1、Designation: C1745/C1745M 11C1745/C1745M 18Standard Test Method forMeasurement of Hydraulic Characteristics of HydrodynamicStormwater Separators and Underground Settling Devices1This standard is issued under the fixed designation C1745/C1745M; the number immediately following the designation indicat
2、es theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method concerns measurement of sele
3、cted hydraulic characteristics of hydrodynamic separators and undergroundsettling devices critical to their function as stormwater treatment devices.1.2 Units tested shall be of a size commonly manufactured, not a scale model.1.3 As each stormwater treatment device is unique in design, so are its hy
4、draulic characteristics (flow versus head and losscoefficients). A sufficient number of accurately measured data points are needed to define properly the hydraulic characteristics ofeach test unit. Therefore, it is imperative that the unit setup and subsequent testing methodologies be well defined a
5、nd executedto ensure accurate flow and elevation data.1.4 This test method addresses gravity flow operation only. It does not address performance of units operating under pressurizedconditions.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The
6、 values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associate
7、d with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationall
8、y recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D3858 Test Metho
9、d for Open-Channel Flow Measurement of Water by Velocity-Area MethodD4409 Test Method for Velocity Measurements of Water in Open Channels with Rotating Element Current MetersD5089 Test Method for Velocity Measurements of Water in Open Channels with Electromagnetic Current MetersD5242 Test Method for
10、 Open-Channel Flow Measurement of Water with Thin-Plate WeirsD5389 Test Method for Open-Channel Flow Measurement by Acoustic Velocity Meter SystemsD5413 Test Methods for Measurement of Water Levels in Open-Water BodiesD5640 Guide for Selection of Weirs and Flumes for Open-Channel Flow Measurement of
11、 Water2.2 ASME Standard:3MFC-3M Measurement of Fluid Flow in Pipes Using Orifice, Nozzle, and Venturi3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 inlet (or outlet) rounding, nradius of fillet at inside pipe junction with separator structure.1 This test method is under the j
12、urisdiction of ASTM Committee C27 on Precast Concrete Products and is the direct responsibility of Subcommittee C27.70 on PrecastConcrete Products for Stormwater Management.Current edition approved Sept. 15, 2011May 1, 2018. Published October 2011May 2018. Originally approved in 2011. Last previous
13、edition approved in 2011 asC1745/C1745M - 11. DOI: 10.1520/C1745_C1745M-11. 10.1520/C1745_C1745M-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Doc
14、ument Summary page on the ASTM website.3 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an
15、 indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to
16、 be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 This test method describes procedures and equipment required to measure the hydraulic characteristics of hydrodynamicsep
17、arators and underground settling devices used for treating stormwater runoff.4.2 Other standards that may be useful to reference include: Test Methods D3858, D4409, D5089, D5242, D5389, D5413,Guide D5640, and ASME MFC-3M (see Section 2).5. Significance and Use5.1 Each device has unique flow patterns
18、 and turbulence characteristics. In addition, each device exhibits a wide range ofefficiencies as discharge, particle size, particle density, and flow viscosity (that is, water temperature) change.The testing procedurein Section 7 will help develop the parameters necessary to input into a function t
19、hat describes the performance of a device undera wide range of application conditions.6. Apparatus6.1 The test unit shall be set up to reflect actual field installation parameters to the greatest degree possible. Influent and effluentpipes shall have a Mannings roughness coefficient not greater than
20、 0.013 and shall be the minimum diameter recommended bythe device manufacturer. Pipe type, diameter, slope (2 to 3 %), orientation, and inlet/outlet roundings shall be recorded and reportedfor each test. The influent pipe shall be a minimum of ten pipe diameters in length, or 6 m 20 ft whichever is
21、less, to ensure auniform approach flow to the test unit, and an effluent pipe of length equivalent to three pipe diameters with a free-fall conditionat its downstream end.6.2 All components of the experimental setup shall be inspected immediately before any testing to confirm that no damage orobstru
22、ction is present and that there are no sediments or other deleterious materials therein. No leakage Leakage in system pipingor from the unit during the test is allowable during the test.as long as the leakage rate is less than 0.1 % of the measured flow rate.7. Test Parameters and Methodologies7.1 T
23、hree major parameters shall be measured and recorded for use in establishing a units hydraulic characteristics: flow, waterelevations, and water temperature.7.1.1 Water ElevationPressure heads or water elevations shall be recorded for each condition tested to determine the headelevations. The locati
24、ons of elevation measurements shall be fixed for all flow conditions. Elevation measurements shall berecorded in the influent and effluent pipes at locations 260.1 pipe diameters upstream and downstream of the unit usingpiezometer taps in the pipe inverts. Internal measurements shall be recorded at
25、a location that allows determination of bypass flow.Measurements are to be recorded using a data acquisition (DA) system and differential pressure (DP) cell or point-gage systemadjusted to a known reference. Manual measurements using an engineers ruler are acceptable for estimated elevations and sha
26、llbe recorded as such.NOTE 1When supercritical flow occurs in the outlet pipe, the energy head at the outlet may appear to exceed the energy head at the inlet leading toerroneous determination of a loss coefficient. Under this condition, the critical depth at the outlet shall be determined and used
27、for calculation of the unitloss coefficient.7.1.2 Flow MeasurementThe accuracy of the flow measurement shall be within 62 %65 % for controlled laboratory testing.The acceptable coefficient of variation of measurements is 0.03. The methodology for flow measurement includes the gravimetricmethod and o
28、pen-channel and closed-conduit (full-pipe) flow meters. Suitable methods include, but are not restricted to, velocityarea sensors, appropriate weirs and flumes, and pressure drop measurement methods using orifices, nozzles, or venturi tubes.7.1.3 TemperatureTests shall be run at a water temperature
29、of 18 to 20C 64 to 68F (see water temperatures not to exceed26.7C 80F. Note 2). At a minimum, water temperatures in the sump of the test unit shall be recorded three times, at thebeginning, the middle, and the end of each test. The average temperature shall be used in data reduction and reporting.NO
30、TE 2Tests may be run outside of specified temperature range with a clearly stated deviation from the test method included in results (explicitlyindicate temperatures as tested).8. Procedure8.1 All associated instrumentation shall be calibrated or verified or both to the manufacturers specification b
31、efore testing. Flowconditions shall be stable for a minimum of three system volume equivalents (residence time) before commencement of datacollection.NOTE 2Calibration procedures for instrumentation used may vary depending on the measurement tool used and manufacturer recommendations. Thisis accepta
32、ble as long as measurements are ensured with accuracy and tolerances stated in 7.1.2.8.2 Manual MeasurementsManual measurements of flow and of elevation shall be collected in accordance with 7.1.2 andreported as follows:8.2.1 The system shall be at stabilized conditions of flow for a minimum of 5 mi
33、n before measurement.8.2.2 Each data point shall consist of the average of three sets of measurements.C1745/C1745M 1828.2.3 Each set of measurements shall be taken at an interval of 5 min 6 30 s from the previous set.8.2.4 Each set of measurements shall consist of three discrete measurements taken i
34、n rapid succession with a maximum totalmeasurement time of 60 s.8.2.5 The average of the nine discrete measurements collected in the three sets shall be recorded as the value for that data point.8.2.6 If the readings are outside the acceptable tolerance, the flow shall be stabilized and the test rep
35、eated after the completedstabilization period.8.3 Computerized MeasurementsData recording using a computerized DA system is preferred over manual measurements sothat data are continuously recorded throughout the test, and the data have increased accuracy when coupled with calibrated flowmeters and D
36、P cells. At a minimum, flow and elevation measurements shall be averaged and recorded every 30 s throughout theduration of test. If the readings are outside the acceptable tolerance, the flow shall be stabilized and the test repeated after thecompleted stabilization period.9. Report9.1 A scaled diag
37、ram including flow meter type and location shall be included with the reported results.9.2 The temperature range over which the test was conducted shall be reported.9.3 Head loss, as well as a loss coefficient (K) of the test unit, shall be reported by using the energy equation between upstreamand d
38、ownstream of the unit:hl5Shu1Vu22gD 2Shd1Vd22gD (1)where:hl = device head loss,hu = measured pressure head or water elevation in the upstream pipe,hd = measured pressure head or water elevation in the downstream pipe,g = gravitational constant, andVu and Vd = calculated average flow velocities in th
39、e upstream and downstream pipes at the tap locations, respectively.9.3.1 Note that, according to 7.1.1, hu and hd are measured pressure heads or water elevations from the same datum.10. Precision and Bias10.1 The precision and bias of this test method will be available within five years.11. Keywords
40、11.1 accuracy; bypass flow; calibration; flow; head loss; hydraulic capacity; orifice; slope; velocity; velocity head (head); weirASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard a
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