PTT Exploration and Production Public Company Limited
PTTEP Engineering General Specification
(Production Asset and Operation Support Group)
Standard
Radiographic Examination Specification
Document No: 10012-STD-6-INT-003-R00
September 2017
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Revision History
Rev
R00
Description of Revision
New Document
Date
10-Oct-17
September 2017, R00
History
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
TABLE OF CONTENTS
1.0
INTRODUCTION...................................................................................................... 1
2.0
PURPOSE ............................................................................................................... 1
3.0
SCOPE .................................................................................................................... 1
4.0
RESPONSIBLE ACTION PARTIES ......................................................................... 2
5.0
DEFINITIONS .......................................................................................................... 4
5.1
5.2
5.3
Language .................................................................................................................................. 4
Terminology .............................................................................................................................. 4
Common Acronyms .................................................................................................................. 4
6.0
REFERENCES......................................................................................................... 5
6.1
6.2
PTTEP Internal References ...................................................................................................... 5
External references ................................................................................................................... 5
7.0
REQUIREMENT....................................................................................................... 6
7.1
7.2
7.3
7.4
Written Procedure ..................................................................................................................... 6
Equipment ................................................................................................................................. 6
Execution .................................................................................................................................. 6
Safety ........................................................................................................................................ 7
8.0
INTERPRETATION .................................................................................................. 8
8.1
8.2
Evaluation ................................................................................................................................. 8
Acceptance Criteria .................................................................................................................10
9.0
DOCUMENTATION ............................................................................................... 11
9.1
9.2
Recording of Indications .........................................................................................................11
Reporting .................................................................................................................................12
10.0
APPENDICES ........................................................................................................ 14
Appendix 1.
Appendix 2.
Technique ....................................................................................................................14
Various Radiographic Technique .............................................................................32
September 2017, R00
TOC
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
1.0
10012-STD-6-INT-003-R00
INTRODUCTION
This Standard (STD) details the Radiographic Testing (RT) which is a nondestructive test
method based on the principle of preferential radiation transmission, or absorption. Areas of
reduced thickness or lower density transmit more, and therefore absorb less, radiation. The
radiation which passes through a test object will form a contrasting image on a film receiving
the radiation. This method is used to inspect materials for hidden flaws by using the ability of
short wavelength electromagnetic radiation to penetrate various materials. Either a high
energy X-ray machine or a gamma radiation source (Ir-192, Co-60 or in rare cases Cs-137)
can be used as a source of photons. There are other methods (e.g. neutron radiography) but
this specification details the general principles for industrial X- and gamma radiography for
flaw detection purposes using film techniques. It is only applicable to metallic products and
materials.
2.0
PURPOSE
The purpose of this document is to provide details of methodology for performing of
implementation of "Radiographic Test" to detect the imperfection that open to surface of
nonporous materials and welds (both metallic and non – metallic). All NDE personnel must
perform his/her work by strictly complying with the detail in this document. This document has
been written for the performing of Radiographic Test for platform structure, pipeline, process
piping, facility equipment and etc.
3.0
SCOPE
This document has been written to be the procedure to perform RT in role of Maintenance and
Inspection for in-services upstream processing facilities. Radiographic Test is the NDE
method which is selected to verify the integrity of equipment by detection of surface and
subsurface discontinuities in all common engineering materials. A further advantage is that the
developed film serves as an excellent permanent record of the test if the film is stored properly
away from excessive heat and light. The disadvantage of radiographic testing is that it may not
detect those flaws which are considered to be more critical (e.g., planner cracks and
incomplete fusion) unless the radiation source is preferentially oriented with respect to the flaw
direction. Further, certain test object configurations (e.g., branch or fillet welds) can make both
the performance of the testing and interpretation of results more difficult. However,
experienced test personnel can obtain radiographs of these more difficult geometries and
interpret them with a high degree of accuracy.
The limitation of this test method is the need for access to both sides of the test object (one
side for the source and the opposite for the film).
September 2017, R00
Page 1 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
4.0
10012-STD-6-INT-003-R00
RESPONSIBLE ACTION PARTIES
4.1 CUSTODIAN

Keep this document updated as necessary and address regulatory changes and
policy improvements.

Ensure that effectiveness and efficiency of the procedures are assessed and audited
on an annual basis, at minimum.

Review and/or update this document when necessary, 3 years maximum interval.

Provide technical recommendations and/or justifications in case of any deviations from
the requirements of this document.
4.2 INSPECTION SUPERVISOR

Control work quality by complying with approved written procedure.

Review NDE report

Perform his/her work in scope of TA1 at worksite.
4.3 TECHNICAL AUTHORITY 1 (TA1)

Management of the standards and mandatory practices pertaining to his/her expertise
under the scope of Maintenance and Inspection.

Provision of technical advice to the ASSET Managers and Corporate functions under
the scope of Maintenance and Inspection.

Performing and/or Reviewing Risk Assessments that are performed under the scope of
Maintenance and Inspection.

Providing advice on proposed changes or deviations of practices under the scope of
Maintenance and Inspection.

Assessment and appointment of lower levels of TA under the scope of Maintenance
and Inspection.

Ensure provision of practices and knowledge share across ASSETs and Projects
under the scope of Maintenance and Inspection.
4.4 TECHNICAL AUTHORITY 2 (TA2)

Provision of technical advice to the ASSET Managers and Corporate functions.

Performing and/or Reviewing Risk Assessments that are performed.

Providing advice on proposed changes or deviations.

To arbitrate technical disputes between TA1s and ASSET Manager.
September 2017, R00
Page 2 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00

Assessment and appointment of TA1.

To act TA1 in case TA1 is not identified.

To provide support and mentoring of TA1's.

Maintain Standards and mandatory practices pertaining to their expertise.

Ensure the best practices and knowledge sharing across ASSETs and Projects.

To be a member of the audit team to assure ASSET and Project compliance with
Company Standards.

To perform verification activities for the Safety Critical Elements.

Responsible for ensuring that Corporate-Level Codes, Standards and Recommended
Practices are in place, approved, up-to-date and maintained.

To act as ASSET/Project level (TA1) for an individual ASSET where and
ASSET/Project level (TA1) is not justified, not available or where there is currently no
individual suitable to fulfil the TA1 position within that asset.
4.5 NDE PERSONNEL

All NDE personnel who perform his/her work for NDE shall be qualified by complying
with minimum requirement of COMPANY standard (document no. 10008-STD-6-INT001-R00), ASNT Recommended Practice SNT-TC-1A and/or approved equivalent by
the applicable code.

The examination shall be performed by NDE personnel qualified to at least level II.
However, NDE level I shall be qualified to assist NDE Level II in performing specific
calibrations, specific tests and specific evaluations and record test results following
specific written instructions provided under the direct supervision from NDE level II.

All NDE personnel of CONTRACTOR who are provided to perform his/her work is
required to show their resume and qualification certificates in advance to the TA1 and
TA2 prior to mobilization.

All NDE personnel of CONTRACTOR who are provided to perform his/her work must
be approved before testing. His/her competency shall be reviewed and approved by
demonstration competency under witness by TA1 and TA2 prior to mobilization.

It is the objective of all NDE personnel to detect and report all significant flaws in
accordance with the relevant codes and specifications.

All NDE personnel shall perform his/her NDE work in accordance with approved
written procedure.
September 2017, R00
Page 3 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
5.0
10012-STD-6-INT-003-R00
DEFINITIONS
A number of different terms are commonly used to describe the work stages, processes, and
approvals which take place during the early stages of a development. This can often be a
source of confusion so the following section is intended to show the PTTEP preferred
terminology as used in this document.
5.1
LANGUAGE
In this document, the words should and shall have the following meanings:
May
Indicates a possible course of action
Must
Indicates a mandatory and regulatory course of action.
Shall
Indicates a mandatory course of action.
Should
Indicates a preferred or logical course of action.
5.2
TERMINOLOGY
Terminology
Description
Approval
The authorization in writing given by the COMPANY to the Contractor to proceed
the work without releasing in any way the Contractor from any of his obligations to
conform with the technical specifications, requisitions, etc. The words “Approve”,
“Approved” and “Approval” shall be construed accordingly
Company
PTT Exploration and Production Public Company Limited and affiliates.
5.3
COMMON ACRONYMS
Set out below in alphabetical order are common acronyms as found within this document:
NDE
Nondestructive Examination
RT
Radiographic Testing
September 2017, R00
Page 4 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
6.0
REFERENCES
6.1
PTTEP INTERNAL REFERENCES
10012-STD-6-INT-003-R00
Internal documents applicable to this document are indicated in the table below.
Document Number
10008-STD-6-INT-001-R00
6.2
Document Title
Inspection and Testing Requirements
EXTERNAL REFERENCES
Codes, standards and regional legislation applicable to this document are indicated in the
table below.
Document Number
Document Title
AWS D1.1
Structural Welding Code
ASME B 31.3
Process Piping
ASME B31.4
Pipeline Transportation Systems for Liquids and Slurries
ASME B31.8
Gas Transmission and Distribution Piping Systems
ASME V
Nondestructive Examination Article 2
ASME VIII div. 1 and 2
Pressure Vessel Design Code
ASTM E 94
Standard Guide for Radiographic Examination
ASTM E 747
Standard Practice for Design, Manufacture and Material Grouping
Classification of Wire Image Quality Indicators (IQI) Used for
Radiology
ASTM E 1025
Standard Practice for Design, Manufacture, and Material
Grouping Classification of Hole-Type Image Quality Indicators
(IQI) Used for Radiology
ASTM E 1255
Standard Practice for Radioscopy
ASTM E 1416
Standard Practice for Radioscopic Examination of Weldments
API 1104
Welding of Pipelines and Related Facilities
API 5L
Specification for Line Pipe
BS EN ISO 11699-1:2011
Non-destructive testing. Industrial radiographic film. Classification
of film systems for industrial radiography
September 2017, R00
Page 5 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
7.0
REQUIREMENT
7.1
WRITTEN PROCEDURE
10012-STD-6-INT-003-R00
Radiographic Test shall be performed in accordance with a written procedure which shall as a
minimum, contain the requirements listed in “ASME section V, Article 2”, ASTM E 94, ASTM E
747 and ASTM E 1025 (with regards to type of construction codes and standards). Change of
the essential variable shall require requalification of the written procedure by demonstration.
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.
The testing shall be done by approved procedure, demonstration under witness by Company.
7.2
EQUIPMENT
Radiographic Test materials are intended to include film, intensifying screens, Image Quality
Indicator (IQI) design, facilities for viewing of radiographs and sources shall be complied with
in ASME section V.
7.3
EXECUTION
The execution of Radiographic Testing is comprised of test arrangement, surface preparation,
identification of radiographs, marking, overlap of films, Image Quality Indicator, technique,
calibration and examination shall be performed by strictly complying with approved written
procedure. The conditions and types of imperfection that this NDE method is able to apply are
shown as below;

All or most standard techniques will detect this imperfection under all or most
conditions;
o
Service-Induced Imperfections: Abrasive Wear (Localized), Corrosion – Pitting
and Erosion
o
Welding Imperfections: Burn Through, Excessive / Inadequate Reinforcement,
Inclusions (Slag / Tungsten), Incomplete Penetration, Misalignment, Porosity, Root
Concavity and Undercut
o
Product Form Imperfections: Cold Shuts (Castings), Inclusions (All Product
Forms) and Porosity (Castings)

One or more standard technique(s) will detect this imperfection under certain
conditions;
o
Service-Induced Imperfections: Corrosion – General / Uniform, Fatigue Cracks,
Hot Cracking and Stress-Corrosion Cracks (Transgranular)
o
Welding Imperfections: Cracks and Incomplete Fusion
September 2017, R00
Page 6 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
o
10012-STD-6-INT-003-R00
Product Form Imperfections: Bursts (Forgings), Cracks (All Product Forms), Hot
Tear (Castings) and Laps (Forgings)
7.4
SAFETY
All testing carried out in accordance with this procedure shall comply with the relevant safety
documents regarding health and safety at work, fire hazards, electrical safety, toxic materials,
safety and working in confined / restrictive compartments. Testing material shall be used in
accordance with the manufacturer’s instructions.
WARNING:
Exposure of any part of the human body to X-rays or gamma-rays can be
highly injurious to health. Wherever X-ray equipment or radioactive sources are in use,
appropriate legal requirements must be applied.
7.4.1

GENERAL PRACTICES
Personnel handling radioactive isotopes and/or X-ray equipment shall be licensed by
the appropriate governmental competent authorities.

Radio isotopes must never be carried on aircraft except in extreme emergency. The
pilot must be made aware of the nature and strength of the cargo.

Radio isotopes must be stored in flame proof shielded containers. The storage area
must be marked with the UN “trefoil” I.D, and access limited to authorised personnel
only.

Relevant lifting certificate for the container such as third party visual inspection
certificate, proof load test certificate and NDT reports are required.

All radiography must be carried out under either a hot or cold work permit (depending
on the technique) and additional complementary work permit. The permit will indicate
(in addition to the normal precautions and etc.) the type and strength of the source
(e.g. Iridium 192, 750 Gbq).

Radiation strength must not exceed 925 Gbq (GigaBecquerels) or 25 Ci (Curie) per
source.

Barrier must be erected around the storage area at the point where the dose rate is
equal to or less than 2.5 µSv/hr (micro Sievert / hour).

Barricades must be erected to a safe distance as calculated by the radiographer using
the strength and purpose of the equipment. The recognised safe distance is regarded
as where the maximum allowable dose rate is 7.5 µSv/hr (micro Sievert / hour).

The barrier should be black and yellow striped tape or flagging with trefoil sign.

Warning signs must be posted, flashing lights are advisable, and an authorised stand
by person in place. A PA announcement should be made before and after the job.
September 2017, R00
Page 7 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00

Film badges must be worn by all operatives.

A radiation survey meter must be positioned.

Dosimeter with valid calibration certificate must be available in event of suspected
contamination.
7.4.2
TRANSPORTATION
The following precautions must be taken:

The source must be in its custom made inner container which is inside a metal locked
box with the UN trefoil symbol clearly visible.

The key for the box will be with the radiographer.

Certification for the source giving type and strength will be carried with the load.

A load recovery package will be attached. This will consist of a secure rope of strength
sufficient for 3 x the load which will be at least 2 times (200%) the maximum depth of
the sea around the jobsite and during transportation. A floating buoy with flashing light
MUST be attached.
8.0
INTERPRETATION
8.1
EVALUATION
Evaluation of Radiographic Testing is comprised of;
8.1.1
QUALITY OF RADIOGRAPHS
All radiographs shall be free from mechanical, chemical, or other blemishes to the extent that
they do not mask and are not confused with the image of any discontinuity in the area of
interest of the object being radiographed. Such blemishes include, but are not limited to:

Fogging;

Processing defects such as streaks, watermarks, or chemical stains;

Scratches, finger marks, crimps, dirtiness, static marks, smudges, or tears;

False indications due to defective screens.
8.1.2
8.1.2.1
RADIOGRAPHIC DENSITY
DENSITY LIMITATIONS
The transmitted film density through the radiographic image of the body of the appropriate hole IQI or
adjacent to the designated wire of a wire IQI and the area of interest shall be 1.8 minimum for single
film viewing for radiographs made with an X-ray source and 2.0 minimum for radiographs made with a
gamma ray source. For composite viewing of multiple film exposures, each film of the composite set
September 2017, R00
Page 8 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
shall have a minimum density of 1.3. The maximum density shall be 4.0 for either single or composite
viewing. A tolerance of 0.05 in density is allowed for variations between densitometer readings.
8.1.2.2

DENSITY VARIATION
General. If the density of the radiograph anywhere through the area of interest varies by more
than minus 15% or plus 30% from the density through the body of the hole IQI or adjacent to
the designated wire of a wire IQI, within the minimum/maximum allowable density ranges
specified in 8.1.2.1, then an additional IQI shall be used for each exceptional area or areas and
the radiograph retaken. When calculating the allowable variation in density, the calculation may
be rounded to the nearest 0.1 within the range specified in 8.1.2.1.

With Shims. When shims are used with hole-type IQIs, the plus 30% density restriction of (a)
above may be exceeded, and the minimum density requirements of 8.1.2.1 do not apply for the
IQI, provided the required IQI sensitivity of 8.1.3.1 is met.
8.1.3
8.1.3.1
IQI SENSITIVITY
REQUIRED SENSITIVITY
Radiography shall be performed with a technique of sufficient sensitivity to display the designated hole
IQI image and the 2T hole, or the essential wire of a wire IQI. The radiographs shall also display the IQI
identifying numbers and letters. If the designated hole IQI image and 2T hole, or essential wire, do not
show on any film in a multiple film technique, but do show in composite film viewing, interpretation shall
be permitted only by composite film viewing.
8.1.3.2
EQUIVALENT HOLE-TYPE SENSITIVITY
A thinner or thicker hole-type IQI than the required IQI may be substituted, provided an equivalent or
better IQI sensitivity, as shown below, is achieved and all other requirements for radiography are met.
Equivalent IQI sensitivity is shown in any row which contains the required IQI and hole. Better IQI
sensitivity is shown in any row which is above the equivalent sensitivity row. If the required IQI and hole
are not represented in the table, the next thinner IQI row may be used to establish equivalent IQI
sensitivity.
Hole-Type
Designation 2T Hole
Designation Equivalent Hole-Type Designations
1T Hole
4T Hole
10
15
5
12
17
7
15
20
10
17
25
12
20
30
15
25
35
17
30
40
20
35
50
25
September 2017, R00
Page 9 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
40
60
30
50
70
35
60
80
40
80
120
60
100
140
70
120
160
80
160
240
120
200
280
140
8.1.4
EXCESSIVE BACKSCATTER
8.1.4.1
BACKSCATTER RADIATION
A lead symbol “B,” with minimum dimensions of 1⁄2 in. (13 mm) in height and 1⁄16 in. (1.5 mm) in
thickness, shall be attached to the back of each film holder during each exposure to determine if
backscatter radiation is exposing the film.
8.1.4.2
EXCESSIVE BACKSCATTER
If a light image of the “B,” as described in 8.1.4.1 appears on a darker background of the radiograph,
protection from backscatter is insufficient and the radiograph shall be considered unacceptable. A dark
image of the “B” on a lighter background is not cause for rejection.
8.1.5
EVALUATION
TA1 and TA2 shall be responsible for the review, interpretation, evaluation, and acceptance of
the completed radiographs to assure compliance with the requirements of approved written
procedure and the referencing Code Section. As an aid to the review and evaluation, the
radiographic technique documentation required by 9.1.3.1 shall be completed prior to the
evaluation. The radiograph review form required by 9.1.3.2 shall be completed during the
evaluation. The radiographic technique details and the radiograph review form documentation
shall accompany the radiographs. Acceptance shall be completed prior to presentation of the
radiographs and accompanying documentation to the Inspector.
8.2
ACCEPTANCE CRITERIA
Acceptance standards are primarily based upon the length, width and size of the actual
indication. Acceptance criteria shall be in accordance with the construction code.
September 2017, R00
Page 10 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
9.0
DOCUMENTATION
9.1
RECORDING OF INDICATIONS
10012-STD-6-INT-003-R00
9.1.1 NONREJECTABLE INDICATIONS
Nonrejectable indications shall be recorded as specified by the referencing Code Section for
Company baseline and further reference.
9.1.2 REJECTABLE INDICATIONS
Rejectable indications shall be recorded. As a minimum, the type of discontinuity, location and
extent (length or diameter or aligned) shall be recorded.
9.1.3 EXAMINATION RECORDS
9.1.3.1
RADIOGRAPHIC TECHNIQUE DOCUMENTATION DETAILS
The following information shall be provided as minimum;

Identification as required for System of Identification.
o
The system shall be used to produce permanent identification on the radiograph
traceable to the contract, component, weld or weld seam, or part numbers, as
appropriate. In addition, the Manufacturer’s symbol or name and the date of the
radiograph shall be plainly and permanently included on the radiograph. This
identification system does not necessarily require that the information appear as
radiographic images. In any case, this information shall not obscure the area of
interest.

The dimensional map (if used) of marker placement.

Number of radiographs (exposures)

X-ray voltage or isotope type used

Source size

Base material type and thickness, weld thickness, weld reinforcement thickness, as applicable

Source-to-object distance

Distance from source side of object to film

Film manufacturer and Manufacturer’s type / designation

Number of film in each film holder/cassette

Single- or double-wall exposure

Single- or double-wall viewing
9.1.3.2
RADIOGRAPH REVIEW FORM
The following information shall be provided as minimum;
September 2017, R00
Page 11 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00

List of each radiograph location

The information required in 9.1.3.1, by inclusion or by reference

Evaluation and disposition of the material(s) or weld(s) examined

Identification (name) of the representative who performed the final acceptance of the
radiographs

9.2
Date of evaluation
REPORTING
For each radiograph, or set of radiographs, a test report shall be made giving information on
the radiographic technique used, and on any other special circumstances which would allow a
better understanding of the results. Details concerning form and contents should be specified
in special application standards or be agreed on by the contracting parties. If inspection is
carried out exclusively to this standard then the test report shall contain at least the following
information:

Name of the testing company

Unique report number

Object

Material

Stage of manufacture

Nominal thickness

Radiographic technique and class

System of marking used

Test arrangement and film position plan, if required

Radiation source, type and size of focal spot and equipment used

Selected film systems, screens and filters

Tube voltage and current or source activity

Time of exposure and source-to-film distance

Type and position of image quality indicator

Reading of I.Q.I and minimum film density

Conformance to this International Standard

Any deviation from agreed standards

Name, certification and signature of the responsible person(s)
September 2017, R00
Page 12 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification

10012-STD-6-INT-003-R00
Date of exposure and report
The test report shall then contain the test results, including a detailed description and location
of the indications (with a sketch where appropriate) and a statement as to whether they meet
the acceptance criteria.
September 2017, R00
Page 13 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
10.0 APPENDICES
Appendix 1.
1)
Technique
Classification of Radiographic Techniques
Radiographic techniques are divided into two classes:

Class A: Basic Techniques.

Class B: Improved Techniques.
Class B technique will be used when Class A may be insufficiently sensitive. Better
techniques, compared with Class B, are possible and may be agreed between the contracting
parties by specification of all appropriate test parameters. The choice of radiographic
technique shall be agreed between the parties concerned.
If, for technical reasons, it is not possible to meet one of the conditions specified for the Class
B, such as the type of radiation source or the source-to-object distance f, it may be agreed
between the parties that the condition selected may be that specified for Class A. The loss of
sensitivity shall be compensated by an increase of minimum density to 3.0 or by using a
higher contrast film system. Because of the better sensitivity compared to Class A, the test
sections may be regarded as examined within Class B.
2)
General
2.1 Test Arrangement
The test arrangement consists of the radiation source, test object and the film or film-screen
combination in cassette and depends on the size and shape of the object and the accessibility
of the area to be tested. Generally, one of the arrangements illustrated in Section 2.1.1 to
Section 2.1.7 should be used. The beam of radiation shall be directed at the middle section
under examination and shall be normal to the surface at that point, except when it is known
that certain flaws are better revealed by a different alignment of the beam. When radiographs
are taken in a direction other than normal to the surface, this shall be indicated in the test
report. Double-wall techniques are acceptable only if single wall techniques are not practical.
September 2017, R00
Page 14 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
September 2017, R00
t
f
1
2
material thickness
t
b
source-to-object distance
f
distance between the film and the surface of the object nearest
the source
film
2
b
radiation source with an effective optical focus size d
1
Arrangement 1: Single-wall penetration – Object with plane walls
KEY
2.1.1
10012-STD-6-INT-003-R00
Page 15 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
2.1.2
10012-STD-6-INT-003-R00
Arrangement 2: Single-wall penetration – Object with curved walls – Source off-
September 2017, R00
t
f
1
2
distance between the film and the surface of the object
nearest the source
b
b
material thickness
t
N.B. This arrangement is preferred to Arrangement 4
source-to-object distance
film
2
f
radiation source with an effective optical focus size d
1
KEY
center on concave side – Film on convex side
Page 16 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
September 2017, R00
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
radiation source with an effective optical focus size d
film
source-to-object distance
material thickness
distance between the film and the surface of the object
nearest the source
2
f
t
b
2
b
t
f
t
2
1
N.B. One advantage of this technique is that the whole circumference
may be radiographed in one exposure. This arrangement is preferred
to Arrangements 2, 4 or 5.
f
b
2.1.3
1
KEY
1
2
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Arrangement 3: Single-wall penetration – Object with curved walls – Source located
centrally
Page 17 of 33
Radiographic Examination Specification
2.1.4
10012-STD-6-INT-003-R00
Arrangement 4: Single-wall penetration – Object with curved walls – Source on
September 2017, R00
t
f
1
2
material thickness
t
b
source-to-object distance
f
distance between the film and the surface of the object nearest
the source
film
2
b
radiation source with an effective optical focus size d
1
KEY
convex side – Film on concave side
Page 18 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
1
2
radiation source with an effective optical focus size d
film
source-to-object distance
material thickness
distance between the film and the surface of the object
nearest the source
Because the source is close to the upper wall, flaws should
not be evaluated in this wall.
1
2
f
t
b
N.B.
2.1.5
f
t
KEY
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Arrangement 5: Double-wall penetration – Single-wall evaluation – Source and film
outside
September 2017, R00
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Page 19 of 33
b
1
2
N.B. Flaws in the upper wall may be evaluated. For some applications
the radiation beam might be used at a different angle (i.e. not
perpendicular to the centre of the film).
distance between the film and the surface of the object
nearest the source
b
source-to-object distance
f
material thickness
film
2
t
radiation source with an effective optical focus size d
1
KEY
b
2.1.6
September 2017, R00
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
f
t
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Arrangement 6: Double-wall penetration – Double-wall evaluation – Source and film
outside
Page 20 of 33
Radiographic Examination Specification
2.1.7
10012-STD-6-INT-003-R00
Arrangement 7: Single-wall penetration – Object with plane or curved walls of
different thicknesses or materials – Two films with the same or
material thickness
distance between the film and the surface of the object
nearest the source
t
b
2
source-to-object distance
film
2
f
radiation source with an effective optical focus size d
1
1
b
KEY
different speeds
t
f
2.2 Surface Preparation
In general, surface preparation is not necessary, but where surface imperfections or coatings
might cause difficulty in detecting defects, the surface shall be ground smooth or the coatings
shall be removed. Unless otherwise specified radiography shall be carried out after the final
stage of manufacture, e.g. after grinding or heat treatment.
September 2017, R00
Page 21 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
2.3 Identification of Radiographs
Symbols shall be affixed to each section of the object being radiographed. The images of
these symbols shall appear in the radiograph outside the region of interest where possible and
shall ensure unequivocal identification of the section.
2.4 Marking
Permanent markings on the object to be examined shall be made in order to locate accurately
the position of each radiograph. Where the nature of the material and / or its service
conditions does not permit permanent marking, the location may be recorded by means of
accurate sketches.
2.5 Overlap of Films
When radiographing an area with two or more separate films, the films shall overlap
sufficiently to ensure that the complete region of interest is radiographed. This shall be verified
by a high-density marker, on the surface of the object which will appear on each image.
2.6 Image Quality Indicator

Standard IQI Design: IQIs shall be either the hole type or the wire type. Hole-type
IQIs shall be manufactured and identified in accordance with the requirements or
alternates allowed in ASTM E 1025. Wire-type IQIs shall be manufactured and
identified in accordance with the requirements or alternates allowed in ASTM E 747,
except that the largest wire number or the identity number may be omitted. ASME
standard IQIs shall consist of detail in ASME V, Article 2. those in ASME V, Table T233.1, for hole type and those in Table ASME V, T-233.2, for wire type.

Alternative IQI Design: IQIs designed and manufactured in accordance with other
national or international standards may be used provided the requirements of either (a)
or (b) below, and the material requirements of ASME V, T-276.1, are met.
(a) Hole Type IQIs. The calculated Equivalent IQI Sensitivity (EPS), per ASTM E
1025, Appendix X1, is equal to or better than the required standard hole type
IQI.
(b) Wire Type IQIs. The alternative wire IQI essential wire diameter is equal to or
less than the required standard IQI essential wire.
3)
Recommended Techniques
3.1 Choice of X-Ray Tube Voltage & Radiation Source
3.1.1
X-Ray Equipment
To maintain good flaw detection sensitivity, the X-ray tube voltage should be as low as
possible. The maximum values of tube voltage versus thickness are given in Figure 1.
September 2017, R00
Page 22 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Figure 1: Maximum X-ray voltage for X-ray devices up to 500 kV as function of
penetrated wall thickness
3.1.2
Other Radiation Sources
The permitted penetrated thickness ranges for gamma ray sources and X-ray equipment
above 1 MeV are given in Table 1.
Table 1:
Penetrated thickness range for gamma ray sources and X-ray equipment with
energy from 1 MeV and above for steel, copper and nickel-base alloys
Radiation source
170
Penetrated thickness, w (mm)
Test Class A
Test Class B
w5
w5
1  w  15
2  w  12
10  w  40
14  w  40
20  w  100
20  w  90
40  w  200
60  w  150
Tm
Yb1)
75
Se2)
192
Ir
60
Co
X-ray equipment with energy
30  w  200
50  w  180
from 1 MeV to 4 MeV
X-ray equipment with energy
50  w
80  w
from 4 MeV to12 MeV
X-ray equipment with energy
80  w
100  w
> 12 MeV
1) For aluminum and titanium the penetrated material thickness is 10mm  w  70mm for
Class A and 25  w  55 for class B
2) For aluminum and titanium the penetrated material thickness is 35mm  w  120mm for
Class A
169
September 2017, R00
Page 23 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
On thin steel specimens, gamma rays from 192Ir and 60Co will not produce radiographs having
as good a defect detection sensitivity as X-rays used with appropriate technique parameters.
However because of the advantages of gamma ray sources in handling and accessibility,
Table 1 gives a range of thicknesses for which each of these gamma ray sources may be
used when the use of X-rays is not practicable.
For certain applications wider wall thickness ranges may be permitted, if sufficient image
quality can be achieved.
In cases where radiographs are produced using gamma rays, the set-up time required to
position the source shall not exceed 10% of the total exposure time.
3.2 Film Systems and Screens
For radiographic examination, film system classes shall be used in accordance with BS EN
ISO 11699-1:2011.
For different radiation sources the minimum film system classes are given in Tables 2 and 3.
When using screens, good contact between film and screen is required. This may be achieved
by using vacuum-packed films or by applying pressure.
For different radiation sources, Tables 2 and 3 show the recommended screen materials and
thicknesses.
Other screen thicknesses maybe used provided it is agreed between the contracting parties
provided the required image quality is achieved.
September 2017, R00
Page 24 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
Table 2:
10012-STD-6-INT-003-R00
Film system classes and metal screens for the radiography of steel, Cu- and
Ni-based alloys
Penetrated
wall
Radiation source
thickness
w (mm)
X-ray potentials
≤ 100 kV
X-ray potentials
> 100 kV to 150 kV
X-ray potentials
> 150 kV to 250 kV
Film system
class1)
Class A Class B
Class A
Class B
None or up to 0.03mm front and back
screens of lead
T3
169Yb
w<5
170Tm
w≥5
T3
X-ray potentials
> 250 kV to 500 kV
TYPE AND THICKNESS OF METAL
SCREEN
w ≤ 50
T2
T2
T2
T3
T3
w > 50
Up to 0.15mm front and back screens of lead
0.02mm to 0.15mm front and back screens of
lead
None or up to 0.03mm front and back
screens of lead
0.02mm to 0.15mm front and back screens of
lead
0.02mm to 0.3mm front and back screens of
lead
0.1mm to 0.3mm front screen of lead2)
0.02mm to 0.3mm back screen of lead
0.1mm to 0.2mm front and back screens of
lead2)
0.02mm to 0.2mm
0.1mm to 0.2mm front
front screen of lead screen of lead2)
0.02mm to 0.2mm back screen of lead
75Se
T3
T2
192Ir
T3
T2
T3
T3
0.25mm to 0.7mm front and back
Screens of steel or copper3)
T3
T2
0.25mm to 0.7mm front and back
screens of steel or copper3)
T2
T2
T2
60Co
X-ray equipment with
energy from 1 MeV to
4 MeV
w ≤ 100
w > 100
w ≤ 100
w > 100
w ≤ 100
X-ray equipment with
energy above 4 MeV
to 12 MeV
100 < w ≤ 300
w > 300
w ≤ 100
X-ray equipment with
energy > 12 MeV
T3
T2
100 < w ≤ 300
w > 300
T3
T3
Up to 1mm front screen of copper, steel or
tantalum4)
Back screen of copper or steel up to 1mm
and
tantalum4) up to 0.5mm
T2
Up to 1mm front screen of tantalum5)
No back screen
T3
Up to 1mm front screen of tantalum5)
Up to 0.5mm back screen of tantalum
1) Better film system classes may also be used
2) Ready packed films with a front screen up to 0.03mm may be used if an additional lead screen of
0.1mm is placed between the object and the film
3) In Class A also 0.5mm to 2mm screens of lead may be used
4) In Class A lead screens 0.5mm to 1mm may be used by agreement between Company and
Contractor
5) Tungsten screens may be used by agreement
September 2017, R00
Page 25 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
Table 3:
10012-STD-6-INT-003-R00
Film system classes and metal screens for aluminum and titanium
Radiation source
Film system class1)
Class A
Class B
X-ray potentials
≤ 150 kV
X-ray potentials
> 150 kV to 250 kV
X-ray potentials
> 250 kV to 500 kV
Type and thickness of intensifying
screen
None or up to 0.03mm front and up to 0.15mm
back screens of lead
0.02mm to 0.15mm front and back screens of
lead
T3
T2
0.1mm to 0.2mm front and back screens of lead
0.02mm to 0.15mm front and back screens of
lead
0.2mm front screens2) and 0.1mm to 0.2mm
back screens of lead
169Yb
75Se
1) Better film system classes may also be used
2) Instead of 0.2mm lead, a 0.1mm screen with an additional filter of 0.1mm may be used
3.3 Alignment of Beam
The beam of radiation shall be directed to the center of the area being inspected and shall be
normal to the object surface at that point, except when it can be demonstrated that certain
inspections are best revealed by a different alignment of the beam. In this case an appropriate
alignment of the beam can be permitted.
3.4 Reduction of Scattered Radiation
Scattered radiation reaching the film is an important cause of reduced image quality,
particularly with X-rays between 150 kV and 400 kV. Scattered radiation can originate from
both inside and outside the specimen. In order to minimize the effect of scattered radiation,
the area of the field of radiation shall be masked, so that the beam is limited to the area of
interest. This is normally done by masking the primary cone of the radiation beam, either with
a physical cone or with a diaphragm on the tube head. The film shall also be shielded from
radiation scattered from other parts of the specimen or from objects behind or beside the
specimen. This can be done by using a back intensifying screen of extra thickness or by using
a sheet of lead behind the film screen combination; this extra sheet may by used inside the
cassette or placed immediately behind the cassette. Depending on the set-up, typical lead
thicknesses are in the range of 1 mm. to 4 mm. If the upper edge of a thick specimen is within
the radiation field, a method of reducing undercutting scatter is generally necessary. The
following diagram shows two typical methods.
September 2017, R00
Page 26 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Film
10012-STD-6-INT-003-R00
Lead sheet
Radiographic Examination Specification
Methods of reducing the effect of scattered radiation
With 192Ir and 60Co radiation sources or in case of edge scatter, a sheet of lead can be used as
a filter of low energy scattered radiation between the object and the cassette. The thickness of
this sheet is 0.5 mm to 2 mm dependent on the penetrated thickness.
With X-rays of 6 MV energy or more used without back intensifying screens, shielding against
scattered radiation is not necessary, unless there is scattering material close behind the film.
In general, with X-rays between 150 kV and 400 kV and with gamma rays, if a beam restrictor
cannot be used, such as when panoramic exposures are being made, the exposures shall be
made in as large a room as possible, so that extraneous scatter is attenuated by distance; the
September 2017, R00
Page 27 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
specimens, whenever possible, shall be well above floor level and the floor near the specimen
shall be covered with lead.
The effect on scattered radiation shall be checked for each arrangement by a lead letter B
(with a height of minimum 10 mm and a thickness of minimum 1.5 mm) placed immediately
behind each cassette.

If the image of this symbol appeared on the radiograph, it shall be rejected.

If the symbol is invisible the radiograph is acceptable and sufficiently protected against
scattered radiation.
3.5 Source-To-Object Distance
The minimum source-to-object distance fmin depends on the source size d and on the objectto-film distance b. The distance f, shall, where practicable, be chosen so that the ratio of this
distance to the source size d, i.e. -f/d, is not below the values given by the following equations:
For Class A:
f
 7. 5  b 2 3
d
(1)
For Class B:
f
 15  b 2 3
d
(2)

If the distance b < 1.2 t the dimension b in equations (1) and (2) and Figure 2 shall be
replaced by the nominal thickness t.

For determination of the source-to-object distance, fmin, the nomogram in Figure 2
may be used.

The nomogram below is based on equations (1) and (2).
In Class A, if planar imperfections have to be detected the minimum distance fmin shall be the
same as for Class B in order to reduce the geometric unsharpness by a factor of 2. In critical
technical applications of crack-sensitive materials more sensitive radiographic techniques than
Class B shall be used. If the radiation source could be placed centrally inside the object to be
radiographed (Arrangement 3) to achieve a more suitable beam direction and to avoid a
double wall technique (Arrangements 5 and 6), this method shall be preferred. The reduction
in minimum source-to-object distance should not be greater than 50%.
September 2017, R00
Page 28 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
Figure 2: Monogram for determination of minimum source-to-object distance fmin in
relation to of object-to-film distance and the source size
3.6 Maximum Area for A Single Exposure
The ratio of the penetrated thickness at the outer edge of an evaluated area of uniform
thickness to that at the center beam shall not be more than 1.1 for Class B and 1.2 for Class
A. The densities resulting from any variation of penetrated thickness should not be lower than
those indicated in Section 3.7 and not higher than those allowed by the available illuminator,
provided suitable masking is possible.
3.7 Density of Radiographs
Exposure conditions should be such that the total density of the radiograph (including base
and fog density) in the inspected area is greater than or equal to that given in Table 4.
September 2017, R00
Page 29 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
Table 4:
10012-STD-6-INT-003-R00
Density of radiographs
Class
Density1)
A
≥ 2.02)
B
≥ 2.32)

A measuring tolerance of ± 0.1 is permitted.

May be reduced by special agreement between the contracting parties to 1.5.

May be reduced by special agreement between the contracting parties to 2.0.
High densities may be used with advantage where the viewing light is sufficiently bright in
accordance with Section 3.9.
In order to avoid unduly high fog densities arising from film ageing, development or
temperature, the fog density shall be checked periodically on a non-exposed sample taken
from the films being used, and handled and processed under the same conditions as the
actual radiograph. The fog density shall not exceed 0.3. Fog density here is defined as the
total density (emulsion and base) of a processed, unexposed film.
When using a multi film technique with interpretation of single films the density of each film
shall be in accordance with Table 4.
If double film viewing is requested the density of one single film shall not be lower than 1.3.
The acceptable geometric unsharpness shall be within the limitations given in the table 5 or
applicable standard.
Table 5:
No
Geometric Unsharpness Limitations
Material Thickness, in (mm)
Ug , Maximum, in. (mm)
1
Under 2 (50)
0.020 (0.51)
2
2 through 3(50-75)
0.030 (0.76)
3
Over 3 through 4 (75-100)
0.040 (1.02)
4
Greater than 4 (100)
0.070 (1.78)
Note: Material thickness is thickness on which the IQI is based.
The acceptable sensitivity for various thickness components and Number of IQI and
placement location of the IQI shall be in accordance with applicable standard or code.
September 2017, R00
Page 30 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
3.8 Processing
Films are processed in accordance with the conditions recommended by the film and chemical
manufacturer to obtain the selected film system class. Particular attention shall be paid to
temperature, developing time and washing time. Residue Thiosulfate on radiographs shall be
checked using Kodak Hypo Test Kit or other equivalent and approved test method. The
amount of thiosulfate ion residue shall be less than 0.05 gm/m2. The radiographs should be
free from imperfections due to processing or other causes which would interfere with
interpretation.
3.9 Film Viewing Condition
The radiographs should be examined in a darkened room (or other equivalent, approved
specification) on a viewing screen with an adjustable luminance (or other equivalent, approved
specification). The viewing screen should be masked from the area of interest.
September 2017, R00
Page 31 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
Appendix 2.
10012-STD-6-INT-003-R00
Various Radiographic Technique
These various radiographic techniques as shown in Appendix 2 shall be performed by
complying with ASME V, Article 2 Mandatory Appendices. List of radiographic technique was
presented as below;

In-Motion Radiography
In-motion radiography is a technique of radiography where the object being
radiographed and/or the source of radiation is in motion during the exposure. In-motion
radiography may be performed on weldments when the following modified provisions
to those in ASME V, Article 2, are satisfied.

Real-Time Radiographic Examination
Real-time radioscopy provides immediate response imaging with the capability to
follow motion of the inspected part. This includes radioscopy where the motion of the
test object must be limited (commonly referred to as near real-time radioscopy). Realtime radioscopy may be performed on materials including castings and weldments
when the modified provisions to ASME V, Article 2, as indicated herein are satisfied.
ASTM E 1255 shall be used in conjunction with this Appendix as indicated by specific
references in appropriate paragraphs. ASTM E 1416 provides additional information
that may be used for radioscopic examination of welds.

Digital Image Acquisition, Display, and Storage for Radiography and Radioscopy
Digital image acquisition, display, and storage can be applied to radiography and
radioscopy. Once the analog image is converted to digital format, the data can be
displayed, processed, quantified, stored, retrieved, and converted back to the original
analog format, for example, film or video presentation. Digital imaging of all
radiographic and radioscopic examination test results shall be performed in
accordance with the modified provisions to ASME V, Article 2, as indicated herein.
September 2017, R00
Page 32 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version
Radiographic Examination Specification
10012-STD-6-INT-003-R00
LAST PAGE – INTENTIONALLY BLANK
September 2017, R00
Page 33 of 33
UNCONTROLLED when printed, visit PTTEP Intranet for latest version