1、Designation: D5716/D5716M 15Standard Test Method forMeasuring the Rate of Well Discharge by Circular OrificeWeir1This standard is issued under the fixed designation D5716/D5716M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the
2、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. Scope*1.1 This test method covers construction and operation of acircular orifice weir for measuring the discharge from
3、 a well.This test method is a part of a series of standards prepared onthe in situ determination of hydraulic properties of aquifersystems by single- or multiple-well tests. Selection of a welldischarge measurement test method is described in GuideD5737.1.2 The discharge rate determined by this test
4、 method iscommonly used for a number of aquifer test methods and toprovide information for the evaluation of well and pumpperformance.1.3 LimitationsThis test method is limited to the descrip-tion of a method common to hydraulic engineering for thepurpose of groundwater discharge measurement in temp
5、oraryor test conditions.1.4 Much of the information presented in this test method isbased on work performed by the Civil Engineering Departmentof Purdue University during the late 1940s. The essentials ofthat work have been presented in a pamphlet prepared byLayne-Bowler, Inc.2and updated by Layne W
6、estern Company,Inc.31.5 All observed and calculated values shall be conform tothe guidelines for significant digits and rounding established inPractice D6026.1.5.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard. In
7、addition they are representative of thesignificant digits that should generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or reduc
8、e significant digits of reported data to becommensurate with these considerations. It is beyond the scopeof this document to consider significant digits sused analysismethods for engineering design.1.6 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as sta
9、ndard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.7 This standard does not purport to address all of thesafety concerns, if any, a
10、ssociated 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.2. Referenced Documents2.1 ASTM Standards:4D653 Terminology Relating to Soil, Rock, and Contained
11、FluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD5737 Guide for Methods for Measuring Well DischargeD6026 Practice for Using Significant Digits in GeotechnicalData2.2 Other Documents:GWPD 10
12、Estimating discharge from a pumping well by useof a circular orifice weir, United States Geological Survey3. Terminology3.1 Definitions:3.1.1 For definitions of common technical terms used in thisstandard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:1This test method
13、 is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved Nov. 1, 2015. Published December 2015. Originallyapproved in 1995. Last previous edition approved in 2006 as D
14、571695(2006),which was withdrawn July 2015 and reinstated in November 2015. DOI: 10.1520/D5716-15.2Measurement of Water Flow Through Pipe Orifice With Free Discharge,Bulletin 501, Layne-Bowler, Inc., Mission, KS, 1958.3Measurement of Water Flow Through Pipe Orifice With Free Discharge,Layne-Western
15、Company, Inc., Mission, KS, 1988.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes sectio
16、n appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 circular orifice weira circular restriction in a pipethat causes back pressure that can be measured in a piezometertube.3.2.1.1 DiscussionAlso
17、called orifice tube and orificemeter.3.3 Symbols and Dimensions Used in this Standard:3.3.1 Aorifice plate open area L2.3.3.2 Ccoefficient of discharge for the orifice nd.3.3.3 gacceleration due to gravity LT2.3.3.4 hhead in manometer L.3.3.5 Qcontrol well discharge L3T1.3.3.6 oorifice diameter L.3.
18、3.7 dpipe inside diameter L.4. Summary of Test Method4.1 This test method involves pumping a control well at aconstant or variable rate through a circular orifice weir for agiven period of time. Discharge is through an orifice weir thatallows determination of the discharge rate.4.25. Significance an
19、d Use5.1 This test method provides design information for con-struction of an orifice weir. It also describes setup, operation,inspection, calculation of discharge, and reporting. The accu-racy of a circular weir decreases at low flows. The use of acircular orifice weir requires a constant flow velo
20、city over theperiod of measurement. The results may be affected by thepiezometers distance from the orifice plate. This equipmentmay not be appropriate for measuring flows on small wells, orwells with limited recharge.5.2 Aquifer testing has been conducted for the purposes ofproduction and pressure
21、relief well design and water resourceassessment. Production wells are used for public and industrialwater supplies, hydraulic controls, and groundwater capture.Pressure relief wells are for hydraulic controls. Test wells arefor the purpose of water resource assessment.5.3 Discharge must also be know
22、n for certain methods toevaluate well and pump performance.NOTE 1Practice D3740 provides evaluation factors for the activitiesin this standard. The quality of the result produced by this standard isdependent on the competence of the personnel performing it and thesuitability of the equipment and fac
23、ilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on man
24、y factors; Practice D3740provides a means of evaluating some of those factors.6. Apparatus6.1 Construction of a Circular Orifice WeirAconstructiondiagram of a circular orifice weir is presented in Fig. 1.5Thecircular orifice is a hole located in the center of a plate attachedto a straight horizontal
25、 length of discharge pipe. The pipe is atleast 1.8 m 6 ft in length. Approximately 600 mm 24 in.from the end plate and at least 1.2 m 4 ft from the other endof the discharge pipe, a piezometer is attached to the dischargepipe so that the head in the discharge pipe can be measured.5Driscoll, F. G., G
26、round Water and Wells, Johnson Division, St. Paul, MN, 1986,pp. 537541.FIG. 1 Construction of a Circular Orifice Weir5D5716/D5716M 1526.1.1 Orifice PlateThe orifice is a round hole with clean,square edges in the center of a circular steel plate. The platemust be a minimum of 1.6 mm 116 in. thick aro
27、und thecircumference of the hole. The remaining thickness of theorifice should be chamfered to 45 and with the chamferededge down stream.6.1.2 Discharge PipeThe discharge pipe must be straightand level for a distance of at least 1.8 m 6 ft before the waterreaches the orifice plate. This approach cha
28、nnel should belonger if possible. The end of the pipe must be cut squarely sothe plate will be vertical.The bore of the pipe should be smoothand free of any obstruction that might cause abnormal turbu-lence.6.1.3 PiezometerThe discharge pipe wall is tapped mid-way between the top and bottom witha3mm
29、18-in. or 6 mm14-in. hole exactly 600 mm 24 in. from the orifice plate. Themanometer should be a distance of at least ten discharge pipediameters from the gate valve used to control pipe flow. Anyburrs inside the pipe resulting from the drilling or tapping ofthe hole should be filed off.Anipple is s
30、crewed into the tappedhole. The nipple must not protrude inside the discharge pipe.Aclear plastic tube 1.2 to 1.5 m 4 or 5 ft long is connected atone end to the nipple.Ascale is fastened to a support so that thevertical distance from the center of the discharge pipe up to thewater level in the manom
31、eter can be measured. Alternately, au-tube manometer or pressure transducer may be used. Duringa test the manometer must be free of air bubbles.6.2 The diameter of the orifice should be less than 80 % ofthe inside diameter of the approach channel pipe.7. Procedure7.1 Set up the apparatus as shown in
32、 Fig. 1 and Fig. 2. Theapparatus should be set up so that the orifice pipe is horizontaland the discharge is unimpeded. Use a combination of pipe andorifice diameter so that the anticipated head will be at leastthree times the diameter of the orifice. The orifice plate must bevertical and centered i
33、n the discharge pipe.7.2 Equipment should be inspected to minimize the poten-tial of wear, damage or misuse causing increased head loss thatwill bias results.7.3 Initiate flow through the discharge pipe. Check that themanometer is free of air bubbles. Record the manometer level.Using Table 1 and Tab
34、le 2 for the appropriate pipe and orificesize, read the discharge.8. Calculation8.1 Calculate the flow through the orifice using the basicequation:Q 5 AVC (1)where:Q = the flow per unit time,A = the area of the orifice,V = the velocity of flow through the orifice, andC = the coefficient of discharge
35、 for the orifice.The velocity of the water at the orifice consists of its velocityin the approach channel plus the additional velocity headcreated by the pressure drop that occurs between the connec-tion for the manometer and the orifice. Because the waterdischarges at atmospheric pressure, the pres
36、sure head indicatedby the manometer can be converted to the velocity if friction inthe pipe is neglected.FIG. 2 The Coefficient of Discharge, C, in the Orifice-Weir Equation3D5716/D5716M 1538.2 Relate the velocity to the head in the manometer by theequation:V 5 =2gh (2)where:V = velocity,g = acceler
37、ation due to gravity, andh = the height of water in the manometer.To compute the actual velocity through the orifice, the valueof V from Eq 2 must be added to the velocity in the dischargepipe approach, and the sum of these must be corrected by twofactors. One correction is for the contraction of th
38、e jet streamjust outside of the orifice, and the other is for the suddenchange in cross-sectional area of flow, which is controlled bythe size of the orifice relative to the size of the approachchannel. The approach velocity and the two correction factorsare combined into a single factor, C, whose v
39、alue varies withthe ratio of the orifice inside diameter to the approach-pipeinside diameter as presented in Fig. 2.8.3 The equation for flow through the orifice is:TABLE 1 Flow Rates through Circular Orifice Weirs5(SI)NOTE 1Flow rates indicated below the line are more exact than those above the lin
40、e because the head developed in the piezometer tube for particularpipe and orifice diameters is large enough to ensure the accuracy of results obtained from Eq 5.Headof Wa-termm100 mm Pipe 150 mm Pipe 200 mm Pipe 250 mm Pipe 300 mm Pipe 400 mm Pipe64mmOrificeLpm76mmOrificeLpm76mmOrificeLpm102mmOrifi
41、ceLpm102mmOrificeLpm127mmOrificeLpm150mmOrificeLpm150mmOrificeLpm178mmOrificeLpm200mmOrificeLpm150mmOrificeLpm200mmOrificeLpm200mmOrificeLpm250mmOrificeLpm300mmOrificeLpm127 210 340 290 550 500 830 1340 1170 1740 2570 1170 2200 2010 3330 5380150 230 370 310 600 550 910 1480 1290 1890 2800 1230 2420
42、2200 3630 5900175 250 400 330 650 590 980 1590 1400 2040 3140 1330 2610 2350 3940 6360200 260 420 360 690 630 1040 1700 1490 2200 3330 1420 2760 2540 4200 6810230 280 450 380 730 670 1120 1780 1590 2310 3560 1510 2950 2690 4470 7230250 290 480 400 770 700 1170 1890 1670 2420 3750 1590 3100 2840 4690
43、 7610300 320 520 430 840 770 1290 2080 1820 2650 4090 1740 3410 3100 5150 8330350 350 560 475 910 830 1380 2250 1970 2880 4430 1890 3670 3330 5570 9010400 370 600 500 980 890 1480 2400 2100 3070 4730 2010 3940 3560 5940 9620450 390 640 530 1030 950 1570 2560 2230 3260 5040 2120 4160 3780 6320 101805
44、00 420 670 570 1090 1000 1670 2690 2350 3450 5300 2230 4390 3980 6660 10750560 440 700 600 1140 1040 1740 2820 2460 3600 5570 2350 4620 4200 6970 11280635 460 750 640 1220 1120 1860 3010 2610 3860 5900 2500 4920 4470 7420 12040760 510 820 690 1340 1230 2040 3290 2880 4240 6730 2760 5380 4880 8140 13
45、170890 550 890 750 1440 1340 2200 3560 3100 4580 7000 2990 5790 5300 8780 142301020 590 950 800 1530 1400 2350 3780 3330 4880 7500 3180 6210 5640 9390 152201140 620 1010 840 1630 1500 2500 4010 3520 5190 7680 3370 6590 5980 9960 161301270 660 1060 890 1720 1570 2610 4240 3710 5450 8110 3560 6930 632
46、0 10520 170001525 720 1770 980 1890 1720 2880 4660 4090 5980 8860 3900 7610 6930 11500 186201780 780 1320 1060 1990 1850 3070 4850 4320 6470 9580 4200 8210 7460 12420 20100TABLE 2 Flow Rates through Circular Orifice Weirs5NOTE 1Flow rates indicated below the line are more exact than those above the
47、line because the head developed in the piezometer tube for particularpipe and orifice diameters is large enough to ensure the accuracy of results obtained from Eq 5.Head ofWaterin.4-in. Pipe 6-in. Pipe 8-in. Pipe 10-in. Pipe 12-in. Pipe 16-in. Pipe212-in.Orificegpm3-in.Orificegpm3-in.Orificegpm4-in.
48、Orificegpm4-in.Orificegpm5-in.Orificegpm6-in.Orificegpm6-in.Orificegpm7-in.Orificegpm8-in.Orificegpm6-in.Orificegpm8-in.Orificegpm8-in.Orificegpm10-in.Orificegpm12-in.Orificegpm5 55 89 76 145 131 220 355 310 460 680 300 580 530 880 14206 60 97 82 158 144 240 390 340 500 740 325 640 580 960 15607 65
49、105 88 171 156 260 420 370 540 830 350 690 620 1040 16808 69 112 94 182 166 275 450 395 580 880 375 730 670 1110 18009 73 119 100 193 176 295 475 420 610 940 400 780 710 1180 191010 77 126 106 204 186 310 500 440 640 990 420 820 750 1240 201012 85 138 115 223 205 340 550 480 700 1080 460 900 820 1360 220014 92 149 125 241 220 365 595 520 760 1170 500 970 880 1470 238016 98 159 132 258 235 390 635 555 810 1250 530 1040 940 1570 254018 104 168 140 273 250 415 675 590 860 1330 560 1100 1000 1670 269020 110 178 150 288 26
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