1、Designation: F1057 17Standard Practice forEstimating the Quality of Extruded Poly (Vinyl Chloride)(PVC) Pipe by the Heat Reversion Technique1This standard is issued under the fixed designation F1057; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers a procedure for estimating thequality of extruded poly (vinyl chlor
3、ide) (PVC) plastic pipes byobserving the reaction of pipe specimens after exposure to hotair in the oven at 180 6 5C for 30 min duration.1.2 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to e
4、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevel
5、opment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Significance and Use2.1 This practice is applicable to distinguish between prop-erly and improperly extruded PVC plastic pipe. It can be usedto:2.1.1 Re
6、veal incomplete exsiccation of compound before orduring extrusion (Note 1),2.1.2 Determine the presence of stress in the pipe wallproduced by the extrusion process (Note 2),2.1.3 Determine whether unfused areas are present, and2.1.4 Reveal contamination.NOTE 1Residual moisture in the compound vapori
7、zes at extrusiontemperatures and is normally evacuated as it forms vapor. Pockets ofmoisture trapped in the pipe wall result from incomplete exsiccation of thecompound, and may reduce the physical properties of the pipe.NOTE 2Minor residual stress in the pipe will not impair fieldperformance and han
8、dleability. High-residual stress has no proven effecton performance, but may impair handleability during installation.3. Apparatus3.1 Air Circulating Oven, thermostatically controlled, ca-pable of operating at 180 6 5C (356 6 9F) and capable ofmeeting the recovery requirement of 4.3. Additionally, t
9、heoven must have heat generation (power) capacity such that therecovery achieved while at a constant oven set point. The airtemperature with the oven (that is, the test temperature) is to bemonitored within 3 in. from the outer edge of the testspecimen; make assurances that the temperature does notc
10、ontact the test specimen.NOTE 3The oven should be vented to the outside of the building.NOTE 4Monitoring of the test temperature within the oven mayrequire a secondary temperature monitoring device in addition to thetemperature monitoring device within the oven control system.4. Procedure4.1 Prepare
11、 specimens of pipe 150 mm (6 in.) long or longerwith ends cut square so that they stand perpendicular on endwhen placed in the oven.4.1.1 Cut staves from pipes whose size prevents insertion offull round specimens in the oven. Prepare large-diameter pipestaves so that their lengths parallel to the pi
12、pe axis are 150 mm(6 in.) or longer.4.2 Examine the specimens and note any unusual featuressuch as discoloration, inclusions, or pinholes in the cut edge.4.3 Place the specimens of whole pipe in the preheated ovenso that each specimen stands on end with sufficient separationbetween them so that hot
13、air can flow freely between the pipes.Place specimens of pipe staves on the floor of the preheatedoven so that they rest on their longitudinal edges and so that hotair can flow freely around them. Record the time when the airin the oven directly adjacent to the test specimen recovers to180C (356F).
14、Recovery must occur within 15 min or less.After an additional 30 min of exposure within the testtemperature tolerance of 180 6 5C, remove the specimens,taking care not to alter any heat effects.4.4 Examine the specimens within 3 min after removal fromthe oven, while still hot. With a sharp knife, cu
15、t whole pipespecimens lengthwise at approximately 60 circumferentialintervals, resulting in six pipe staves of approximately equal1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestMethods.Current edi
16、tion approved Feb. 15, 2017. Published April 2017. Originallyapproved in 1987. Last previous edition approved in 2010 as F105710. DOI:10.1520/F1057-17.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
17、 PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organizatio
18、n Technical Barriers to Trade (TBT) Committee.1widths. Cut specimens being tested in the form of staves intothree roughly equal segments. Note the following for thereport:4.4.1 The shape of the pipe ends and the pipe barrel,4.4.2 The condition and appearance of both the inner andouter surfaces of th
19、e material, and4.4.3 The condition and appearance of the cut edges of thematerial.NOTE 5Care should be exercised when removing samples from theoven, as pipe with thinner walls may have degraded during conditioning.5. Interpretation5.1 A suggested interpretation of the results observed isgiven in App
20、endix X1.6. Report6.1 Report the following information, where applicable:6.1.1 Information given by the pipe marking, including thenominal size of pipe, the type of pipe, and the date code;6.1.2 Form in which the pipe was tested;6.1.3 Date of the test and test temperature;6.1.4 Extent and nature of
21、any distortion at the ends or in thebarrel of the specimen;6.1.5 Condition and appearance of the outer surface;6.1.6 Condition and appearance of the inner surface;6.1.7 Appearance of the cut edges, and6.1.8 Any other changes attributable to the test.6.1.9 Evidence of any of the conditions listed in
22、2.1:incomplete exsiccation of compound, stress in the pipe wall,unfused areas, and contamination.7. Precision and Bias7.1 No statement is made about either the precision or biasof Practice F1057 for estimating the quality of PVC pipe, sincethe result merely states whether there is conformance to the
23、criteria for acceptability suggested by the interpretation.8. Keywords8.1 heat reversion; PVC pipeAPPENDIX(Nonmandatory Information)X1. SUGGESTED INTERPRETATION OF RESULTSX1.1 The specimens should be deemed to be satisfactory ifnone of the following effects are reported:X1.1.1 Evidence of the presen
24、ce of stress in the pipe wall,commonly appearing as fish-scaling of any severity (see Fig.X1.1) for an illustration of fish-scaling);X1.1.2 Evidence of the incomplete exsiccation of com-pound before or during extrusion, appearing as wall separation(see Fig. X1.2 and Fig. X1.3 for illustrations of wa
25、ll separa-tion);X1.1.3 Evidence of incomplete exsiccation of compound orcontamination, or both, appearing as blisters on the outer orinner surface (see Fig. X1.4 and Fig. X1.5 for illustrations ofblistering);X1.1.4 Contamination made evident by the test (see Fig.X1.4 for an illustration of contamina
26、tion); andX1.1.5 Evidence of contamination, appearing as wall sepa-ration caused by pockets of granular material composed ofunfused compound or foreign material. (Fig. X1.3 illustratesthe general appearance, except that the voids will be filled witha granular material and may appear at any point in
27、the wall.)F1057 172NOTE 1Severe fish-scaling indicates uneven cooling in the sizing sleeve during extrusion. Resulting wall stresses are released by the heat reversiontest. Note the flared end, another indication of this effect.FIG. X1.1 Severe Fish ScalingF1057 173NOTE 1Severe wall separation revea
28、ls the presence of moisture in the extrudate. This usually indicates plugged or inadequate vacuum control.FIG. X1.2 Severe Wall SeparationF1057 174NOTE 1Less severe wall separation shows the presence of moisture in the extrudate. Poor vacuum control is indicated. Surface blistering may notbe present
29、.FIG. X1.3 Less Severe Wall SeparationF1057 175NOTE 1External blistering is pronounced in this case and shows the presence of moisture in the extrudate. Less severe blistering requires carefulexamination. Dark axial lines below the number tag are signs of contamination by burnt PVC compound picked u
30、p inside the extruder head.FIG. X1.4 External BlisteringF1057 176SUMMARY OF CHANGESCommittee F17 has identified the location of selected changes to this standard since the last issue (F105710)that may impact the use of this standard.(1) Section 6 revised to include reporting of evidence of any ofthe
31、 conditions noted in 2.1 and the test temperature.(2) Clarified the oven as an “Air Circulating Oven,” and addedthe word “circulating”.(3) Added language from 2.1 to figure descriptions in Appen-dix X1.NOTE 1Internal blistering will usually accompany pronounced external blistering and severe wall se
32、paration as an indication of gross vacuum controlproblems.FIG. X1.5 Internal BlisteringF1057 177ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determin
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