ISO 7714:2008
(Main)Agricultural irrigation equipment — Volumetric valves — General requirements and test methods
Agricultural irrigation equipment — Volumetric valves — General requirements and test methods
ISO 7714:2008 specifies general requirements and test methods for volumetric valves able to automatically deliver preset quantities of water. It is applicable to valves actuated by pipeline pressure and flow alone, and which do not need any other, external, source of energy.
Matériel agricole d'irrigation — Vannes volumétriques — Exigences générales et méthodes d'essai
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7714
Fourth edition
2008-09-01
Agricultural irrigation equipment —
Volumetric valves — General
requirements and test methods
Matériel agricole d'irrigation — Vannes volumétriques — Exigences
générales et méthodes d'essai
Reference number
ISO 7714:2008(E)
©
ISO 2008
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ISO 7714:2008(E)
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ii © ISO 2008 – All rights reserved
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ISO 7714:2008(E)
Contents Page
Foreword .iv
1 Scope .1
2 Normative references.1
3 Terms and definitions .1
4 Classification .3
4.1 According to accuracy of cumulative volume counter .3
4.2 According to method of operation as a system of volumetric valves .3
5 Markings.4
6 Technical requirements .4
6.1 General .4
6.2 Threaded and flanged connections.5
6.3 Metrological requirements.5
7 Mechanical, functional and accuracy tests .6
7.1 General .6
7.2 Accuracy of measuring devices .6
7.3 Sampling and minimum acceptance requirements .7
7.4 Test of resistance to hydrostatic pressure.7
7.5 Test of manual opening and closing .8
7.6 Tests of accuracy .8
7.7 Pressure loss .9
7.8 Endurance tests.10
8 Information to be supplied by the manufacturer.11
Annex A (informative) Quality of irrigation water .12
Bibliography.13
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ISO 7714:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 7714 was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 18, Irrigation and drainage equipment and systems.
This fourth edition cancels and replaces the third edition (ISO 7714:2000), which has been technically revised.
iv © ISO 2008 – All rights reserved
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INTERNATIONAL STANDARD ISO 7714:2008(E)
Agricultural irrigation equipment — Volumetric valves —
General requirements and test methods
1 Scope
This International Standard specifies general requirements and test methods for volumetric valves able to
automatically deliver preset quantities of water. It is applicable to valves actuated by pipeline pressure and
flow alone, and which do not need any other, external, source of energy.
NOTE Volumetric valves are typically required to operate correctly with different qualities of irrigation water at a
variety of flow rates and at temperatures between 5 °C and 50 °C.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 7-1, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances
and designation
ISO 9644: Agricultural irrigation equipment — Pressure losses in irrigation valves — Test method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
volumetric valve
valve capable of automatically delivering preset volumes of irrigation water at various flow rates, by measuring
the volume of water flowing through the valve
3.2
serial volumetric valve
volumetric valve designed to operate in a sequence of volumetric valves
3.2.1
single outlet serial volumetric valve
serial volumetric valve with one inlet and one outlet, intended for connection in parallel in a system of
volumetric valves designed to be opened by means of a hydraulic command when preset to the open position
and which, on closing after delivering a preset volume of water, transmits a hydraulic command to the next
volumetric valve in the system to bring it into operation
3.2.2
single outlet “skip over” serial volumetric valve
serial volumetric valve with one inlet and one outlet, intended for connection in parallel in a system of
volumetric valves designed to be opened by means of a hydraulic command when preset to the open position
and which, on closing after delivering a preset volume of water, skips over the next volumetric valve in the
system and transmits a hydraulic command to the second next volumetric valve to bring it into operation
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ISO 7714:2008(E)
3.2.3
dual outlet serial volumetric valve
serial volumetric valve with one inlet and two outlets, normally open when the pressure at the inlet is the
atmospheric pressure and designed so that, when a preset volume of water has passed through the first
outlet, this outlet closes automatically, the second outlet opens automatically and all the flow is passed
through the second outlet to the next volumetric valve in the series
3.3
non-serial volumetric valve
volumetric valve designed to operate alone
3.4
permanent flow rate
q
V3
highest flow rate under normal service conditions at which the volumetric valve can be operated in a
satisfactory manner within the maximum permissible error
3.5
overload flow rate
q
V4
highest flow rate at which the volumetric valve does not exceed the maximum permissible pressure loss and
can be operated for a short period of time within its maximum permissible error, whilst maintaining its
metrological performance when it is subsequently operated under normal service conditions
3.6
minimum flow rate
q
V1
lowest flow rate at which the volumetric valve can be operated within the maximum permissible error
3.7
range of flow rates
flow rates ranging from the minimum flow rate to the overload flow rate, inclusive of limits
3.8
range of working flow rates
flow rates ranging from the minimum flow rate to the permanent flow rate, inclusive of limits
3.9
relative error
ε
error, expressed as a percentage, defined by the equation:
VV−
ia
ε=×100
V
a
where
V is the indicated volume;
i
V is the actual volume.
a
[ISO 4064-3:2005, definition 3.3]
3.10
maximum working pressure
highest water pressure at the inlet to a volumetric valve at which it performs satisfactorily the functions
specified by the manufacturer
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ISO 7714:2008(E)
3.11
minimum working pressure
lowest water pressure at the inlet to a volumetric valve at which it operates satisfactorily and performs the
mechanical and hydraulic functions as specified by the manufacturer
3.12
range of working pressures
all pressures ranging from the minimum working pressure to the maximum working pressure, inclusive of
limits
3.13
nominal pressure
highest pressure at the inlet to a volumetric valve at which the volumetric valve should be operated under
normal service conditions, as specified by the manufacturer
3.14
accuracy
the quality which characterizes the ability of a measuring instrument to give indications approximating to the
true value of the quantity measured
3.15
uncertainty of measurement
parameter associated with the result of a measurement, obtained using an appropriate mathematical formula
which takes into account all sources of error, that characterizes the dispersion of values that could reasonably
be attributed to the measurement result
3.16
pattern approval
certification bestowed by an authorized and accepted body, recognizing that the pattern of a measuring
instrument conforms to the requirements of accepted International Standards
3.17
granulometry
measure of the particle (grain) content of irrigation water, as characterized by size dispersion and total amount
of solids
4 Classification
4.1 According to accuracy of cumulative volume counter
Class 1: volumetric valve containing a control mechanism with a cumulative volume counter and having an
accuracy of volume measurement of ± 2 %, within the range of flow rates.
Class 2: volumetric valve containing a control mechanism with a cumulative volume counter and having an
accuracy of volume measurement of ± 4 %, within the range of flow rates.
Classes 1 and 2 are recommended for water measurement in agricultural irrigation applications.
Class 3: volumetric valve containing a preset volume mechanism but without a cumulative volume counter.
4.2 According to method of operation as a system of volumetric valves
4.2.1 Non-serial volumetric valve.
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ISO 7714:2008(E)
4.2.2 Serial volumetric valve:
⎯ single outlet serial volumetric valve;
⎯ single outlet “skip over” serial volumetric valve;
⎯ dual outlet serial volumetric valve.
NOTE The opening and closing commands of the water in the inlet of the first valve in the system can be either
manual or automatic.
5 Markings
Each volumetric valve shall bear clear and permanent markings including the following information:
⎯ name of manufacturer or the manufacturer’s registered trademark;
⎯ permanent flow rate, q ;
V3
⎯ ratio q /q ;
V3 V1
⎯ serial number;
⎯ arrow indicating the direction of flow;
⎯ arrow indicating the direction of setting of the control device, if necessary;
⎯ nominal pressure;
⎯ for serial volumetric valves, a mark identifying the points of connection for serial operation, which
shall be explained in the manufacturer’s catalogue;
⎯ accuracy class (1, 2 or 3).
6 Technical requirements
6.1 General
All parts of volumetric valves of the same size, type and model intended for disassembly, maintenance and
repair produced by the same manufacturer shall be interchangeable.
All parts of the volumetric valve shall be resistant to chemicals normally used in agriculture in their
conventional concentrations, and shall operate smoothly for the water quality defined in 7.1.
Upon request, the manufacturer shall supply information pertaining to the operation and safety of the valve
with water of purity levels not conventionally found in agriculture, such as corrosive water.
All non-metallic parts of the volumetric valves which are exposed to sunlight shall be protected against
degradation from ultraviolet (UV) radiation under the normal operating conditions of the valve.
Non-metallic parts of the valve which serve as water passages shall be opaque or shall be protected in some
other manner (for instance, by a closed cover) against penetration of light to the water passages.
The flow-control mechanism of the volumetric valve shall allow a means of manual override to stop the flow at
any time, such as returning the setting device to zero.
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ISO 7714:2008(E)
6.2 Threaded and flanged connections
In volumetric valves with threaded ends intended for direct connection to the pipeline, the thread shall comply
with ISO 7-1. Alternatively, other threads may be a
...
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