WINGS CORPORATION Doc. No. : WD14-001E Japanwingshome.co.jp/introduction/section4_e.pdfAPPENDIX 7 of ASME Sec.VIII, Div.1, PRESSURE VESSELS ・EXAMINATION OF STEEL CASTINGS ・Safety

The copyright is in Takashi Yagisawa

Translation Start Date: August 8th, 2018

http://wingshome.co.jp/introduction_e.html

WINGS CORPORATION

Japan

Doc. No. : WD14-001E

Sheet 44 of 70

Rev. No. : E0

Title: Introduction of the inspection and testing for the

industrial valves

4. NON-DESSTRUCTIVE INSPECTION (NDI)

Nondestructive testing is more frequently applied to valve parts than destructive inspections.

The main types applied to valve parts are Radiography Examination (RT), Liquid Penetrant Examination

(PT), Magnetic Particle Examination (MT), Ultra Sonic Examination (UT) and etc..

Strain measurement (stress analysis / SM) and leakage test (LT) are also included in the non-destructive

inspection.

In addition, because non-destructive inspection is an important examination affecting quality, the

qualifications of persons engaged in work and the certification system are in the direction of international

unification.

Tests and their judgment are required by qualified personnel.

Several standards stipulate the applicable classification of nondestructive inspection for valves and the like

as follows. (Reference example)

Applicable Standard Classification

Type

Sampling Method Criteria RT

MT

or

PT

UT

ASME B16.34-2004

The American Society

of Mechanical

Engineers,.

Valves-Flanged,

Threaded, and Welding

・Body/Bonnet/Cover

Including the weld portion.

・Applied to the SPECIAL

CLASS

○ ○ ○

１００％

RT(鋳鋼材)；

MANDATORY APPENDIX I

RT/PT/MT(Welding

Portion)；

ASME Sec.VIII, Div.1.

（Safety Factor 1.0）

UT(Forgings)；

MANDATORY APPENDIX

IV

MT(Castings & Forged

Materials)

MANDATORY APPENDIX

II

PT(Castings and Forged

Materials)

MANDATORY APPENDIX

III





WINGS CORPORATION

Japan


Sheet 45 of 70

Rev. No. : E0


industrial valves

Applicable Standard Classification

Type

Sampling Method Criteria RT

MT

or

PT

UT

MANDATORY

APPENDIX 7 of

ASME Sec.VIII, Div.1,

PRESSURE VESSELS

・ EXAMINATION OF

STEEL CASTINGS

・Safety Factor: 1.0

○ ○ ×

In the case of a newly

designed mold and casting

method, a total of five tests

are carried out up to the first

five.

After that, 1 piece is

sampled every 5 pieces.

RT;

Defined for each defect

category as per ASTM

E446/E186/E28/E280.

MT;

Define for each defect

category as per TYPE.ASTM

E125.

PT;

Specification of defect size by

wall thickness.

BS 5998-1983

Quality levels for steel

valve castings,

British Standards

Institute


Castings and Forged

Materials

・Examination areas as per

the Quality Level

○ ○ ×

According to the purchase

specifications.

RT;



E446/E186/E28/E280.

MT;

Linear indication is not

permitted.

Other defects are not exceed

ASTM E125-1965/Type 1,

Degree 2.

PT;

As per MT.

MSS SP-53-1999

Magnetic Particle

Examination Method,

Manufactures

Standardization

Society of the Valve

and Fittings Industry,

Inc.


Castings and Forged

Materials

× ○

MT ×


specifications.

Specification of defect size by

wall thickness.

MSS SP-54-1999

Radiographic

Examination Method,

Manufactures

Standardization

Society of the Valve

and Fittings Industry,

Inc


Castings and Forged

Materials

○ × ×


specifications.



E446/E186/E28/E280.

For reference:

Definition of the sampling method is "New design mold and casting method".

These extraction methods can only be entrusted to the manufacturer's record.





WINGS CORPORATION

Japan


Sheet 46 of 70

Rev. No. : E0


industrial valves

· Comparison of RT criteria for cast steel materials

For ASTM E446 (Wall Thickness up to 50mm):

Imperfection Category

Applicable Standards

B16.34 APPENDIX 7

BS 5998*-1

MSS SP-54 QL-III QL-I&II

Gas A2 A2 A3 A2 A2

Sand B3 B3 B3 B2 B3

Shrink, Type 1 CA2 CA3 CA4 CA3 CA2

Shrink, Type 2 CB3 CB3 CB4 CA3 CB3

Shrink, Type 3 CC3 CC3 CC4 CC2 CC3

Shrink, Type 4 CD3 CD3 CD4 CD2 CD3

Hot tears and cracks None None None None

Insert (Chills, Chaplets) None None None None

Remarks) * - 1 BW Ends are all Level - 2, however, Hot tears, cracks and Insert are rejected.

For ASTM E186 (Wall Thickness from 50mm to 114mm)

Inperfection Category


B16.34 APPENDIX 7

BS 5998*-1

MSS SP-54 QL-III QL-

I&II

Gas A3 A2 A3 A2 A3

Sand B3 B2 B3 B2 B3


Shrink, Type 2 CB3 CB2 CB4 CB3 CB3





For ASTM E280 (Wall Thickness from 114mm to 305mm)

Imperfection Category


B16.34 APPENDIX 7

BS 5998*-1

MSS SP-54 QL-III QL-I&II

Gas A3 A2 A3 A2 A3

Sand B3 B2 B3 B2 B3


Shrink, Type 2 CB3 CB2 CB4 CB3 CB3









WINGS CORPORATION

Japan


Sheet 47 of 70

Rev. No. : E0


industrial valves

4.1 Radiographic Examination

This test irradiates the valve main body with radiation, and it can recognize the state of the defect etc from

the change of the intensity of the transmitted radiation.

X-rays, γ (Ir 192 or Co 60) rays or neutron rays are used as a radiation source.

(1) Typical casting sections showing required radiographic examination as per ASME B16.34.

The above figure is an excerpt from B 16.34.

For details, refer to applicable standards.

For reference:

In MSS SP-54-1999 and BS 5998-1983, "critical areas" are defined as follows and abstractly expressing the

shooting location.

(a) casting solidification;

(b) stress concentration;

(c) ability to contain pressure.





WINGS CORPORATION

Japan


Sheet 48 of 70

Rev. No. : E0


industrial valves

APPENDIX 7 (EXAMINATION OF STEEL CASTINGS) of ASME Sec. VIII, Div. 1 explains "critical

sections" as follows.

“For static castings, the sections where imperfections are usually encountered are abrupt changes in section

and at the junctions of risers, gates, or feeders to the casting. For centrifugal castings, critical sections shall

be interpreted to be any abrupt changes of section, the circumference for a distance of at least 3 in. from each

end, and one additional circumferential band at least 3 in. wide and including the area of the most severe

indication detected by other examination method.

Since APPENDIX 7 is applied to a pressure vessel made of cast steel with a casting factor of 100%, it is not

necessarily applied to valves, but for initial casting, there are Riser, Gate and Feeder, RT may be carried out

to the cutting part. Application of Centrifugal Castings to valves is limited.

The above picture is a picture of shot blast after Mold-Out. Attached to BODY are risers, gates, and feeders.

If there is any incompatibility with the casting design, defects may appear in the vicinity of these (risers, gates, and feeders). In the product clean up these parts.

If these cut points are not included in the shooting range, add these points and verify the casting design.





WINGS CORPORATION

Japan


Sheet 49 of 70

Rev. No. : E0


industrial valves

The above is a picture actually taken of the Riser part. Defect appears in the part surrounded by red line.

If defects are detected as described above, improvement of the casting method will be carried out.





WINGS CORPORATION

Japan


Sheet 50 of 70

Rev. No. : E0


industrial valves

The figure is excerpted from ASTM E 1030 (Radiographic Examination

of Metallic Castings). This is a sample of "Shooting Sketches" showing the position of

the source and film. Purchasers are encouraged to

present the standard "shooting sketches" on the shooting position.

The black part of the figure shows that it is difficult to make a judgment with film after shooting.

It is also necessary to explain to the purchase that there is a part other than judgment applicable like the

neck part of the flange. It is recommended to clarify by describing it in "Shooting Sketches"

mentioned above.





WINGS CORPORATION

Japan


Sheet 51 of 70

Rev. No. : E0


industrial valves

(2) Radiography Procedure

Standards Tytle

MANDATORY APPENDIX I (ASME B16.34)

RADIOGRAPHY EXAMINATION: PROCEDURE AND ACCEPTANCE STANDARDS

ASTM E94 Radiographic Examination

Article 2 (ASME Sec. V)

Radiographic Examination

Note)

In addition to the above, ISO, BS, EN, DIN, etc. are available but will be omitted.

For details of the test method, we recommend that you refer to the above standards or consult with qualified

personnel.

Please note that the values specified in the applicable standards and the order specifications may differ for

the following items. (Cost impact may occur.)

-Identified minimum wire diameter or hole diameter of "Image Quality Indicator / IQI"

-Photographic density of the test part (Photographic Density)

(3) Determination method

The judgment of ASTM E446 / E186 / E280 is classified based on the standard photograph.

Regarding welds, it is judged by defect size or any.





WINGS CORPORATION

Japan


Sheet 52 of 70

Rev. No. : E0


industrial valves

(4) Examination Records

After the test, to record the necessary matters of the following items, and the recording and the test portion

should be kept to allow verification.

a) Name of the examiner

b) Material or product name

c) Date of shooting

d) Transparent photograph identification symbol

e) Material

f) Nominal thickness

g) Transmittance thickness

h) Radiation penetration test equipment

i) Source dimension

j) Used tube voltage or gamma ray source

k) Tube current or Becquerel value used

l) Exposure time

m) Film system used

n) intensifying screen

o) Transmission meter

p) distance between source and film

q) Minimum identification wire diameter or hole diameter of photometer, photographic density range

r) Location of test section and other necessary items

s) Examiner's certification and signature

The test material, symbols can be checked against the results document is not must not appear by stamping

or the like.

In addition, the identification symbol must be displayed on the film so that the certificate can be checked

against the film.

Normally, "Shooting Sketches" is stated in the certificate so that the position of the film can be identified.

Since the observation of the film requires skill, it is recommended that observation and qualified personnel.

Particularly in the case of a cast steel material, there is a difference from the determination of weld defects,

which requires caution.





WINGS CORPORATION

Japan


Sheet 53 of 70

Rev. No. : E0


industrial valves

Reference photo for RT judgment (ASTM E446 / Steel Castings Up to 2in. in Tickness):

Gas Porosity Level A3 Sand Inclusion Level B3

Shrinkage Level CA3 Shrinkage Level CB3

Shrinkage Level CC3 Shrinkage Level CD3

* Please note that the above reference pictures differ in size from the original.

The following URL is helpful for photos of welded parts.

http://www.ndt-

ed.org/EducationResources/CommunityCollege/Radiography/TechCalibrations/RadiographInterp.htm


http://www.ndt-ed.org/EducationResources/CommunityCollege/Radiography/TechCalibrations/RadiographInterp.htm

http://www.ndt-ed.org/EducationResources/CommunityCollege/Radiography/TechCalibrations/RadiographInterp.htm




WINGS CORPORATION

Japan


Sheet 54 of 70

Rev. No. : E0


industrial valves

**Special Topics**

(1) Scope

In order to verify the quality level of the cast steel product, it is desirable to evaluate comprehensively from

these results by carrying out various tests, for example, material inspection, nondestructive inspection,

pressure inspection and the like.

Particularly, the method of defect detection by RT is one effective means.

However, it is economically extremely difficult to apply it to all valves.

In order to carry out RT, the importance of the valve, sampling method, shooting location, shooting method

/ criteria are decided and agreement with the customer is required.

In addition, valves that pass RT are sometimes leaked due to pressure test (leakage from the partition walls).

This information should be an outline of general matters on how to think about cast steel quality when RT is

implemented.

(2) Casting Defects and RT level

When pressure inspection is performed by a valve maker, the main types of casting defects that cause leakage

from the body are shrinkage, cracks, gas holes, etc.

(The features of these defects and the problems of the casting method and the improvement method will be

described later)

About the casting defects which cause the leakage of the valve are included in the valve material, the

investigation results of the cast steel flange type gate valve (CLASS 150 to 900) for the eight Japanese casting

manufacturers were obtained from the Japan Valve Industry Association "Cast steel Quality level survey

report on internal soundness by radiation permeation test of valve material ".

(Authors are also participating in the survey.)

The outline of the survey results is shown below.

1) Percentage of Level 3 or more at RT judgment by Valve Size (Level 2 or lower is taken as acceptance

standard for JPI-7S-39 in Japan):

· 2 "to 4" 30%

· 6 "to 12" 44%

· 14 "or more 46%





WINGS CORPORATION

Japan


Sheet 55 of 70

Rev. No. : E0


industrial valves

2) Percentage of the location where Level 1 to Level 3 occurred:

· Line side flange neck part 28%

· Bonnet side flange neck part 18%

· Valve seat periphery 54%

3) Percentage of the type of defect that caused Level 1 to Level 3:

· Gas Porosity 19%

· Sand Inclusion 26%

· Shrinkage 55%

From these results, it is shown that the probability that a defect (shrinkage cavity) exceeding Level 2 is

generated in the periphery of the valve seat is high for the cast steel product not performing the RT.

However, it seems that the ratio leading to serious complaints due to leakage from the body due to casting

defects is small.

This is considered to be appropriate as confirming the quality of the cast steel against the leakage by the

pressure test performed by the valve manufacturer.

However, it does not guarantee the casting quality (RT critrion) of a product not carrying out RT.

For valves used for critical piping, 100% RT is recommended.

The current RT judgment is the result of planar observation of the defect, and it is difficult to judge whether

the internal defect penetrates the partition wall.

Therefore, the pressure test is an important factor.

In the future, RT criteria will also require the fracture mechanics consideration.





WINGS CORPORATION

Japan


Sheet 56 of 70

Rev. No. : E0


industrial valves

4.2 Magnetic Particle Examination

It is a test method to detect defects by magnetizing a ferromagnetic material such as a steel material and

utilizing adhesion of magnetic powder by the magnetic pole generated in the defect part.

In brief explanation of the principle, when magnetizing a magnetic material, the magnetic flux protrudes to

the defect portion opened on the surface as shown in the following figure, the magnetic powder concentrates

on that portion, it becomes many times the size of the open defect, It is a mechanism to increase the

probability of discovering.

It can only be detected if the defect is open on the surface or if there is a large defect near the surface.

Depending on the method of magnetizing, the following types are often applied to valves in many cases.

PRODS YORK DIRECT MAGNETAIZATION

Note) Linear defects are best detected perpendicular to the direction of the magnetic flux. Since it depends

on the magnetization method, perform the same place in two orthogonal directions.

(The above figure was taken from the homepage of "NDT Resource Center" Iowa State University.)

(1) Examination Areas

All exterior and all accessible interior surfaces of body, bonnet, and cover.

(2) Major Procedures

Magnetic particle examination procedure for castings shall be in accordance with ASTM E 709, Standard

Recommended Practice for Magnetic Particle Examination.

For forgings, plates, and bars, the examination procedures shall be in accordance with ASTMA275, Magnetic

Particle Examination of Steel Forgings.

Major Standards Title

MANDATORY APPENDIX II

(ASME B16.34)

MAGNETIC PARTICLE EXAMINATION: PROCEDURE

AND ACCEPTANCE STANDARDS

ASTM E709 Magnetic Particle Examination

For Reference:

In particular, when flaw detection of the casting surface of the cast steel material is carried out, rust must be

removed sufficiently and the surface should be made as smooth as possible to prevent pseudo defects from

appearing.





WINGS CORPORATION

Japan


Sheet 57 of 70

Rev. No. : E0


industrial valves

As a test method, wet fluorescent magnetic powder flaw detection is recommended.

To carry out fluorescent flaw detection, bring the test material into the dark room and observe it with black

light.

The following photograph is an example in which a linear defect emerges due to black light although it is

extreme. Recently, considering the environment, we should consider the treatment method of the test material

after the test.

(3) Acceptance Criterion

ASME Sec.VIII, APPENDIX 7 and BS 5998 judge grades compared to standard photographs of ASTM E125.

Note:

Before conducting the flaw detection test, paste the

Indicator shown in the figure on the test material and

confirm whether the test conditions are appropriate.





WINGS CORPORATION

Japan


Sheet 58 of 70

Rev. No. : E0


industrial valves


After conducting the test, necessary items out of the following items shall be recorded, so that records can be

collated with the test material.

a) Item name, size, material, heat treatment state and surface condition

b) Test equipment

c) Magnetic powder pattern

d) Dispersion medium of magnetic powder, eg wet method, water ·? g / l

e) Classification of test methods, eg continuous method, residual method, fluorescent magnetic powder, dry

/ wet method, direct current, alternating current and others.

f) magnetization current area, energization time

g) Magnetization method

h) Standard specimen

i) Test result.

j) Test technician, date of examination, examination place, test site





WINGS CORPORATION

Japan


Sheet 59 of 70

Rev. No. : E0


industrial valves

4.3 Liquid Penetrant Examination

A test method of observing flaws as an indication pattern of an enlarged image after infiltrating penetrant

into a flaw opening on the surface of the specimen.

The major test methods are dye penetrant test and fluorescent penetrant test.

Penetrant Removing Developing

(1) Examination Areas

All exterior and all accessible interior surfaces of body, bonnet, and cover.

(2) Major Procedures

Major Standards Tytle

MANDATORY APPENDIX III (ASME B16.34)

LIQUID PENETRANT EXAMINATION: PROCEDURE AND ACCEPTANCE STANDARDS

ASTM E165 Liquid Penetrant Examination

Note: Particularly when flaw detection is performed on the surface of a cast steel material, it is necessary to

make the surface as smooth as possible to prevent false defects from appearing.

As a test method, wet fluorescent penetrant inspection is recommended.

To carry out fluorescent flaw detection, bring the test material into the darkroom and observe it using black

light. Recently, considering the environment, we should consider the treatment method of the penetrant after

the test.

(3) Acceptance Criterion

ASME Sec.VIII, APPENDIX 7 and BS 5998 judge grades compared to standard photographs of ASTM E125.


After conducting the test, necessary items out of the following items shall be recorded, so that records can be

collated with the test material.

a) Item name, size, material, heat treatment state and surface condition

b) Test equipment

c) Instruction pattern

d) Classification of test methods

e) Infiltration time, development time, temperature of the test site

f) Test result

g) Test technician, exam date, test location, test site





WINGS CORPORATION

Japan


Sheet 60 of 70

Rev. No. : E0


industrial valves

4.4 Strain Measurement

The strain measurement test is a test to investigate the stress distribution state of the specimen and the strength

of the stress, and is a test conducted by examining the extent of deformation by applying load to the specimen.

Therefore, strain measurement test is also called stress measurement test, electrical resistance strain gauge

method, magnetostriction method, etc. are used.

In Japan, strain tests may be required for valves to which the High Pressure Gas Safety Act is applied.

(1) Examination Point

There is no clear provision in the place (Body or Bonnet / Cover) where it is presumed that the most stress

occurs at the time of pressurization.

For example:





WINGS CORPORATION

Japan


Sheet 61 of 70

Rev. No. : E0


industrial valves

(2) Test Procedure

Three-wire self-temperature compensated three-axis

rosette gauge as shown in the photograph (type

selected for each material) is affixed, the valve is

pressurized to design pressure or withstand pressure in

several stages, and at each pressure stage (pressurizing

/ depressurizing) Measure the strain value and

calculate the maximum principal stress by the

following method.

Note) The longitudinal modulus of elasticity (Young's modulus) used for the above calculation is the value

described in the Specified Equipment Inspection Regulation or ASME.

Where;

σ1:Maximum principal stress, E: Longitudinal elastic modulus, υ:Poisson's ratio

τmax: Maximum shear stress, γ: Maximum shear strain, Θ: Maximum principal strain direction.

(3) Criteria for judgment

It must be less than allowable stress at design temperature.





WINGS CORPORATION

Japan


Sheet 62 of 70

Rev. No. : E0


industrial valves

4.5 Leak Testing

In order to check the airtightness and watertightness of the valve, the test to detect the presence of leaks,

leakage points or leakage amount is called a leakage test.

Leaked parts include a method of directly observing a leakage point by visual inspection and a method of

inserting a gas such as helium or ammonia into a valve and electrically or chemically detecting these trace

leaks or detecting a leak of the liquid staining agent Method, or presence or absence of foaming of the soap

solution applied to the test section, and the like.

In HANDBOOK issued by ASNT (American Society for Nondestructive Testing), Leak Testing is classified

as follows.





WINGS CORPORATION

Japan


Sheet 63 of 70

Rev. No. : E0


industrial valves

In recent years, overseas regulations concerning suppression of atmospheric emissions of volatile organic

compounds (VOC), such as EPA (Environmental Protection Act) Method 21, 96/61 / EC (EU directive:

concerning integrated pollution prevention and control), TA-Luft / VDI 2440 (Technische Anleitung

Reinhaltung der Luft / Requirements of the guide line) etc., specifications for regulating the leakage from the

valve packing and Gasket part and specifications by the puchaser are increasing.

There are an increasing number of valve makers who are certified by these standards.

Other standards include ASME Sec.V, ARTICLE 10 (LEAK TESTING), BS EN 1779 (Leak Testing) and the

like.





WINGS CORPORATION

Japan


Sheet 64 of 70

Rev. No. : E0


industrial valves

As a leak test on valves, ISO 15848-1 (Industrial valves-Measurement, test and qualification procedure for

fugitive emissions, Part 1: Classification system and qualification procedure for type of valves), Iiso 15848-

2 (Part 2: Production acceptance test) The test method and the judgment standard are stipulated.

The main points of ISO 15848-1 will be explained next.

1) Test pressure: Follow applicable standards or order specifications (eg SHELL-GSI, MESC SPE 77 / 300-

2007 to be mentioned later).

2) Test temperature: Select a temperature range close to the specification from -196 ° C, -46 ° C, room

temperature, 200 ° C, 400 ° C.

3) Operation frequency:

on-off valves → 500 times × 2 thermal cycles (excluding room temperature) +1000 times × 1 thermal

cycle +

1000 times × 1 thermal cycle

control valves → 20,000 times × 2 thermal cycles (excluding room temperature) + 40,000 times × 1

thermal cycle +

40,000 times × 1 thermal cycle

4) Test place and judgment criteria:

Body seals (Gasket part) → 50 ppmv or less

Stem seals (Packing section) → Class A ≤ 10 - 6 mg s - 1. m - 1 (bellow seal or quarter turn valves)

Class B ≤ 10 - 4 mg · s - 1 m - 1 (PTFE Packing or elastomeric seals)

Class C ≦ 10-2 mg.s - 1.m - 1 (flexible graphite packings)

(The amount of leakage is multiplied by the circumference m of Stem.)

5) Test method and test fluid

- Vacuum method (helium only) This is equivalent to Example 1 of the JIS vacuum container method.

(Class A only accepts this Vacuum method.)

-Flushing method (helium or methane) It corresponds to Example 2 or 3 of the JIS vacuum container method

mentioned above.

-Sniffing method (helium or methane) Equivalent to the JIS suction method mentioned above

Caution!

· We recommend Helium Gas for the test fluid. When carrying out with Methane, please ensure sufficient

safety of the equipment and test environment.





WINGS CORPORATION

Japan


Sheet 65 of 70

Rev. No. : E0


industrial valves

<Topics-1>

About units expressing the amount of leakage:

The conversion from "ppm or mg" to "atm.cm 3 or international unit Pa.m 3" is shown below with reference

to helium gas as a reference example.

From ISO 15848-1, Annex A / A.1.7,

Lm = Lv × ρ Formura-1

where Lm: mg / s, Lv: atm.cm 3 / s, ρ: mg / cm 3.

To convert using the above formula, perform under the following conditions;

“In case of the suction amount of the helium detector's sniffer method be Lv = 0.5 to 1.0 atm.cm 3 / s (in the

case of Shimadzu Seisakusho Model MSE-2000)”

Weight (g) of helium 1 ppm, 20 ° C., 1 cm 3 is calculated from p * v = (w / M) * R * T,

w = (M * p * v) / (R * T)

Molecular weight M of He: 4.0026

p: 1 atm

v: 0.001 litter

R: 0.08205447 liter.atm.deg - 1. mol - 1

T: (20 ° C.) 293.16 K

∴ w = 1.665 × 10 -4 (g) = 0.1665 mg / cm 3 (eg, the density of He at 0 ° C. is 0.1785 mg / cm 3)

The Density of He at 1 ° C. at 20 ° C. is 0.1665 × 10^ -6 mg / cm 3,

Therefore, at 1 ppm, 0.5 atm · cm 3 / s, from equation 1,

Lm = 0.5 × 0.1665 × 10 ^- 6 = 0.08325 × 10 ^- 6 (mg / s) = 0.500246 × 10^ - 6 (atm.cm 3 / s) = 0.0506874

× 10 ^- 6 (Pa.m 3 / s)

50 ppm, helium at 20 ° C. has a leakage of about 2.5 × 10^ -6 to 5.1 × 10^ -6 (Pa.m 3 / s).

Note: A helium detector whose measurement can not be measured in ppm requires the above conversion

when the amount of leakage is ppm, but if the amount of suction by the sniffer can not be measured, the

specified value of the amount of leakage will not be accurate.





WINGS CORPORATION

Japan


Sheet 66 of 70

Rev. No. : E0


industrial valves

Conversion from mg / s to atm.cm 3 / s:

From pv = nRT, determine the volume of 1 mg helium at 20 ° C.

p: 1 atm

n = w / M = 0.001 / 4.0026 = 2.498 × 10^-4 mol

R: 82.05447 atm.cm3.deg^-1.mol^-1

T: 293.16 K (20 ° C)

∴v = 2.498 × 10^ -4 × 82.05447 × 293.16 = 6.00896 atm.cm 3

1mg / s = 6.00896 atm.cm3 / s

(In the case of 0 ° C, 1 mg / s = 5.5990 atm · cm 3 / s will be obtained.)

Also,

1 atm.cm3 / s = 0.101325 Pa.m3 / s

Note: The above conversion method from ppm to Leakage Rate is a reference example, and we recommend

that you contact the manufacturer of each helium detector for accurate values.





WINGS CORPORATION

Japan


Sheet 67 of 70

Rev. No. : E0


industrial valves

<Topics-2>

On the main difference between "MESC SPE 77 / 300-2007: PROCEDURE AND TECHNICAL

SPECIFICATION FOR TYPE ACCEPTANCE TESTING (TAT) OF INDUSTRIAL VALVES, APPENDIX

E FUGITIVE EMISSION PROTOTYPE TESTING" and "ISO 15848-1";

1) Leakage amount: Class A (HS) is distinguished from the symbol for class A ≦ 10^ - 6 mg.s ^- 1 m^ - 1,

and values are ≤ 10^ - 5 mg · s ̂ - 1 m ̂ - 1 , But it is applied regardless of Packing / Gasket and Valve structure.

I think that it is extremely difficult value. Furthermore, it must satisfy even during operation.

2) The number of operations is as low as 200 on on off valves and as low as 20,000 on control valves.

3) Class A (HS) also accepts the Sniffing method, but the actual influence of the background is large when

actually testing, it is difficult to measure accurate leakage amount.

It is relatively stable when measuring the leakage amount through the hole in Gland. Since leakage around the entire circumference is

measured in one place, the amount of leakage is larger than the prescribed method.

It becomes unstable when directly measuring the leakage amount of Gland Packing part. According to Shell's provision, we must measure the

whole circumference and add up the peaks. However, do not count up to three times the background.

The photograph is a photograph when the helium leak

test was actually carried out by the French authorized testing institute CETIM. It is a reference example in which Bonnet Yoke

(Gland Packing department) was enclosed in a chamber and carried out by the vacuum container method like this.

Although this method can measure accurate leakage amount, we think that it is difficult depending on low

temperature test, high temperature test, valve shape.

Sniffer Probe

Sniffer Probe





WINGS CORPORATION

Japan


Sheet 68 of 70

Rev. No. : E0


industrial valves

The picture shows an example showing FE TEST of gasket part. It is sealed with aluminum tape to the BODY - BONNET JOINT part, drilled in the GASKET JOINT

space part, tapped off, and it shows a state extended with a stainless steel pipe. In such a state, helium leak can be measured directly at low temperature and high temperature, but we recommend applying it to PROTOTYPE TEST.

Generally, it becomes a method to insert a sniff probe into a hole in aluminum tape. In the low temperature test, valves are lifted once from the cold bath, but with large valves it is dangerous,

so it would be better for customers to approve such a method beforehand. Line flanges can be carried out in the same way.

In case of FE TEST of the gasket part, there is a

method of calculating the leakage amount by the

volume of the gasket space part.

This method is called the Accumulation method.

Please refer to the example below.

When measuring the amount of leakage in the

gasket part by this method, please approve the

customer including calculation method.

The leak detector must be calibrated with a

helium concentration (ppm or %).

A possible raise of helium concentration in a known volume with a atmospheric pressure, during a test

duration, will be a value for a leak rate.

Aluminum tape

Tapping Joint

Extended Pipe

Sniffer Probe





WINGS CORPORATION

Japan


Sheet 69 of 70

Rev. No. : E0


industrial valves

A possibility is to calibrate the leak detector with the helium concentration in the atmosphere

(5 ppm).

The best way for the machine reading is to calibrate the leak detector with a test gas with a known helium

concentration, for example fresh air.

5 ppm helium concentration = 5E-6 on the leak detector.

In this case each ppm helium raise corresponds with a raise of 1E-6 on the leak detector.

The volume of the hood has to be known: determined or calculated.

Leak rate calculation

During the calibration, the sensitivity will be determined.

S=∆cHe / (RK2 – RK1)

where S = sensitivity (ppm/ scale division)

∆cHe = 5 ppm (when air is used)

RK2 = reading on leak detector air (5 ppm helium)

RK1 = reading on leak detector Background (0 ppm helium), If Negligible small, value is “0”.

∆cHe = S · (R2 - R1)

∆cHe = helium concentration raise (ppm)

S = sensitivity (ppm/ scale division)

R2 = reading second test

R1 = reading first test

When a leakage is observed, a leak rate can be calculated:

ql=(∆cHe · Patm · V hood) / ( ∆t · CTG)

where ql= leak rate (mbar·l·s-1)

∆cHe = helium concentration raise (ppm)

Patm = Pressure atmosphere (≈ 1000 mbar)

Vhood = Volume hood (liters)

∆t = duration (seconds)

CTG = Concentration Test Gas

(Quoted from the text of DCI company in the Netherlands.)

This method divides the change in the leakage amount by the elapsed time and multiplies the volume.

It is often done with Helium Concentration 100% = 1, usually at 1 atm / 1013 mbar / 0.1013 x 106 Pa.





WINGS CORPORATION

Japan


Sheet 70 of 70

Rev. No. : E0


industrial valves

<Topics-3>

API 622, Type Testing of Process Valve Packing for Fugitive Emission, but we have made the following

equipment and set tests for Packing.

Main point:

1) Test fluid: Methane Gas

2) Test temperature: room temperature to 260 ° C

3) Test pressure: 0 to 4.237 MPa

4) Operation frequency: 1,500 times 3 thermal cycles

5) Leakage amount: No allowable leakage amount is specified. However, when exceeding 500 ppmv, packing

is re-tightened.

· Other reference:

Guideline VDI 2440 (Association of German Engineers) refers to average gas-like emissions for differing

gasket systems but these are not upper limits as follows;

(Above table from www.valve-world.net.)


Documents

WINGS CORPORATION Doc. No. : WD14-001E Japanwingshome.co.jp/introduction/section4_e.pdfAPPENDIX 7 of ASME Sec.VIII, Div.1, PRESSURE VESSELS ・EXAMINATION OF STEEL CASTINGS ・Safety