQUE)
Document No : ExWI-NDT-948 Page : 1 of 10 Revise No : 01 Issue Date: January 06, 2020
Prepared By Reviewed By Approved By
Signature
Name Mr. Sorrawut Sarncharoen Mr. Wichan Chunta Mr. Wichan Chunta
Position NDT Level III NDT Level III NDT Level III
Sign Date January 06, 2020 January 06, 2020 January 06, 2020
Assigned to client Copy No. Total Page
10
Correction History
01 January 06, 2020 Revised to ASME 2019 Edition
00 March 06, 2017 First Issue
Revise No. Revise Date Description

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
Doc. No.: ExWI-NDT-948
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Revise No.: 01
Issue Date: January 06, 2020
TABLE OF CONTENTS
1.0 SCOPE 3
2.0 PERSONNEL 3
3.0 REFERENCE 3
4.0 CONSUMABLE MATERIAL 3
5.0 PROCEDURE 4
6.0 INTERPRETATION 5
7.0 EVALUATION 5
8.0 PROCEDURE QUALIFICATION 5
9.0 ACCEPTANCE CRITERIA 6
10.0 REPAIRS 6
11.0 RE-TESTING OF REPAIR AREAS 7
12.0 POST CLEANING 7
13.0 REPORT 7
14.0 SAFETY 7
ATTACHMENT NO. I : Liquid Penetrant Testing Report 8
ATTACHMENT NO. II : Acceptance Criteria 10

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
Doc. No.: ExWI-NDT-948
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Revise No.: 01
Issue Date: January 06, 2020
1.0 SCOPE
1.1 This liquid penetrant testing method as paragraph 1.3 shall be used for detecting
discontinuities, which are open to the surface of nonporous metal and other material .
The material shape(s) and size(s) to be examined refer to construction drawing.
1.2 This procedure is certified to meet the requirements of A rticle 6 of the ASME Section
V Code.
1.3 Testing method used in this procedure are Visible, solvent-removable penetration
testing method.
2.0 PERSONNEL
2.1 Personnel performing this testing shall be qualified in accordance with Qualitech
Written Practice, which is in accordance with the guidelines of the SNT-TC-1A or
equivalent.
2.2 Personal certified to at least a Level II, who meet the requirements of applicable
code, shall perform, evaluate and report the testing.
3.0 REFERENCE
3.1 ASNT Recommended Practice No. SNT-TC-1A, 2016 Edition.
3.2 ASME Section V, Article 6 “Nondestructive Examination, Liquid Penetrant Examination”
2019 Edition.
3.3 ASME SECTION VIII Div.1“Rule for Construction of Pressure Vessels” 2019 Edition.
3.4 Client’s Project Specification
4.0 CONSUMABLE MATERIALS
4.1 Typical penetrant materials to be used with this procedure are : (Do not intermix PT types).
Item Manufacture Trade Name Penetrant Developer Cleaner/Remover
1 Sherwin Incorporated DUBL-CHEK DP-40 D-100 DR-60
2 MR-Chemie GmbH Marker MR 311R MR 70 MR 85
4.2 All liquid penetrant materials used on nickel base alloys, austenitic or duplex
stainless steels and titanium shall be obtain a certification which include the
penetrant manufacturers’ batch numbers and test results obtained in ac cordance with
Mandatory Appendix II of ASME Section V Article 6.
NOTE All materials, including penetrants, solvents or cleaning agents, developers, etc .,
shall be analyzed individually for residual total sulfur, chlorine and fluorine content
in accordance with Section V, Appendix II, II-640. For nickel base alloys, the
residual total sulfur content shall not exceed 0.1 percent by weight (II-641). For
austenitic stainless steels or duplex stainless steel and titanium, the total halogens
content shall not exceed 0.1 percent by weight (II-642). Cleaning solvents and
agents purchased with known chemical composition do not require analysis .

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
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Revise No.: 01
Issue Date: January 06, 2020
4.3 Light meter
Light meter shall be calibrated at least once a year or whenever a meter shall have
been repaired. If meters have not been in use for one year or more, calibration shall
be done before being used.
5.0 PROCEDURE
5.1 Prepare, clean and dry the surface to be examined an d all adjacent areas within 25
mm).
5.1.1 Remove surface materials such as dirt, rust, scale, weld flu x, spatter, paint,
grease, oily films, water, or other matter that could obstruct the entrance of
the penetrant into a discontinuity. As-welded, as-rolled, or as-forged
condition are generally satisfactory, but surface prepara tion by grinding or
brushing shall be necessary where surface irregularities could interfere with
the final testing results.
5.1.2 When brushing austenitic or nickel base alloys, stainless wire brush shall be
used.
5.2 Wet surfaces shall be dried 1 minutes as minimum before examined by normal
evaporation to ensure that no trace of cleaning agent remains on the surface .
5.3 The temperature of the surface to be examined, the penetrant, the remover and the
developer shall be between 10°C to 50° C throughout the testing. Local heating or
cooling is permitted provided temperatures remain in the range of 10°C to 50°C
5.4 Apply penetrant by brushing or spraying. The penetration time shall be as a minimum
10 minutes and maximum 15 minutes for weld discontinuities and manufacturing
process discontinuities.
5.5 After the penetration time has elapsed, any penetrant remaining on the surface shall
be removed, take care to minimize removal of penetra nt from discontinuities.
5.5.1 Solvent-removable penetrant: Excess solvent-removable penetrant shall be
removed by wiping with clean material or cloth, repeating the operation until
most traces of penetrant has been removed. The remaining traces shall be
removed by lightly wiping the surface with cloth moistened with solvent. To
minimized removal of penetrant discontinuities, care shall be taken to avoid
the use of excess solvent. Flushing the surface with solvent, following the
application of the penetrant and prior to developing, is prohibited.
5.6 Surface shall be dry after excess penetrant removal.
5.6.1 For solvent-removable penetrant, normal evaporation, wiping, or forced air
shall dry the surface. The maximum time is 5 minutes before applying
developer.
5.7 The developer shall be applied as soon as possible after penetrant removal .
Insufficient coating thickness may not draw the penetrant out of discontinuities;
conversely, excessive coating thickness may mask indications. The maximum time is
5 minutes.
5.8 Prior to applying suspension type wet developer to the surface, the developer shall
be thoroughly agitated to ensure adequate dispersion of suspended particles.
Nonaqueous developer shall be applied only to a dry surface. It shall be applied by
spraying. Drying shall be by normal evaporation.
5.9 Developing time for final interpretation begins immediately after the ap plication of a
dry developer or as soon as a wet developer coating is dry.

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
Doc. No.: ExWI-NDT-948
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Issue Date: January 06, 2020
6.0 INTERPRETATION
6.1 Final Interpretation shall be made within 10 to 30 min after the requirements of 5.9
are satisfied. If bleed-out does not alter the testing results, longer periods are
permitted. If the surface to be examined is large enough to preclude complete testing
within the prescribed or established time, the testing shall be performed in
increments
6.2 Characterizing Indication(s). The types of discontinuities are difficult to evaluate if
the penetrant diffuses excessively into the developer. If this condition occurs, close
observation of the formation of indication(s) during application o f the developer may
assist in characterizing and application of the developer may assist in c haracterizing
and determining the extent of the indication(s).
6.3 Color Contrast Penetrants. With a color contrast penetrant, the developer forms a
reasonably uniform white coating. Surface discontinuities are indicated by 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.
Illumination (natural or supplemental white light) of the examination surface is
required for the evaluation of indications. The minimum light intensity shall be 100 fc
(1,076 lx). The light intensity, natural or supplemental white light source, shall be
measured with a white light meter prior to the evaluation of indications or a verified
light source shall be used. Verification of light sources is required to be
demonstrated only one time, documented, and m aintained on file.
7.0 EVALUATION
7.1 All indications shall be evaluated in terms of the acceptance standards as specified
in clause 9.0.
7.2 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.
7.3 Broad areas of fluorescence or pigmentation which could mask indications of
discontinuities are unacceptable, and such areas shall be cleaned and reexamined.
8.0 PROCEDURE QUALIFICATION
A change of a requirement in Table T-621.1 identified as an essential variable shall
require requalification of the written procedure by demonstration. A change of a
requirement identified as a nonessential variable does not require requalification of the
written procedure. All changes of essential or nonessential variables from those specified
within the written procedure shall require revision of, or an addendum to, the written
procedure.

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
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Issue Date: January 06, 2020
Minimum and maximum times shall be limited on various steps listed in Table T-621.3
below.
9.0 ACCEPTANCE CRITERIA
The acceptance criteria shall be as per ASME Section VIII Div.1 (Attachment No.II)
10.0 REPAIRS
10.1 When an imperfection is repaired by chipping or grinding and subsequent repair by
welding is not required, the excavated area shall be blended into the surrounding
surface so as to avoid sharp notches, crevices or corners.
10.2 When an imperfection is to be repaired by welding after the imperfection is thought to
have been removed and prior to making weld repairs, the area shall be examined by
the applicable steps in para. 5.0 to ensure it has been removed or reduced to an
acceptably sized imperfection.

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
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Issue Date: January 06, 2020
11.0 RE-TESTING OF REPAIR AREAS
Repaired areas shall be re-examined by the liquid penetrant testing
12.0 POST CLEANING
After testing, surface shall be cleaned to remove penetrant and developer by solvent or
clean rags.
13.0 REPORT
12.1 Nonrejectable Indications. Nonrejectable Indications shall be recorded as specified
by the construction code.
12.2 Rejectable Indications. Rejectable Indications shall be recorded. The following
data, as a minimum, shall record in the report as shown in Attachment I of this
procedure.
(a) The type of Indications (linear or rounded)
(b) Location and extension (length or diameter or aligned)
14.0 SAFETY
All necessary precautions shall be taken to ensure that all personnel comply with safe
working practice in Qualitech General Safety Manual (SHE-01). Special care shall be
addressed to the used chemical when the dangers of chemical hazards are to be
considered. The proper mask shall be used during applying penetrant materials.

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
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ATTACHMENT NO. I: LIQUID PENETRANT TESTING REPORT

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
Doc. No.: ExWI-NDT-948
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Revise No.: 01
Issue Date: January 06, 2020

L IQ U ID P E NE TR A N T TE S T ING FO R P RE S S URE V E S S E L , B O IL E R
A ND P IP ING ( V IS IB L E - S O L V E N T RE MO V A B L E TE CHN IQ UE )
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ATTACHMENT NO. II : ACCEPTANCE CRITERIA
ASME SECTION VIII Div.1, 2019 Edition