ISO 9635-1:2006

INTERNATIONAL ISO
STANDARD 9635-1
First edition
2006-11-15
Agricultural irrigation equipment —
Irrigation valves —
Part 1:
General requirements
Matériel agricole d'irrigation — Vannes d'irrigation —
Partie 1: Exigences générales
Reference number
©
ISO 2006
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©  ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Design requirements . 4
4.1 Materials . 4
4.2 DN. 4
4.3 Pressures. 4
4.4 Temperatures . 4
4.5 Design of shell and obturator. 5
4.6 End types and interchangeability . 5
4.7 Operating direction. 5
4.8 Maximum water velocity . 5
4.9 Valve parts. 5
4.10 Internal corrosion and ageing resistance . 6
4.11 External corrosion and ageing resistance . 6
4.12 Repairs and maintenance . 6
5 Performance requirements . 6
5.1 Mechanical strength . 6
5.2 Watertightness . 7
5.3 Hydraulic characteristics . 8
5.4 Resistance to chemicals and fertilizers. 8
5.5 Endurance test . 8
6 Conformity assessment . 8
6.1 General. 8
6.2 Type tests . 8
6.3 Control of production process and quality system . 9
7 Marking . 9
8 Packaging . 9
Annex A (normative) Test method for resistance to internal pressure of shell and all
pressure-containing components. 10
Annex B (normative) Test method for resistance of obturator to differential pressure . 11
Annex C (normative) Test method for resistance of valves to bending. 13
Annex D (normative) Minimal test method for watertightness to external pressure of shell and all
pressure-containing components. 15
Annex E (normative) Test method for resistance to chemicals and fertilizers. 16
Annex F (normative) Test method for water or air tightness of valve body . 17
Annex G (normative) Test method for seat tightness . 19
Bibliography . 24

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 9635-1 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 9635-1, together with ISO 9635-2, ISO 9635-3, ISO 9635-4 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
iv © ISO 2006 – All rights reserved

INTERNATIONAL STANDARD ISO 9635-1:2006(E)

Agricultural irrigation equipment — Irrigation valves —
Part 1:
General requirements
1 Scope
This part of ISO 9635 specifies construction and performance requirements and test methods for 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 irrigation valves of 15 mm 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 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 4633, Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for
materials
ISO 5209, General purpose industrial valves — Marking
ISO 5752, Metal valves for use in flanged pipe systems — Face-to-face and centre-to-face dimensions
ISO 6708:1995, Pipework components — Definition and selection of DN (nominal size)
ISO 7005-1, Metallic flanges — Part 1: Steel flanges
ISO 7005-2, Metallic flanges — Part 2: Cast iron flanges
ISO 7005-3, Metallic flanges — Part 3: Copper alloy and composite flanges
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 9635-2:2006, Agricultural irrigation equipment — Irrigation valves — Part 2: Isolating valves
ISO 9635-3:2006, Agricultural irrigation equipment — Irrigation valves — Part 3: Check valves
ISO 9635-4:2006, Agricultural irrigation equipment — Irrigation valves — Part 4: Air valves
ISO 9635-5:2006, Agricultural irrigation equipment — Irrigation valves — Part 5: Control valves
ISO 9644, Agricultural irrigation equipment — Pressure losses in irrigation valves — Test method
1)
ISO 9911:— , Agricultural irrigation equipment — Manually operated small plastics valves
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
EN 681-1, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 1: Vulcanized rubber
EN 12627, Industrial valves — Butt welding ends for steel valves
EN 12982, Industrial valves — End-to-end and centre-to-end dimensions for butt welding end valves
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
maximum operating torque
maximum limit of torque which, when applied at the shaft, operates the valve and ensures compliance with the
required leakage rate
3.2
minimum strength torque
minimum limit of torque which, when applied at the shaft with the obturator either totally open or totally closed,
causes no alteration to the functional capability of the valve
3.3
shaft
point where the load (torque) is applied in order to change the position of the valve obturator, which may be
the end of the stem, or the input shaft of the reducer when the reducer is an integral part of the valve
3.4
type test
test made to prove that the design meets the corresponding performance requirements in this part of
ISO 9635 and the part of ISO 9635 related to the specific valve being tested
3.5
operating mechanism
mechanism which translates the motion of the operating device to the motion of the obturator
[EN 736-2]
3.6
operating device
manual or power operated device used to operate the bare valve
[EN 736-2]
3.7
operating element
component of the operating device by which the mechanical power is introduced
[EN 736-2]
1) To be published. (Revision of ISO 9911:1993)
2 © ISO 2006 – All rights reserved

3.8
DN
alphanumeric designation of the size of pipe work components, used for reference purposes, comprising the
letters DN followed by a dimensionless round number which is loosely related to the effective dimensions, in
millimetres, of the bore or external diameter of the end connections
NOTE Adapted from ISO 6708:1995, definition 2.1.
3.9
nominal pressure
PN
numerical designation which is a convenient rounded number for reference purposes, designated by the
letters PN followed by a dimensionless round number which is loosely related to the pressure, expressed in
bars
5 2
NOTE 1 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
NOTE 2 Adapted from ISO 7268:1983/Amd 1:1984.
3.10
allowable operating pressure
PFA
maximum hydrostatic pressure that a component is capable of withstanding continuously in service
3.11
maximum allowable pressure
PMA
maximum pressure occurring from time to time, including surge, that a component is capable of withstanding
in service
3.12
allowable site test pressure
PEA
maximum hydrostatic pressure that a newly installed component is capable of withstanding for a relatively
short duration, in order to ensure integrity and tightness of the pipeline
3.13
obturator
movable component of the valve whose position in the fluid flow path restricts or obstructs the fluid flow
4 Design requirements
4.1 Materials
4.1.1 Components and coating materials
Components and coating materials shall be selected from those conforming to the relevant standards, where
existent. They shall also be in accordance with 4.9, 4.10 and 4.11, either alone or in combination with coating
materials.
4.1.2 Elastomers
Elastomers shall be in accordance with ISO 4633 or EN 681-1 and 4.10 of this part of ISO 9635.
4.2 DN
The DN values shall be selected from the preferred values given in ISO 6708, with an upper limit of DN 2 000.
The manufacturer shall indicate whether a DN value is from the DN/ID series or from the DN/OD series.
4.3 Pressures
Valves intended for irrigation systems come under the nominal pressure (PN) designation and shall be
designed in such a way that their characteristic pressures, allowable operating pressure (PFA), maximum
allowable pressure (PMA) and allowable site test pressure (PEA) are in accordance with Table 1 for the
corresponding PN (see also 4.4).
Table 1 — Valve pressures
Pressure
bar
PN
a a b
PFA PMA PEA
6 6 8 12
10 10 12 17
16 16 20 25
25 25 30 35
a
Applicable to valves in all positions, from fully closed to fully open.

b
Applicable only to valves not in the closed position.

Table 1 gives minimum values of PMA and PEA. The manufacturer’s catalogue can indicate higher values on
the condition that the requirements of this part of ISO 9635 have been verified with these higher values. In this
case, PEA shall not be less than the lesser of 1,5 PMA or (PMA + 5) bar.
4.4 Temperatures
Valves shall be designed for service temperatures from 1 °C to 60 °C and for storage temperatures between
−40 °C and 70 °C. For valves made from materials with temperature-dependent mechanical behaviour, the
PFA, PMA and PEA shall be established at (23 ± 3) °C and, if applicable, a factor (temperature/pressure
table) for higher temperatures shall be given by the product standards and/or the manufacturer.
4 © ISO 2006 – All rights reserved

4.5 Design of shell and obturator
Valves shall be designed to ensure a safety factor against short-term and long-term shell and obturator
rupture, taking account of PFA, PMA and PEA according to 4.3. This requirement shall not preclude any of the
performance requirements given in Clause 5.
The design shall be carried out using either one or the other of the following methods.
⎯ A calculation method using the tensile strength of the material (as defined in the relevant material
standards) divided by a safety factor: for materials with time-dependent mechanical behaviour (such
as plastic materials), the tensile strength shall be the 20 °C fifty-year extrapolated minimum strength
obtained from pressure tests on injection moulded or extruded pipes subjected to constant
hydrostatic pressure at various temperatures and for different lengths of time in accordance with
ISO 9080.
⎯ An experimental method, by means of pressure tests on valve shells subjected to a constant
hydrostatic pressure equal to PMA times a safety factor: for materials with time-dependent
mechanical behaviour (such as plastic materials), the test pressure shall be further multiplied by a
coefficient specific to each material in order to take account of its fifty-year extrapolated minimum
strength and of the slope of its strength regression line.
4.6 End types and interchangeability
Valves can be designed with various types of end connections adapted to specific pipe systems. The
connections shall fulfil the standardized requirements of the relevant pipe systems.
In order to ensure interchangeability of flanged valves, their face-to-face or centre-to-face dimensions shall be
in accordance with ISO 5752 and their flanges with ISO 7005-1, ISO 7005-2 or ISO 7005-3 (depending on the
flange material). In the case of steel valves with welded ends, the end-to-end and centre-to-end dimensions
shall be in accordance with EN 12982 or EN 12627.
4.7 Operating direction
For valves with an operating mechanism, the preferred direction of closure is clockwise.
Valves, designed for anti-clockwise closure, shall be marked to indicate the closing direction.
4.8 Maximum water velocity
Valves shall be designed for water flow velocities that can reach the values given in Table 2 in steady flow
conditions.
Table 2 — Maximum water flow velocity
PFA Flow velocity
bar m/s
6 2,5
10 3
16 4
25 5
4.9 Valve parts
Valve parts that are in contact with water shall be of non-toxic materials. All parts belonging to valves of the
same size, type and model, and produced by the same manufacturer, shall be interchangeable.
4.9.1 Plastic valves
Plastic valves shall be in accordance with ISO 9911.
Plastics parts of the valve that are exposed to ultraviolet (UV) radiation under normal field conditions in
which the valve operates shall include additives to improve their resistance to UV radiation. Plastics parts
that enclose waterways shall be opaque or shall be provided with an opaque cover designed to block all
light from reaching clear waterway enclosures.
4.10 Internal corrosion and ageing resistance
Valve parts that are in contact with water shall be resistant to, or protected against, corrosion under the
working conditions for which the valve is intended. The valve body shall meet the salt spray test
requirements in accordance with ISO 9227.
4.11 External corrosion and ageing resistance
Under the usage conditions defined in this part of ISO 9635, all external surfaces of the valve (including bolts)
which are in continuous contact with the surrounding soil, water or atmosphere shall be resistant to corrosion
and ageing by the selection of materials, or shall be protected by appropriate means. The valve body shall
meet the salt spray test requirements in accordance with ISO 9227.
4.12 Repairs and maintenance
The valve shall be designed to permit internal repair and maintenance without removing the valve body from
the line.
5 Performance requirements
All tests shall be performed at a water temperature of (23 ± 3) °C, unless otherwise specified. All tests are to
be performed on the valve as it was delivered to the test facility.
5.1 Mechanical strength
5.1.1 Resistance of shell and all pressure-containing components to internal pressure
The valves shall withstand, without visible damage, an internal pressure equal to the higher of the two values:
PEA or 1,5 × PFA.
In order to verify this requirement, the valve, as delivered, shall be tested in accordance with the test method
given in Annex A, following which there shall be no visually detectable external leakage and no other sign of
defect.
5.1.2 Resistance of obturator to differential pressure
The valves in the closed position shall withstand, without visible damage, a differential pressure applied to the
obturator equal to the lower of the two values: 1,5 × PFA or PFA + 5. If the PMA indicated for the valves is
higher than this value, the differential pressure applied shall be equal to PMA.
In order to verify this requirement, the valve shall be tested according to the test method given in Annex B,
following which it shall pass the seat tightness test according to 5.2.2.
5.1.3 Resistance of valves to bending
Valves which are designed to be rigidly connected at both ends to adjacent pipes, excluding wafer type
valves, shall withstand the stresses transmitted to them without sustaining any deformation likely to alter their
functional capabilities beyond the limits specified in Annex C.
6 © ISO 2006 – All rights reserved

In order to verify this requirement, the valve shall be tested using the test method and with a bending moment
M in accordance with Annex C at a differential pressure across the obturator equal to PFA ± 5 %. It shall,
under the bending test load:
⎯ show no visually detectable external leakage;
⎯ exhibit a leakage rate at the obturator (see 5.2.2) not higher than that immediately above the seat leakage
rate specified for new valves (e.g. rate B if the specified rate is rate A according to Annex G).
5.1.4 Resistance of valves to operating loads
Valves having a mechanically operated obturator shall withstand, in the fully open and in the fully closed
positions, the minimum strength torque (mST) without any damage likely to impair their functional capabilities
beyond the limits specified in Annex B.
The test method, the mST to be applied and the acceptance criteria shall be in accordance with Annex C.
5.2 Watertightness
5.2.1 Watertightness of shell and all pressure-containing components
5.2.1.1 Internal pressure
The valves shall be leak-tight under an internal water pressure equal to the higher of the two values: PEA or
1,5 × PFA.
In order to verify this requirement, the valve shall be subjected to a water pressure test in accordance with
5.1.1, or to an air pressure test at (6 ± 1) bar in accordance with Annex F, following which there shall be no
visually detectable leakage.
NOTE Air testing is applicable only when pressure vessel regulations permit.
5.2.1.2 External pressure
Valves shall be watertight to ingress of air, water or any foreign matter.
In order to verify this requirement, the valve shall be tested in accordance with the method given in Annex D.
Any variation of pressure during the test shall not exceed 0,02 bar.
5.2.2 Seat tightness
5.2.2.1 Seat tightness at high differential pressure
The seat of valves in the fully closed position shall be watertight within a defined leakage rate, selected from
rate A to rate F according to Annex G. The allowed leakage rate shall be given in the manufacturer’s technical
data.
In order to verify this requirement, the valve as delivered shall be subjected to the test in accordance with
Annex G under a differential pressure equal to 1,1 × PFA for water, or (6 ± 1) bar for air. The measured
leakage rate shall not exceed the allowed leakage rate.
5.2.2.2 Seat tightness at low differential pressure
The requirement shall be in accordance with 5.2.2.1.
The test shall be carried out in accordance with 5.2.2.1, but under a differential water pressure of 0,5 bar.
5.3 Hydraulic characteristics
5.3.1 Pressure loss
Carry out this test in accordance with ISO 9644. The pressure loss measured at a particular flow rate shall
not exceed the pressure loss declared by the manufacturer at that same flow rate by more than +5 %.
5.3.2 Other
Other hydraulic characteristics of control valves shall
...