ISO 9635-2:2014

INTERNATIONAL ISO
STANDARD 9635-2
Second edition
2014-11-15
Agricultural irrigation equipment —
Irrigation valves —
Part 2:
Isolating valves
Matériel agricole d’irrigation — Vannes d’irrigation —
Partie 2: Vannes d’isolation
Reference number
ISO 9635-2:2014(E)
©
ISO 2014

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ISO 9635-2:2014(E)

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© ISO 2014
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ISO 9635-2:2014(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 General . 2
5.2 Mechanical strength . 2
5.3 Watertightness and airtightness. 3
5.4 Hydraulic characteristics . 5
5.5 Resistance to chemicals and fertilizers . 5
5.6 Endurance . 5
6 Conformity assessment . 6
6.1 General . 6
6.2 Type tests . 6
6.3 Control of production process and quality system . 6
7 Marking . 6
8 Packaging . 6
Annex A (normative) Test method for resistance of valves to operating loads .8
Annex B (normative) Torque requirements for gate valves to be operated by ring key and bar .9
Annex C (normative) Test method for operation of valves .10
Annex D (normative) Test method for endurance of valves .11
Annex E (normative) Method for sizing operating element .12
Bibliography .15
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ISO 9635-2:2014(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
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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
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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.
This second edition cancels and replaces the first edition (ISO 9635-2:2006), which has been
technically revised.
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 9635-2:2014(E)
Agricultural irrigation equipment — Irrigation valves —
Part 2:
Isolating valves
1 Scope
This part of ISO 9635 specifies construction and performance requirements and test methods for isolating
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 isolating irrigation valves of DN 8 in diameter or greater, designed to operate in
the fully open and fully closed positions, but which can also operate for extended time periods in any
intermediate position.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 9635-1:2014, Agricultural irrigation equipment — Irrigation valves — Part 1: General requirements
ISO 9644, Agricultural irrigation equipment — Pressure losses in irrigation valves — Test method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9635-1:2014 and the
following apply.
3.1
clear way valve
valve designed to have an unobstructed flow path which allows the passage of a theoretical sphere with
a diameter which is not less than the inside diameter of the body end port
[SOURCE: EN 736-3]
3.2
flow coefficient
K
V
proportionality factor equal to the flow rate, in cubic metres per hour, of water at a temperature between
5 °C to 50 °C, passing through the valve and causing a loss of static head of 1 bar
3
Note 1 to entry: QK= Δp , where Q is the flow rate in cubic metres per hour (m /h), and Δp is the pressure
V
2 2
drop across the valve, in bar or kilopond/kilogram-force per square centimetre (kp/cm , kgf/cm ).
2
Note 2 to entry: 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm .
Note 3 to entry: Adapted from EN 736-3.
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ISO 9635-2:2014(E)

3.3
full bore valve
valve with a seat diameter of not less than 90 % of the internal diameter of the body end port
[SOURCE: EN 736-3]
3.4
isolating valve
valve intended for use only in the fully closed or fully open position
[SOURCE: EN 736-1]
4 Design requirements
Isolating valves shall be designed in accordance with the requirements given in Clause 4 of
ISO 9635-1:2014.
5 Performance requirements
5.1 General
Perform all tests on the valve as it was delivered to the test facility.
5.2 Mechanical strength
5.2.1 Resistance to internal pressure of shell and all pressure-containing components
Carry out testing in accordance with ISO 9635-1:2014, 5.2.1. Test results shall comply with the
requirements of ISO 9635-1:2014, 5.2.1.
5.2.2 Resistance of obturator to differential pressure
Carry out testing in accordance with ISO 9635-1:2014, 5.2.2. Test results shall comply with the
requirements of ISO 9635-1:2014, 5.2.2.
Except for valves to be used for a single flow direction, perform the test successively in each flow direction.
5.2.3 Resistance of valve to bending
Carry out testing in accordance with ISO 9635-1:2014, 5.2.3, applying a bending moment, M, during the
test appropriate to the DN value of the valve in accordance with Table 1. Test results shall comply with
the requirements of ISO 9635-1:2014, 5.2.3.
Table 1 — Bending moments
Bending moment
DN M
N ⋅ m
8 610
10 615
20 640
25 670
NOTE For plastic-bodied valves, the applied bending
moment should be equal to the bending moment exerted by a
6 m long plastic tube of the same diameter (DN).
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ISO 9635-2:2014(E)

Table 1 (continued)
Bending moment
DN M
N ⋅ m
32 730
40 825
50 1 050
65 1 400
80 1 500
100 2 200
125 3 200
150 4 800
200 7 200
250 11 000
300 15 000
350 19 000
400 24 000
450 28 000
500 33 000
NOTE For plastic-bodied valves, the applied bending
moment should be equal to the bending moment exerted by a
6 m long plastic tube of the same diameter (DN).
5.2.4 Resistance of valves to operating loads
Test results shall comply with the requirements of ISO 9635-1:2014, 5.2.4.
In order to verify this requirement, test the valve in accordance with Annex A, with the application of
a closing torque and an opening torque equal to the minimum strength torque (mST), following which
it shall satisfy the requirements of the operating tests in accordance with 5.3.3, and the seat tightness
tests in accordance with 5.3.2.1 and 5.3.2.2.
The minimum strength torque shall be equal to twice the maximum operating torque given in 5.3.3. In
testing gate valves as specified in 5.3.3 c), apply a minimum strength torque (mST) as set out in Annex A
equal to 5 × the maximum operating torque (MOT). In the case of valves as specified in 5.3.3 d), the test
is applicable only when there is an additional manual operating element.
5.3 Watertightness and airtightness
5.3.1 Watertightness and airtightness of shell and all pressure-containing components
5.3.1.1 Internal pressure
Conduct testing in accordance with ISO 9635-1:2014, 5.3.1.1.
Test results shall comply with the requirements of ISO 9635-1:2014, 5.3.1.1.
5.3.1.2 External pressure
Conduct testing in accordance with ISO 9635-1:2014, 5.3.1.2.
Test results shall comply with the requirements of ISO 9635-1:2014, 5.3.1.2.
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ISO 9635-2:2014(E)

5.3.2 Seat tightness
5.3.2.1 Seat tightness at high differential pressure
Conduct testing in accordance with ISO 9635-1:2014, 5.3.2.1.
After closing the valve by application of the maximum operating torque (see 5.3.3), the leakage rate
shall not exceed rate A for resilient seated valves and shall not exceed rate B for metallic-seated valves.
Maintain the test pressure for 10 min.
Except for valves to be used in a single flow direction, perform the test successively in each flow direction.
5.3.2.2 Seat tightness at low differential pressure
Conduct testing in accordance with ISO 9635-1:2014, 5.3.2.2
After closing the valve by application of the maximum operating torque (see 5.3.3), the leakage rate
shall not exceed rate A for resilient seated valves and shall not exceed rate B for metallic seated valves.
Maintain the test pressure for 10 min.
Except for valves to be used in a single flow direction, perform the test successively in each flow direction.
5.3.3 Maximum operating torque (MOT) for operation and watertightness and airtightness
...