ASTM D5716-95(2000)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 5716 – 95 (Reapproved 2000)
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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D4043 Guide for Selection of Aquifer-Test Method in
Determining Hydraulic Properties by Well Techniques
1.1 This test method covers construction and operation of a
D5737 Guide for Methods for Measuring Well Discharge
circular orifice weir for measuring the discharge from a well.
This test method is a part of a series of standards prepared on
3. Terminology
the in situ determination of hydraulic properties of aquifer
3.1 Definitions:
systems by single- or multiple-well tests. Selection of a well
3.1.1 circular orifice weir—a circular restriction in a pipe
discharge measurement test method is described in Guide
thatcausesbackpressurethatcanbemeasuredinapiezometer
D5737.
tube. Also called orifice tube and orifice meter.
1.2 This test method is common to a number of aquifer test
3.1.2 control well—awellbywhichtheheadandflowinthe
methods and to evaluation of well and pump performance.
aquifer is changed, by pumping, injection, or imposing a
1.3 Limitations—This test method is limited to the descrip-
change of head.
tion of a method common to hydraulic engineering for the
3.1.3 discharge—orrateofflow,isthevolumeofwaterthat
purpose of ground water discharge measurement in temporary
passes a particular reference section in a unit of time.
or test conditions.
3.2 For definitions of other terms used in this guide, see
1.4 Muchoftheinformationpresentedinthistestmethodis
Terminology D653.
basedonworkperformedbytheCivilEngineeringDepartment
3.3 Symbols:Symbols and Dimensions:
of Purdue University during the late 1940s. The essentials of
3.3.1 A—orifice plate open area [ L ].
that work have been presented in a pamphlet prepared by
2 3.3.2 C—coefficient of discharge for the orifice [nd].
Layne-Bowler, Inc. and updated by LayneWestern Company,
−2
3.3.3 g—acceleration due to gravity [ LT ].
Inc.
3.3.4 h—head in manometer [ L].
1.5 The values stated in inch-pound units are to be regarded
3 −1
3.3.5 Q—control well discharge [ L T ].
as the standard. The SI units given in parentheses are for
3.3.6 o—orifice diameter [ L].
information only.
3.3.7 d—pipe inside diameter [ L].
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 This test method involves pumping a control well at a
priate safety and health practices and determine the applica-
constant or variable rate for a given period of time. Discharge
bility of regulatory limitations prior to use.
is through an orifice weir that allows determination of the
2. Referenced Documents discharge rate.
4.2 This test method provides design information for con-
2.1 ASTM Standards:
struction of an orifice weir. It also describes setup, operation,
D653 Terminology Relating to Soil, Rock, and Contained
4 inspection, calculation of discharge, and reporting.
Fluids
5. Significance and Use
5.1 Many mathematical equations for determining aquifer
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
RockandisthedirectresponsibilityofSubcommitteeD18.21onGroundWaterand
properties based on controlled field tests utilizing a single or
Vadose Zone Investigations.
multiple-pumping wells include a dependent variable, termed
Current edition approved April 15, 1995. Published August 1995.
discharge, and generally designated as Q. Equations have been
Measurement of Water Flow Through Pipe Orifice With Free Discharge,
Bulletin 501, Layne-Bowler, Inc., Mission, KS, 1958. developed for constant and variable discharge. Those for
Measurement of Water Flow Through Pipe Orifice With Free Discharge,
variable discharge may specify regularly increasing, or regu-
Layne-Western Company, Inc., Mission, KS, 1988.
4 larly decreasing, or randomly varying discharge rate.
Annual Book of ASTM Standards, Vol 04.08.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5716
FIG. 1 Construction of a Circular Orifice Weir
5.2 Aquifer testing has been conducted for the purposes of theplatewillbevertical.Theboreofthepipeshouldbesmooth
production and pressure relief well design and water resource and free of any obstruction that might cause abnormal turbu-
assessment. Production wells are used for public and industrial lence.
water supplies, hydraulic controls, and ground water capture.
6.1.3 Manometer—The discharge pipe wall is tapped mid-
Pressure relief wells are for hydraulic controls. Test wells are
way between the top and bottom with a ⁄8-in. (3.17 mm) or
for the purpose of water resource assessment.
⁄4-in. (6.35 mm) hole exactly 24 in. (609 mm) from the orifice
5.3 Discharge must also be known for certain methods to
plate. The manometer should be a distance of at least ten
evaluate well and pump performance.
discharge pipe diameters from the gate valve used to control
pipe flow.Any burrs inside the pipe resulting from the drilling
6. Apparatus
or tapping of the hole should be filed off. A nipple is screwed
6.1 Construction of a Circular Orifice Weir—Aconstruction
into the tapped hole. The nipple must not protrude inside the
diagram of a circular orifice weir is presented in Fig. 1. The
discharge pipe. A clear plastic tube 4 or 5 ft (1.2 or 1.5 mm)
circularorificeisaholelocatedinthecenterofaplateattached
long is connected at one end to the nipple.Ascale is fastened
to a straight horizontal length of discharge pipe. The pipe is at
to a support so that the vertical distance from the center of the
least 6 ft (1.8 m) in length.Twenty-four inches (609 mm) from
discharge pipe up to the water level in the manometer can be
the end plate and at least 4 ft (1.2 m) from the other end of the
measured. Alternately, a u-tube manometer or pressure trans-
discharge pipe, a manometer is attached to the discharge pipe
ducer may be used. During a test the manometer must be free
so that the head in the discharge pipe can be measured. of air bubbles.
6.1.1 Orifice Plate—The orifice is a round hole with clean,
6.2 The water level in the manometer indicates the pressure
square edges in the center of a circular steel plate. The plate
headintheapproachpipewhenwaterisbeingpumpedthrough
must be a minimum of ⁄16 in. (1.59 mm) thick around the
theorifice.Foranygivensizeoforificedischargepipe,therate
circumference of the hole. The remaining thickness of the
of flow through the orifice varies with the pressure head as
orifice should be chamfered to 45° and with the chamfered
measured in this manner. Table 1 presents the flow in gallons
edge down stream.
per minute (gpm) for various combinations of orifice and pipe
6.1.2 Discharge Pipe—The discharge pipe must be straight
diameters.
and level for a distance of at least 6 ft (1.8 m) before the water
6.3 The diameter of the orifice should be less than 80% of
reaches the orifice plate. This approach channel should be
the inside diameter of the approach channe
...