ISO 9635-4:2006

INTERNATIONAL ISO
STANDARD 9635-4
First edition
2006-11-15


Agricultural irrigation equipment —
Irrigation valves —
Part 4:
Air valves
Matériel agricole d'irrigation — Vannes d'irrigation —
Partie 4: Vannes de purge d'air





Reference number
ISO 9635-4:2006(E)
©
ISO 2006

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ISO 9635-4:2006(E)
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ISO 9635-4:2006(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Design requirements . 2
5 Performance requirements . 2
5.1 Mechanical strength . 2
5.2 Watertightness . 2
5.3 Airflow characteristics . 3
5.4 Resistance to chemicals and fertilizers. 3
5.5 Endurance . 4
6 Conformity assessment . 4
6.1 General. 4
6.2 Type tests . 4
6.3 Control of production process and quality system . 4
7 Marking . 5
8 Packaging . 5
Annex A (normative) Test method for airflow characteristics of valves with air release function. 6
Annex B (normative) Test method for airflow characteristics of valves with air intake function. 8
Annex C (normative) Test method for endurance of valves with air intake and/or air release
functions. 10
Bibliography . 11

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ISO 9635-4:2006(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 9635-4 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 first edition of ISO 9635-4, together with ISO 9635-1, ISO 9635-2, ISO 9635-3 and ISO 9635-5, cancels
and replaces ISO 9635:1990, of which it constitutes a technical revision.
ISO 9635 consists of the following parts, under the general title Agricultural irrigation equipment — Irrigation
valves:
⎯ Part 1: General requirements
⎯ Part 2: Isolating valves
⎯ Part 3: Check valves
⎯ Part 4: Air valves
⎯ Part 5: Control valves

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INTERNATIONAL STANDARD ISO 9635-4:2006(E)

Agricultural irrigation equipment — Irrigation valves —
Part 4:
Air valves
1 Scope
This part of ISO 9635 specifies construction and performance requirements and test methods for air valves,
intended for operation in irrigation systems with water at temperatures not exceeding 60 °C, which can contain
fertilizers and other chemicals of the types and concentrations used in agriculture.
It is applicable to hydraulically operated air irrigation valves of DN 15 (1/2 inch) diameter or greater,
designed to be directly operated, i.e. the force is applied to the obturator by the float, either directly or via a
mechanical linkage. The valves can be operated by a force applied through an adjustable pilot valve.
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 9635-1:2006, Agricultural irrigation equipment — Irrigation valves — Part 1: General requirements
ISO 9635-2:2006, Agricultural irrigation equipment — Irrigation valves — Part 2: Isolating valves
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9635-1 and the following apply.
3.1
air valve
float-type purger
self-operating float-type valve designed for the evacuation of air from, or the ingress of air into, water
pipelines.
NOTE Such valves can be single-float or double-float and can fulfil one or more or the following functions: air release,
air intake, air venting.
3.2
air release function
discharge of an air volume from a water pipeline
3.3
air intake function
vacuum relief function
admittance of an air volume into a water pipeline
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ISO 9635-4:2006(E)
3.4
air venting function
continuous acting air vent function
purging of entrapped air from a water pipeline in service under pressure
4 Design requirements
Air valves and float-type purgers shall be designed in accordance with ISO 9635-1:2006, Clause 4. In
addition, these valves may be fitted with an integrated isolating device, which shall be in accordance with
ISO 9635-2.
5 Performance requirements
All tests are to be performed on the valve as delivered to the test facility.
5.1 Mechanical strength
5.1.1 Resistance of shell and all pressure-containing components to internal pressure
Requirements and testing shall be in accordance with ISO 9635-1:2006, 5.1.1. For double-float valves, the
obturators may be tested simultaneously or separately.
5.1.2 Resistance of obturator to differential pressure
Tested within 5.1.1.
5.1.3 Resistance of valves to bending
Not applicable. However, bending resistance may be an optional requirement for air valves, if bending
resistance is specified by the customer
5.1.4 Resistance of valves to operating loads
Not applicable, except for any integrated isolating device, which shall be in accordance with
ISO 9635-2:2006, 5.1.4.
5.2 Watertightness
5.2.1 Watertightness of shell and all pressure-containing components
5.2.1.1 Internal pressure
The requirement of watertightness to internal pressure is fulfilled by conformance to 5.1.1.
5.2.1.2 External pressure
Not applicable, except for any integrated isolating device, which shall be in accordance with
ISO 9635-2:2006, 5.2.1.2.
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ISO 9635-4:2006(E)
5.2.2 Seat tightness
5.2.2.1 Seat tightness at high pressure
Requirements and testing shall be in accordance with ISO 9635-1:2006, 5.2.2.1.The test fluid shall be water.
The leakage rate shall be rate A. For a type test, the test duration shall not be less than 10 min. For
double-float valves, the obturators may be tested simultaneously or separately.
5.2.2.2 Seat tightness at low pressure
Requirements and testing shall be in accordance with ISO 9635-1:2006, 5.2.2.2. The test fluid shall be water.
The leakage rate shall be rate A. For a type test, the test duration shall not be less than 10 min. For
double-float valves, the obturators may be tested simultaneously or separately.
5.2.3 Maximum operating torque (MOT) for operation and
...