ISO 7714:2018
(Main)Agricultural irrigation equipment — Volumetric valves — General requirements and test methods
Agricultural irrigation equipment — Volumetric valves — General requirements and test methods
This document 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.
Matériel agricole d'irrigation — Vannes volumétriques — Exigences générales et méthodes d'essai
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7714
Fifth edition
2018-05
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 7714:2018(E)
©
ISO 2018
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ISO 7714:2018(E)
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© ISO 2018
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ii © ISO 2018 – All rights reserved
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ISO 7714:2018(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 . 4
6.3 Metrological requirements . 5
6.3.1 General. 5
6.3.2 Class 1, Class 2 and Class 3 — Sizes DN16, DN20 and DN25 . 5
6.3.3 Class 1 and Class 2 — Sizes DN40 to DN300 . 5
6.3.4 Overload flow rate (q ) . 6
V4
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 . 6
7.3.1 Pattern approval tests . 6
7.3.2 Thermal preconditioning . 7
7.4 Test of resistance to hydrostatic pressure . 7
7.5 Test of manual opening and closing. 7
7.5.1 Non-serial volumetric valves . 7
7.5.2 Serial volumetric valves (single outlet, single outlet “skip over”, and dual outlet) 7
7.6 Tests of accuracy . 8
7.6.1 General. 8
7.6.2 Flow rates and maximum permissible error for accuracy tests . 8
7.7 Pressure loss . 9
7.7.1 Requirement . 9
7.7.2 Test procedure . 9
7.8 Endurance tests . 9
7.8.1 Endurance flow conditioning . 9
7.8.2 Accuracy tests after endurance conditioning . 9
7.8.3 Endurance of operating mechanism .10
8 Information to be supplied by the manufacturer .10
Annex A (informative) Quality of irrigation water .12
Bibliography .13
© ISO 2018 – All rights reserved iii
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ISO 7714:2018(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html
This document 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 fifth edition cancels and replaces the fourth edition (ISO 7714:2008), which has been technically
revised.
The main changes are the following:
— addition of a paragraph to 6.1 that metering valves with metrological characteristics shall comply
with the relevant standard for meters for irrigation water;
— addition of ISO 16399 to the Normative references.
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INTERNATIONAL STANDARD ISO 7714:2018(E)
Agricultural irrigation equipment — Volumetric valves —
General requirements and test methods
1 Scope
This document 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 documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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
ISO 16399:2014, Meters for irrigation water
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
volumetric valve
valve capable of automatically delivering preset volumes of water within the range of flow rates, as a
result of measuring the volume of water flowing through the valve
3.2
serial volumetric valve
volumetric valve (3.1) designed to operate in a sequence of volumetric valves
3.2.1
single outlet serial volumetric valve
serial volumetric valve (3.2) 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
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ISO 7714:2018(E)
3.2.2
single outlet “skip over” serial volumetric valve
serial volumetric valve (3.2) 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
3.2.3
dual outlet serial volumetric valve
serial volumetric valve (3.2) 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 (3.1) designed to operate alone
3.4
permanent flow rate
q
V3
highest flow rate within the rated operating conditions at which the meter is designed to operate in a
satisfactory manner within the maximum permissible error
3.5
overload flow rate
q
V4
highest flow rate at which the water meter is designed to operate 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 (3.1) is designed to operate within the maximum
permissible error
3.7
range of flow rate
flow rate between the minimum flow rate (3.6) and the overload flow rate (3.5), inclusive of limits
3.8
range of working flow rate
flow rate between the minimum flow rate (3.6) and the permanent flow rate (3.4), inclusive of limits
3.9
relative error
ε
difference between measured and actual volume divided by actual volume, expressed as a percentage
3.10
maximum working pressure
highest pressure immediately upstream from a device recommended by the manufacturer to ensure
continuous operation and functionality
3.11
minimum working pressure
lowest water pressure at the inlet to a volumetric valve (3.1) at which it operates satisfactorily and
performs the mechanical and hydraulic functions as specified by the manufacturer
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ISO 7714:2018(E)
3.12
range of working pressures
pressures between and including the minimum working pressure (3.11) and the maximum working
pressure (3.10)
3.13
nominal pressure
pressure numerical designation equal to the maximum working pressure (3.10) specified by the
manufacturer
3.14
accuracy
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.
4.2.2 Serial volumetric valve:
— single outlet serial volumetric valve;
— single outlet “skip over” serial volumetric valve;
— dual outlet serial volumetric valve.
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ISO 7714:2018(E)
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;
— perman
...
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