ISO 13693-2:2015

INTERNATIONAL ISO
STANDARD 13693-2
First edition
2015-02-15
Irrigation equipment — Safety devices
for chemigation —
Part 2:
Chemigation valve assemblies from
DN 75 (3”) to DN 350 (14”)
Matériel d’irrigation — Dispositifs de sécurité pour l’application de
produits chimiques par irrigation —
Partie 2: Installations de vannes pour application de produits
chimiques par irrigation de DN 75 (3”) à DN 350 (14”)
Reference number
ISO 13693-2:2015(E)
©
ISO 2015

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ISO 13693-2:2015(E)

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© ISO 2015
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ii © ISO 2015 – All rights reserved

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ISO 13693-2:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Design considerations . 2
4.1 General requirements . 2
4.2 Specific requirements . 3
5 Performance requirements . 4
5.1 General . 4
5.2 Permissible deviations of measuring devices . 4
5.3 Mechanical strength of valve body assembly and components . 4
5.3.1 Resistance to internal pressure . 4
5.3.2 Test methods . 5
5.4 Low pressure drain valve . 5
5.5 Hydraulic characteristics . 5
5.6 Vacuum relief valve . 6
5.7 Elevated temperature tests . 6
5.8 Endurance . 6
5.8.1 Requirements . 6
5.8.2 Tests . 6
5.9 Acoustic test . 6
6 Conformity assessment . 6
6.1 General . 6
6.2 Type tests . 7
6.3 Control of production process and quality system . 7
7 Marking, technical documents, and packaging. 7
7.1 Marking . 7
7.2 Technical documents . 7
7.3 Packaging . 7
Bibliography . 8
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ISO 13693-2:2015(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 meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 18, Irrigation and drainage equipment and systems.
ISO 13693 consists of the following parts, under the general title Irrigation equipment —Safety devices
for chemigation:
— Part 1: Small plastics valves for chemington
— Part 2: Chemigation valve assemblies from DN 75 (3”) to DN 350 (14”)
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ISO 13693-2:2015(E)

Introduction
Chemigation is the practice of injecting chemicals into irrigation water for the purpose of distributing
the chemicals onto crops. During the course of this activity, under certain hydraulic conditions, the
chemicals being injected can migrate upstream into a well or other pressurized water supply and
pollute that water source. A chemigation valve assembly has been developed to meet this need. The
chemigation valve assembly is designed to meet the specific need and performance requirements as
required to prohibit the migration of injected chemicals into irrigation wells, thereby polluting ground
water supplies.
This part of ISO 13693 applies to a mainline check valve assembly in sizes from DN 75 (3”) to DN 350
(14”), with related components, that is designed to permit full flow in the operational mode and stop
backflow (back siphonage or back pressure) when the pipeline shuts down. The potential for backflow
from back siphonage occurs as water tumbles back down the column pipe when the pump shuts down.
The potential for backflow occurs when a positive pressure exists on the downstream end of the valve.
The valve obturator is forced to the closed position by a pre-tensioned spring. A resilient cover on the
obturator helps to seal the valve against very low pressures.
This chemigation valve assembly is included in a technical report (to be written) that specifies a complete
chemigation safety system. This system features a chemical tank (fertilizers and chemicals), a chemical
pump (positive displacement or Venturi), check valves, and interlocking safety shutdown controls. The
system is designed to keep irrigation water from flooding the chemical tank and to shut the chemical
system down when the irrigation pump shuts down or the irrigation system pressure has been reduced
to a level where the injected chemical is not being uniformly distributed to the field. The functional
requirements of the chemigation valve could possibly be provided by valves of a different design. The
valve is not designed for use in potable water systems.
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INTERNATIONAL STANDARD ISO 13693-2:2015(E)
Irrigation equipment — Safety devices for chemigation —
Part 2:
Chemigation valve assemblies from DN 75 (3”) to DN 350
(14”)
1 Scope
This part of ISO 13693 specifies the construction and performance requirement and test methods for
metal-bodied chemigation valves with water at temperatures not exceeding 50 °C, which might contain
fertilizers and chemicals of the types and concentration used in agriculture.
The valve is designed to prohibit backflow caused by either back pressure or back siphonage. It is
not designed for use in potable water systems. It is not to be confused with other forms of backflow
prevention devices including pressure vacuum breakers, double check valves, reduced pressure zone
valves, or goose neck loops. This part of ISO 1
...