ASTM F1394-92(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: F1394 − 92 (Reapproved 2012)
Standard Test Method for
Determination of Particle Contribution from Gas Distribution
System Valves
This standard is issued under the fixed designation F1394; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Semiconductor clean rooms are serviced by high-purity gas distribution systems. This test method
presentsaprocedurethatmaybeappliedfortheevaluationofoneormorecomponentsconsideredfor
use in such systems.
1. Scope condensation nucleus particle counter and does not consider
classifying data into various size ranges.
1.1 This test method covers gas distribution system compo-
1.3.1.1 It is questionable whether significant data can be
nents intended for installation into a high-purity gas distribu-
generated from nondynamic components (such as fittings and
tion system.
short lengths of tubing) to compare, with statistical
1.1.1 This test method describes a procedure designed to
significance, to the data generated from the spool piece. For
draw statistically significant comparisons of particulate gen-
this reason, this test method cannot reliably support compari-
eration performance of valves tested under aggressive condi-
sons between these types of components.
tions.
1.3.1.2 If detection or classification of particles, or both, in
1.1.2 This test method is not intended as a methodology for
the size range of laser particle counter (LPC) technology is of
monitoring on-going particle performance once a particular
interest, an LPC can be utilized for testing components. Flow
valve has been tested.
rates,testtimes,samplingapparatus,anddataanalysisoutlined
1.2 Thistestmethodutilizesacondensationnucleuscounter
in this test method do not apply for use with an LPC. Because
(CNC) applied to in-line gas valves typically used in semicon-
ofthesevariations,datafromCNCsarenotcomparabletodata
ductor applications. It applies to automatic and manual valves
from LPCs.
of various types (such as diaphragms or bellows), 6.3 through
1.3.2 This test method specifies flow and mechanical stress
1 1
12.7-mm ( ⁄4 through ⁄2-in.) size. For applications of this test
conditions in excess of those considered typical. These condi-
method to larger valves, see the table in the appendix.
tions should not exceed those recommended by the manufac-
1.2.1 Valves larger than 12.7 mm ( ⁄2 in.) can be tested by
turer. Actual performance under normal operating conditions
this methodology. The test stand must be sized accordingly.
may vary.
Components larger than 12.7 mm ( ⁄2 in.) should be tested
1.3.3 The test method is limited to nitrogen or clean dry air.
while maintaining a Reynolds number of 20000 to 21000.
Performance with other gases may vary.
This is the Reynolds number for 12.7-mm ( ⁄2-in.) components
1.3.4 This test method is intended for use by operators who
tested at a velocity of 30.5 m/s (100 ft/s).
understand the use of the apparatus at a level equivalent to six
months of experience.
1.3 Limitations:
1.3.1 This test method is applicable to total particle count 1.3.5 The appropriate particle counter manufacturer’s oper-
ating and maintenance manuals should be consulted when
greater than the minimum detection limit (MDL) of the
using this test method.
1.4 The values stated in SI units are to be regarded as the
This test method is under the jurisdiction of ASTM Committee F01 on
standard. The inch-pound units given in parentheses are for
Electronics and is the direct responsibility of Subcommittee F01.10 on Contamina-
tion Control.
information only.
Current edition approved July 1, 2012. Published August 2012. Originally
1.5 This standard does not purport to address all of the
approvedin1992.Lastpreviouseditionapprovedin2005asF1394–92(2005).DOI:
10.1520/F1394-92R12. safety concerns, if any, associated with its use. It is the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1394 − 92 (2012)
responsibility of the user of this standard to establish appro- 3.1.12 test flow rate—volumetric flow at test pressure and
priate safety and health practices and determine the applica- temperature.
bility of regulatory limitations prior to use. Specific hazard
3.1.13 test pressure—pressure immediately downstream of
statements are given in Section 6, Hazards.
the test component.
3.1.14 test velocity—the average velocity of the test gas in
2. Referenced Documents
the outlet tube of the test valve (volumetric flow at ambient
2.1 Federal Standard:
pressure and temperature divided by the internal cross-
FED-STD-209D Federal Standard Clean Room and Work
sectional area of the valve outlet). In this test method, the test
Station Requirements, Controlled Environment
velocity is specified to maintain a Reynolds number of 20000
to 21000 (see the table in the appendix).
3. Terminology
3.2 Abbreviations:
3.1 Definitions of Terms Specific to This Standard:
3.2.1 LPC—laser particle counter.
3.1.1 background counts—counts contributed by the test
apparatus (including counter electrical noise) with the spool
4. Significance and Use
piece in place of the test object.
4.1 The purpose of this test method is to define a procedure
3.1.2 condensation nucleus counter (CNC)—light scattering
for testing components intended for installation into a high-
instrument that detects particles in a gaseous stream by
purity gas distribution system. Application of this test method
condensing supersaturated vapor upon the particles.
isexpectedtoyieldcomparabledataamongcomponentstested
for the purposes of qualification for this installation.
3.1.3 control product—sample component that gives
consistent, stabilized counts at or below the expected counts
4.2 Background Testing—This test method uses background
from the test components. The product is run periodically in
testing to ensure that the system is not contributing particles
accordance with the test protocol to ensure that the system is
abovealow,acceptablelevel.Thisensuresthatcountsseenare
not contributing particles significantly different from expected
from the test device, not from a contaminated system. The
levels.
techniques used to obtain background counts do not produce
3.1.3.1 Discussion—The control product may have to be
conditions identical to the conditions existing when a test
changed periodically if its performance degrades with testing.
device is in place. It is recommended that the control products
Between tests, the control product must be bagged in accor-
be run periodically to see that they give consistent results.
dancewiththeoriginalmanufacturer’spackagingandstoredin
These control products should be the lowest particle release
acleanmanner.Thecontrolproductisusedtoallowthesystem
products. They will be additional proof that the system is not
toconsiderthedisruptioncausedbytheactivationofanyvalve
contributing excess particles during the static, dynamic, or
under test, such as significant fluctuations in flow, pressure,
impact portions of the test.
turbulence, and vibration.
4.3 This test method can be used for testing lengths of
3.1.4 dynamic test—test performed to determine particle
tubing. The flow criteria will be identical to that indicated for
contribution as a result of valve actuation.
valves.Atubing test would only include the static background,
3.1.5 impact test—test performed to determine particle con-
the impact background, and the static and impact portions of
tribution as a result of mechanical shock while the component themethod.Adynamicportioncouldbeaddedbyactuatingthe
is in the fully open position.
upstream pneumatic valve (PV1), thus creating a flow surge to
the test length of tubing.
3.1.6 sampling time—the time increment over which counts
are recorded.
5. Apparatus
3.1.7 sample flow rate—the volumetric flow rate drawn by
5.1 Test Gas—Clean, dry nitrogen or air is to be used
thecounterforparticledetection.Thecountermaydrawhigher
(minimum dryness−40°C (−40°F) dew point at 689 kPa gage
flow for other purposes (for example, sheath gas).
pressure (100 psig) and <10 ppm total hydrocarbons).
3.1.8 spool piece—a null component consisting of a straight
5.2 Filters—Electronics grade filters are required to provide
piece of electropolished tubing and appropriate fittings used in
“particle-free” test gas. Each filter must be no more than 10%
place of the test component to establish the baseline.
penetrationinaccordancewithmanufacturer’sspecificationsto
3.1.9 standard conditions—101.3 kPa, 20°C (14.73 psia,
0.02 µm particles and have a pressure drop of less than 6.89
68°F).
kPa at 0.00471 m ⁄s at 689 kPa gage pressure (1 psi at 10
3.1.10 static test—a test performed on an as-received com-
standardft /minat100psiginlet).Thefiltermustbecapableof
ponent in the fully open position. This test establishes particu-
passing less than 70 particles ≥ 0.02 µm/m (2 particles ≥ 0.02
late contribution by the valve to the counting system.
µm/ft ) of test gas under test conditions.
3.1.11 test duration—totaltimerequiredtocompletethetest
5.3 Pressure Regulator—A high-purity electronics grade
procedure.
pressure regulator is required to maintain system test pressure.
5.4 Pressure Gage—A high-purity electronics grade pres-
sure transducer or gage is required to monitor system test
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. pressure.
F1394 − 92 (2012)
5.5 Low-Flow Control Device—A high-purity electronics TFEgasketsisrecommendedinordertominimizetheparticles
grade 0 to 0.00472 m /s flow control device is required for that may be generated by installation of the test piece.
1 3 1
testing 6.3, 9.5, and 12.7-mm ( ⁄4, ⁄8 and ⁄2-in.) components.
5.14 Mechanical Shock Device—A weight dropped on the
5.6 High-Flow Control Device—A high-purity electronics test device is used to provide mechanical shock. Drawing and
grade0to0.0142m flowcontroldeviceisrequiredfortesting component specifications are shown in Section 7.
19, 25.1 and 50.8-mm ( ⁄4, 1 and 2-in.) components.
5.15 Instrumentation—A CNC capable of detecting par-
5.7 Tubing—High-purity electronics grade, electropolished ticles as small as 0.02 µm with counting efficiency of 50%
3 −4 3
12.7-mm ( ⁄2-in.) 316-L tubing is required. Larger diameter (1) withasampleflowrateof0.236×10 m /s,istobeused
tubing is required for testing components larger than 12.7 mm for particle counting. Test durations in this test method have
( ⁄2 in.). been established based on a sampling flow rate of standard
0.0236 L/s.
5.8 Sampler—The sampler is to be constructed according to
the drawing (see Fig. 1) and calculations shown in 8. The
6. Hazards
sampler collects gas from the stream exiting the test device,
6.1 Exhaust from the CNC may contain toxic or flammable
where the sample is near-isokinetic in design.
vapors, or both. Make sure that it is properly vented.
5.9 Upstream Adaptor—The upstream adaptor piece con-
6.2 This test method is to be conducted at a normal indoor
nects 12.7-mm ( ⁄2-in.) tubing to the test device. For 12.7-mm
temperature of between 18°C (64°F) and 26°C (78°F). Envi-
( ⁄2-in.)testdevices,theadaptorisasimpleface-sealconnector.
ronmentaltemperaturewithinthisrangeisnotexpectedtohave
For 6.3-mm ( ⁄4-in.) test devices, the adaptor is a smooth
any measurable effect on particle detection.
1 1
transition between 6.3 and 12.7-mm ( ⁄4 and ⁄2-in.) face-seal
connections. 6.3 Test apparatus shall be enclosed in a Class 100 environ-
ment (in accordance with FED-STD-209D). If a clean hood is
5.10 Downstream Adaptor—The downstream adaptor piece
used, locate the hood within a clean environment. Use proce-
connects 12.7-mm ( ⁄2-in.) tubing of the sampler to the test
dures necessary to maintain Class 100 when handling test
device. For 12.7-mm ( ⁄2-in.) test devices, the adaptor is a
apparatus and test component.
simple face seal connector. For 6.3-mm ( ⁄4-in.) test devices,
the adaptor is a tapered cone between 6.3 and 12.7-mm ( ⁄4 in. 6.4 Take care to protect the test apparatus from excessive
and ⁄2-in.) face-seal connections. vibration. For example, vacuum pumps and compressors shall
be isolated from the system.
5.11 Spool Pieces—Spool pieces shall be the same diameter
as the fittings on the test piece and be 15 cm (6 in.) in length.
7. Sampling
The spool piece is to be installed in the system in place of the
7.1 Theaveragevelocityofgasflowingthroughthesampler
test device while obtaining background counts for the system.
shall approximate the average velocity in the tubing in which
5.12 Fittings—Use face seal connectors or compression
the sampler is inserted. The sample flow rate used to calculate
fittings depending on test component end connections.
the sampler diameter is the total flow drawn by the counter.A
−4 3
5.13 Gaskets—Use tetrafluoroethylene (TFE) or nylon gas- typical CNC counter draws 0.472×10 standard m /s (0.1
3 −4 3
standard ft /min) of which only 0.236×10 standard m /s is
kets for attaching the test device and adapter pieces. New
gaskets should be used for each new connection. The use of used for sampling.
7.2 Gradual expansion to atmospheric pressure is used for
sampling.Avoidcriticalorificeexpansionduetoitscomplexity
and potential maintenance problems.
7.3 Thetipofthesamplingprobeshouldhavea30°taperon
the outside diameter.
7.4 The pick-off point shall be centered within the flow
stream.
7.5 The pick-off point should be approximately 15 diam-
eters of the primary flow tube upstream or downstream of any
connection.
7.6 There is enough volume in the exhaust portion of the
sampler to supply the CNC for 1 min. This volume represents
60 times the volume that will be drawn by the CNC while the
valve is closed during the dynamic testing.
7.7 Nominal sample tube diameters have been calculated
and matrixed in the table in the appendix. In most cases, these
1 3 1
FIG. 1 Sampling Device for Testing ⁄4 , ⁄8, and ⁄2 in. The boldface numbers in parentheses refer to a list of references at the end of
(6.3, 9.5, and 12.7 mm) Valves the text.
F1394 − 92 (2012)
approximate the actual diameters needed for isokinetic
sampling, so that standard tube sizes can be used. Under static
flow conditions the sampler size is within 50% of the size
required to achieve isokinetic sampling. For particles of
interest < 0.5 µm, Hinds and Fissan (2, 3) indicate that any
likely isokinetic sampling biases are insignificant. During
dynamic testing, iso
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