1、Designation: F3220 17Standard Practice forPrioritizing Sewer Pipe Cleaning Operations by UsingTransmissive Acoustic Inspection1This standard is issued under the fixed designation F3220; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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. Scope1.1 This practice covers procedures for assessing the block-age within gravity-fed sewer pipes using transm
3、issive acousticsfor the purpose of prioritizing sewer pipe cleaning operations.2The assessment is based on an acoustic receiver measuring theacoustic plane wave transmitted through the pipe segmentunder test in order to evaluate the blockage condition of anentire segment and to provide an onsite ass
4、essment of theblockage within the pipe segment. (1, 2, 3, 4, 5)31.2 The scope of this practice covers the use of the trans-missive acoustic inspection as a screening tool. The blockageassessment provided by the acoustic inspection should be usedto identify and prioritize pipe segments requiring furt
5、hermaintenance action such as cleaning or visual inspection, orboth. Thereby, also identifying the pipe segments which aresufficiently clean and do not require additional maintenanceaction.1.3 This standard practice does not address structural issueswith the pipe wall.1.4 The inspection process requ
6、ires access to the manhole(MH) from ground level. It does not require physical access tothe sewer line by either the equipment or the operator.1.5 This standard practice applies to all types of pipematerial.1.6 The inspection process requires access to sewers andoperations along roadways or other lo
7、cations that are safetyhazards. This standard does not describe the hazards likely tobe encountered or the safety procedures that must be carriedout when operating in these hazardous environments.1.7 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses
8、 are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safe
9、ty and health practices and determine the applica-bility of regulatory limitations prior to use.1.9 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International St
10、andards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Terminology2.1 Definitions:2.1.1 authority, nparty responsible for the generation andverification of performance to job specification(s) and contractrequirements.2.1.2 blockage a
11、ssessment, nthe aggregate blockagewithin a pipe segment between two adjacent MHs.2.1.3 closed circuit television (CCTV), na closed circuitpipeline inspection television system including a camera,camera transporter, integrated lighting, central control system,video monitor, and recording device.2.1.4
12、 coordinated universal time (UTC), nis the primaryinternational time standard for regulating clocks and time.2.1.5 geographic information system (GIS), nsystem de-signed to capture, store, manipulate, analyze, manage, andpresent all types of spatial or geographical data.2.1.6 global position system
13、(GPS), nspace-based naviga-tion system that provides location and time information any-where on or near the earth where there is an unobstructed lineof sight to four or more GPS satellites.2.1.7 manhole (MH), nvertical shafts intersecting a sewerthat allows entry to the sewer for cleaning, inspectio
14、n, andmaintenance.2.1.8 pipe segment, nthe section of a sewer line betweentwo adjacent MHs.1This practice is under the jurisdiction of ASTM Committee F36 on Technologyand Underground Utilities and is the direct responsibility of Subcommittee F36.20on Inspection and Renewal of Water and Wastewater In
15、frastructure.Current edition approved April 1, 2017. Published May 2017. DOI: 10.1520/F3220-17.2The transmissive acoustic inspection is covered by Patent US8220484B2.Interested parties are invited to submit information regarding the identification of analternative(s) to this patented item to the AST
16、M International Headquarters. Yourcomments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO
17、 Box C700, West Conshohocken, 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 b
18、y the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.1.9 segments acoustic fingerprint (SAF), nacoustic fea-ture set which characterize a pipe segment. The acousticfeature set is used in classifying the blockage assessment. (2, 6)2.2 Abbreviation:2.2.1 IDidentification3. Sum
19、mary of Practice3.1 Transmissive acoustic inspection operational procedureis based on measuring the signal received from an activeacoustic transmission through a pipe segment. Fig. 1 depictsthe general configuration of a transmissive acoustic inspection.The acoustic transmitter generates sound waves
20、 just below theentrance to the MH which couple into the connecting sewerline segments. The sound wave propagates in the air gap abovethe wastewater flow from the speaker to the receiving micro-phone attached to the acoustic receiver located at the adjacentMH. The acoustic receiver measures the acous
21、tic plane wavefrom the transmitted signal in order to evaluate the blockagecondition of an entire segment and provides an onsite blockageassessment. Both the speaker and the microphone are placedjust within the opening of the MH and should never come incontact with the wastewater flow. The operators
22、 have norequirement for confined space entry.3.2 Transmissive acoustic inspection principle of operationis based on the observation that a pipe segment is a naturalacoustic waveguide. Commonly encountered sanitary sewerdefects, such as roots, grease, pipe sags, and pipe breakagesnaturally absorb or
23、reflect acoustic energy. These defectschange a segments acoustic properties and produce a measur-able impact on the received signal at the microphone, that is,the segments acoustic fingerprint (SAF). Each segment has anindividual SAF representative of its current state. Transmissiveacoustic inspecti
24、on measures and assesses the SAF to deter-mine the Blockage Assessment, that is, an estimate of theaggregate blockage within the pipe segment between theacoustic transmitter and acoustic receiver.4. Significance and Use4.1 Significance:4.1.1 Collection system maintenance requires allocatingcleaning
25、resources to the right place prior to system failure(sanitary sewer overflows, mainline blockages, and buildingbackups). Transmissive acoustic inspection provides a tool toassist in allocating cleaning resources by prioritizing pipesegments based on their blockage assessment and therebyfacilitating
26、efficient cleaning resource allocation.4.1.2 This standard practice provides minimum require-ments and suggested practices regarding the transmissiveacoustic inspection of gravity-fed sewer line blockage assess-ment to meet the needs of maintenance personnel, engineers,contractors, authorities, regu
27、latory agencies, and financinginstitutions.4.2 Limitations and Appropriate Uses:4.2.1 The blockage assessment provided by the transmissiveacoustic inspection may not resolve the type of blockage(s)within the pipe segment nor resolve the location(s) of theblockage(s) within the pipe segment.4.2.2 Due
28、 to the physics associated with transmissive acous-tic inspection, the blockage assessment may be confoundeddue to:(1) Structural designs resulting in poor acoustic coupling,(2) Pipe segments completely filled with water, forexample, full pipe sag or inverted siphon, and(3) Transient conditions with
29、in the pipe, for example,active lateral discharge or temporary flow surcharges.These issues are addressed as part of the performance criteriaspecified in X1.5.4.2.3 Due to physics associated with acoustics and trade-offs in equipment design for conducting transmissive acousticinspection, there are l
30、imitations based on the following pipesegment attributes:(1) Pipe diameter,(2) Pipe segment length,(3) MH depth, and(4) Flow levels.Inspections conducted outside the manufacturers recom-mended ranges for these pipe segment attributes may result inthe transmissive acoustic blockage assessment deviati
31、ng fromthe performance criteria specified in X1.5.4.2.4 Inspections conducted between non-adjacent MHs, forexample, skipping an intermediate MH, may result in thetransmissive acoustic blockage assessment deviating from theperformance criteria specified in X1.5.5. Procedure5.1 If the work is to be co
32、nducted by an outside contractor,apart from the provisions generally included in an inspectionFIG. 1 Transmissive Acoustic Inspection System OperationF3220 172services contract, the transmissive acoustic inspection contractshould define and assign responsibilities for the followingitems:(1) Access t
33、o the site of work is to be provided to the extentthat the authority is legally able to so provide or, if not so able,a written release from responsibility for the performance ofwork at sites where access cannot be made available;(2) MH numbering system for all areas of the project;(3) Location, exp
34、osure, and accessibility of all MH shouldbe provided; and(4) Geographic Information System (GIS) maps should beprovided, when available.5.2 The transmissive acoustic inspection procedure detailedin this practice is based on the transmissive acoustic inspectionequipment meeting the minimum requiremen
35、ts detailed inAppendix X1.5.3 The transmissive acoustic inspection should only beconducted for pipe segments which meet the manufacturersrecommended specifications for: pipe diameter, pipe segmentlength, MH depth, and flow levels.5.4 The transmissive acoustic inspection shall be conductedusing the f
36、ollowing procedure for each pipe segment undertest. The acoustic transmitter and the acoustic receiver shall beplaced on adjacent MHs by their respective field operators. Thetransducers (microphone and speaker) shall be placed withinthe MH, as illustrated in Fig. 1.5.5 The inspection shall follow th
37、e manufacturers recom-mendation for the equipment with the procedure outlined asfollows:5.5.1 Based on the authoritys policy for providing a pipesegments length, the acoustic receiver operator enters thelength of the pipe segment under test. This parameter is used inassessing the blockage assessment
38、. The pipe segments lengthshould be based on the authoritys GIS data, when available,and when deemed to be sufficiently accurate as specified by themanufacturers requirements, for example, pipe segmentslength is entered to within 650 ft.5.5.2 The field operators initiate the automated test. The test
39、shall be started on both the acoustic transmitter and acousticreceiver within the time interval specified by the equipmentmanufacturer.5.6 Following each inspection, the field operator shallrecord the following: acoustic receiver identification (ID),unique blockage assessment ID, upstream MH ID, dow
40、nstreamMH ID, pipe segments location information, blockageassessment, date, and time. The operators recorded dataduplicate and augment the data recorded electronically by thetransmissive acoustic inspection equipment and is used in thedata registration quality control (7.3 and 7.4).5.7 The transmiss
41、ive acoustic inspection equipment opera-tion shall be verified on a daily basis prior to use. Only theverification procedure specified by the equipment manufacturershall be used. The verification results will be electronicallyrecorded by the transmissive acoustic inspection equipment.5.8 On a daily
42、basis, the data recorded electronically by thetransmissive acoustic equipment shall be uploaded for reportgeneration and data registration quality control.6. Report6.1 A report shall be produced as described in 6.2 through6.4. The objective of the report is to provide clear and conciseinformation to
43、 assist in prioritizing cleaning operations on thepipe segments inspected.6.2 Daily Verification ReportA table listing the operationverification results. The table is based on data recordedelectronically by the transmissive acoustic inspection equip-ment. Each table entry will include: the date, the
44、 time, and theresults of the equipment operation verification. If an operationverification fails, then the table entry will indicate the correc-tive measures taken as well as an additional operation verifi-cation entry to show that the corrective measures were suc-cessful.6.3 Summary of Pipe Section
45、s TestedA table of pipesections tested shall be produced that shows the name/numberof the upstream and downstream MHs, the distance betweenMHs as specified by the authoritys GIS data (when available),the distance between MHs as measured by using the inspectionequipment global position system (GPS) l
46、ocation estimates, thepipe length specified by the operator in the field as recorded bythe equipment, the acoustic receiver device ID, measurementtiming verification, the blockage assessment ID, the blockageassessment based on the operator specified pipe length in thefield, and the blockage assessme
47、nt based on the corrected pipelength. In addition, the table shall indicate whether the:(1) Pipe segment location was verified, that is, location wasverified by correlating the field operator recorded informationwith the transmissive acoustic inspection equipment GPSlocation estimates and the author
48、itys GIS data;(2) Pipe segment was tested based on skipping an interme-diate MH due to the intermediate MH not being located or notbeing accessible; and(3) Pipe segment was not tested based on not being able tolocate or access two adjacent MHs.6.4 Field Recorded Electronic DataThe following reportsw
49、ill be provided based on the data recorded by the transmissiveacoustic inspection equipment:6.4.1 A table of the unedited Field Recorded ElectronicData, as illustrated in Fig. 2. The table will include for eachpipe segment evaluated: unique measurement identification,coordinated universal time (UTC), GPS location, operator pipelength setting, blockage assessment, and acoustic receiverstatus. The authority will have access to the unedited FieldRecorded Electronic Data.6.4.2 Graphical representation shall be provided of the dataas illustrated in Fig. 3.6.4.3 W
