1、Designation: F327 08 (Reapproved 2015)Standard Practice forSampling Gas Blow Down Systems and Components forParticulate Contamination by Automatic Particle MonitorMethod1This standard is issued under the fixed designation F327; the number immediately following the designation indicates the year of o
2、riginaladoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes how to connect, prepare, andsample pressu
3、rized gas systems (having up to 19.1-mm (0.75-in.) diameter lines) for particulate contamination by using anautomatic monitor.1.2 The values stated in MKS units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address al
4、l of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For hazardstatements, see Section 5.2. Terminology2.1 Definiti
5、ons:2.1.1 downstream terminal pointthe point in a gas systemfrom which gas is fed into a further system or component,usually the designated “sample port.”2.1.2 filtered gas systema gas system that is equipped withrequired filtration devices to furnish gas that is suitably cleanfor the intended appli
6、cation.2.1.3 purgeto flush a gas supply system or componentwith a regulated flow of gas.2.1.4 sample portthe designated point in a gas system orcomponent from which a representative gas sample may betaken.3. Summary of Practice3.1 The pressurized gas system or component and theapparatus are prepared
7、 in accordance with the requirements ofthe users sample analysis procedure. The sensing unit of theautomatic particle monitor is connected to the designatedsample port which is under purge condition. The systemflow-rate is adjusted to the sample flow rate requirement. Allthe gas passing through the
8、sensing unit is monitored forparticulate contamination until the required sample volume hasbeen analyzed.4. Apparatus4.1 Automatic Monitor, with sensor that sizes and counts allentering fluid in accordance with the users requirements forpressure, flow, temperature, and accuracy.4.2 Filtered Gas Syst
9、emSee Fig. 1.4.3 Stop Watch or Timer, with a + 1, 0-s resolution.4.4 Miscellaneous Fittings, as needed for sampling pointadaption, cleaned and packaged within system contaminationrequirements.4.5 Connecting Lines, cleaned and packaged within systemcontamination requirements.4.6 Flowmeter, calibrated
10、 for the sample port fluid, flow, andtemperature requirements.5. Hazards5.1 Personnel must stand clear of exiting gas.5.2 Ear protection must be used when gas flow approachessonic velocity.5.3 All lines and associated system components must beconnected and operated within the requirements of recogni
11、zedsafety codes.6. Procedure6.1 Establish a minimum continuous purge pressure of 6.89kPa (1 psig) gage or 2.83 dm3/min (0.1 ft3/min), flow from thefiltered gas pressure supply.6.2 Connect one end of a suitable connecting line to thepurge outlet of 6.1, and then connect the other end to the inletof t
12、he component or system to be sampled.NOTE 1If the system to be sampled is already connected to the filteredgas pressure supply, then establish the purge as noted in 6.1.1This practice is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the d
13、irect responsibility ofSubcommittee E21.05 on Contamination.Current edition approved May 1, 2015. Published June 2015. Originallyapproved in 1972. Last previous edition approved in 2008 as F327 08. DOI:10.1520/F0327-08R15.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
14、ocken, PA 19428-2959. United States16.3 Connect a suitable connecting line from the sample portto the inlet of the automatic monitor sensing device. (When nosample port is designated, use the down-stream terminal pointfrom which purge gas is flowing.)6.4 Increase the purge to one of the following:6.
15、4.1 8.49-dm3/min (0.3-ft3/min) flow,6.4.2 34.5-kPa (5-psig) gage pressure, or6.4.3 5 % of system operating pressure when this pressure isless than 34.5-kPa (5-psig) gage.6.5 Surge Pressure Cleaning:6.5.1 Quickly increase the continuous purge pressure for a5-s duration, three times at 1-min intervals
16、 in accordance withone of the following:6.5.1.1 To 689.5-kPa (100-psig) gage pressure,6.5.1.2 To 113.2-dm3/min (4.0-ft3/min) flow,6.5.1.3 70 % of system operating pressure when this oper-ating pressure is below 689.5 kPa (100 psig) gage.6.5.1.4 In accord with a given system operationrequirement, but
17、 not to exceed the rated pressure of the sensingunit.6.5.2 Reduce the purge pressure to the level in 6.4 after eachsurge pressure application of 6.5.1 (that is during 1-mininterval).6.6 Connect a flowmeter to the outlet of the automaticmonitor sensor and adjust the flow versus time to achieve arequi
18、red sample volume within the capability of the sensor.Remove the flowmeter after adjusting the flow.6.7 Set automatic monitor display to zero.6.8 Simultaneously begin automatic particulate counting,sizing and timing of volumetric flow.6.9 Record particulate contamination counts on the monitordisplay
19、 for the required sample volume.6.10 Adjust the continuous purge to the level in 6.4.6.11 Evaluate results and if requirements of contaminationlevels are acceptable, disconnect the monitor and secure thesystem in accordance with the users requirements.6.12 If results are rejected, repeat 6.5 6.12.7.
20、 Precision7.1 Each testing agency has the responsibility of judging theacceptability of its own results. The precision of the results isa function of the procedures (Note 2), facilities utilized, as wellas compliance to the recommended industry state-of-the-artpractices in cleanliness. Reproducible
21、analysis determinationsby different users can be achieved only with identical facilitiesand trained conscientious personnel.NOTE 2Every effort should be made to eliminate outside contamina-tion during operations.ASTM International takes no position respecting the validity of any patent rights assert
22、ed in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by t
23、he responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive
24、 careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Interna
25、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Filtered Gas SystemF327 08 (2015)2
