ASTM D5716-95(2006)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D5716 −95(Reapproved 2006)
Standard Test Method for
Measuring the Rate of Well Discharge by Circular Orifice
Weir
This standard is issued under the fixed designation D5716; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method covers construction and operation of a 2.1 ASTM Standards:
circular orifice weir for measuring the discharge from a well. D653Terminology Relating to Soil, Rock, and Contained
This test method is a part of a series of standards prepared on Fluids
the in situ determination of hydraulic properties of aquifer D5737Guide for Methods for Measuring Well Discharge
systems by single- or multiple-well tests. Selection of a well
3. Terminology
discharge measurement test method is described in Guide
D5737. 3.1 Definitions:
3.1.1 circular orifice weir—a circular restriction in a pipe
1.2 This test method is common to a number of aquifer test
thatcausesbackpressurethatcanbemeasuredinapiezometer
methods and to evaluation of well and pump performance.
tube. Also called orifice tube and orifice meter.
1.3 Limitations—This test method is limited to the descrip-
3.1.2 control well—awellbywhichtheheadandflowinthe
tion of a method common to hydraulic engineering for the
aquifer is changed, by pumping, injection, or imposing a
purpose of groundwater discharge measurement in temporary
change of head.
or test conditions.
3.1.3 discharge—or rate of flow, is the volume of water that
1.4 Muchoftheinformationpresentedinthistestmethodis
passes a particular reference section in a unit of time.
basedonworkperformedbytheCivilEngineeringDepartment
3.2 For definitions of other terms used in this guide, see
of Purdue University during the late 1940s. The essentials of
Terminology D653.
that work have been presented in a pamphlet prepared by
Layne-Bowler, Inc. and updated by LayneWestern Company,
3.3 Symbols and Dimensions:
Inc.
3.3.1 A—orifice plate open area [ L ].
1.5 The values stated in inch-pound units are to be regarded
3.3.2 C—coefficient of discharge for the orifice [nd].
−2
as the standard. The SI units given in parentheses are for
3.3.3 g—acceleration due to gravity [ LT ].
information only.
3.3.4 h—head in manometer [ L].
1.6 This standard does not purport to address all of the
3 −1
3.3.5 Q—control well discharge [ L T ].
safety concerns, if any, associated with its use. It is the
3.3.6 o—orifice diameter [ L].
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3.3.7 d—pipe inside diameter [ L].
bility of regulatory limitations prior to use.
4. Summary of Test Method
4.1 This test method involves pumping a control well at a
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
constant or variable rate for a given period of time. Discharge
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
is through an orifice weir that allows determination of the
Vadose Zone Investigations.
Current edition approved Sept. 15, 2006. Published November 2006. Originally
discharge rate.
approved in 1995. Last previous edition approved in 2000 as D5716–95(2000).
DOI: 10.1520/D5716-95R06.
2 4
Measurement of Water Flow Through Pipe Orifice With Free Discharge, For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Bulletin 501, Layne-Bowler, Inc., Mission, KS, 1958. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Measurement of Water Flow Through Pipe Orifice With Free Discharge, Standards volume information, refer to the standard’s Document Summary page on
Layne-Western Company, Inc., Mission, KS, 1988.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5716−95 (2006)
4.2 This test method provides design information for con- to a straight horizontal length of discharge pipe. The pipe is at
struction of an orifice weir. It also describes setup, operation, least 6 ft (1.8 m) in length.Twenty-four inches (609 mm) from
inspection, calculation of discharge, and reporting. the end plate and at least 4 ft (1.2 m) from the other end of the
discharge pipe, a manometer is attached to the discharge pipe
5. Significance and Use
so that the head in the discharge pipe can be measured.
5.1 Many mathematical equations for determining aquifer 6.1.1 Orifice Plate—The orifice is a round hole with clean,
square edges in the center of a circular steel plate. The plate
properties based on controlled field tests utilizing a single or
multiple-pumping wells include a dependent variable, termed must be a minimum of ⁄16 in. (1.59 mm) thick around the
circumference of the hole. The remaining thickness of the
discharge, and generally designated as Q. Equations have been
developed for constant and variable discharge. Those for orifice should be chamfered to 45° and with the chamfered
edge down stream.
variable discharge may specify regularly increasing, or regu-
larly decreasing, or randomly varying discharge rate. 6.1.2 Discharge Pipe—The discharge pipe must be straight
FIG. 1 Construction of a Circular Orifice Weir
5.2 Aquifer testing has been conducted for the purposes of and level for a distance of at least 6 ft (1.8 m) before the water
production and pressure relief well design and water resource
reaches the orifice plate. This approach channel should be
assessment. Production wells are used for public and industrial longer if possible. The end of the pipe must be cut squarely so
water supplies, hydraulic controls, and groundwater capture.
theplatewillbevertical.Theboreofthepipeshouldbesmooth
Pressure relief wells are for hydraulic controls. Test wells are and free of any obstruction that might cause abnormal turbu-
for the purpose of water resource assessment.
lence.
6.1.3 Manometer—The discharge pipe wall is tapped mid-
5.3 Discharge must also be known for certain methods to
way between the top and bottom with a ⁄8-in. (3.17 mm) or
evaluate well and pump performance.
⁄4-in. (6.35 mm) hole exactly 24 in. (609 mm) from the orifice
6. Apparatus plate. The manometer should be a distance of at least ten
discharge pipe diameters from the gate valve used to control
6.1 Construction of a Circular Orifice Weir—Aconstruction
5 pipe flow.Any burrs inside the pipe resulting from the drilling
diagram of a circular orifice weir is presented in Fig. 1. The
or tapping of the hole should be filed off. A nipple is screwed
circularorificeisaholelocatedinthecenterofaplateattached
into the tapped hole. The nipple must not protrude inside the
discharge pipe. A clear plastic tube 4 or 5 ft (1.2 or 1.5 mm)
5 long is connected at one end to the nipple. A scale is fastened
Driscoll,F.G., Ground Water and Wells,JohnsonDivision,St.Paul,MN,1986,
pp. 537–541. to a support so that the vertical distance from the center of the
D5716−95 (2006)
discharge pipe up to the water level in the manometer can be Q 5 AVC (1)
measured. Alternately, a u-tube manometer or pressure trans-
where:
ducer may be used. During a test the manometer must be free
Q = the flow per unit time,
of air bubbles.
A = the area of the orifice,
6.2 The water level in the manometer indicates the pressure
V = the velocity of flow through the orifice, and
headintheapproachpipewhenwaterisbeingpumpedthrough
C = the coefficient of discharge fo
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