ISO 23551-1:2006
(Main)Safety and control devices for gas burners and gas-burning appliances — Particular requirements — Part 1: Automatic valves
Safety and control devices for gas burners and gas-burning appliances — Particular requirements — Part 1: Automatic valves
ISO 23551-1:2006 specifies safety, constructional and performance requirements and testing of automatic valves (hereafter referred to as valves) for gas burners, gas appliances and similar use. ISO 23551-1:2006 covers type testing only. ISO 23551-1:2006 applies to valves with declared maximum working pressures up to and including 500 kPa, for use on burners or in appliances using fuel gases as natural gas, manufactured gas or liquefied petroleum gas (LPG). ISO 23551-1:20061 applies to valves directly or indirectly operated electrically or by mechanical means. ISO 23551-1:2006 applies to valves actuated by fluids e.g. pneumatic, hydraulic. ISO 23551-1:2006 applies to valves where the flow rate is controlled by external electrical signals, either in discrete steps or proportional to the applied signal. ISO 23551-1:2006 applies to valves fitted with closed position indicator switches.
Dispositifs de commande et de sécurité pour brûleurs à gaz et appareils à gaz — Exigences particulières — Partie 1: Robinets automatiques
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 23551-1
First edition
2006-07-01
Safety and control devices for gas
burners and gas-burning appliances —
Particular requirements —
Part 1:
Automatic valves
Dispositifs de commande et de sécurité pour brûleurs à gaz et appareils
à gaz — Exigences particulières —
Partie 1: Robinets automatiques
Reference number
ISO 23551-1:2006(E)
©
ISO 2006
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ISO 23551-1:2006(E)
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ii © ISO 2006 – All rights reserved
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ISO 23551-1:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Classification. 3
4.1 Classes of control. 3
4.2 Groups of controls. 4
5 Test conditions . 4
6 Construction. 4
6.1 General. 4
6.2 Construction requirements. 4
6.3 Materials . 5
6.4 Gas connections. 6
6.5 Electrical material . 7
7 Performance . 8
7.1 General. 8
7.2 Leak-tightness. 8
7.3 Torsion and bending . 8
7.4 Rated flow rate . 8
7.5 Durability . 9
7.6 Functional requirements. 9
7.7 Endurance . 13
8 EMC/Electrical requirements. 15
8.1 Protection against environmental influences. 15
8.2 Variations in supply voltage . 15
8.3 Short-term voltage interruptions and drops . 15
8.4 Variations in supply frequency . 15
8.5 Surge immunity test . 15
8.6 Electrical fast transient/burst . 15
8.7 Immunity to conducted disturbances. 15
8.8 Immunity to radiated fields . 15
8.9 Electrostatic discharge immunity test. 15
8.10 Test for immunity to power-frequency magnetic field. 15
8.11 Electrical requirements . 15
9 Marking, installation and operating instructions . 16
9.1 Marking . 16
9.2 Installation and operating instructions . 16
9.3 Warning notice . 17
Bibliography . 18
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ISO 23551-1:2006(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 23551-1 was prepared by Technical Committee ISO/TC 161, Control and protective devices for gas and
oil burners and gas and oil burning appliances.
ISO 23551 consists of the following parts, under the general title Safety and control devices for gas burners
and gas-burning appliances — Particular requirements:
⎯ Part 1: Automatic valves
⎯ Part 2: Pressure regulators
⎯ Part 3: Gas/air ratio controls, pneumatic type
⎯ Part 4: Valve-proving systems for automatic shut-off valves
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ISO 23551-1:2006(E)
Introduction
This part of ISO 23551 is designed to be used in conjunction with ISO 23550:2004.
This part of ISO 23551 either references existing requirements of ISO 23550:2004 or indicates that there has
been an “addition”, “modification” or “replacement” in the cited requirement of ISO 23550:2004.
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INTERNATIONAL STANDARD ISO 23551-1:2006(E)
Safety and control devices for gas burners and gas-burning
appliances — Particular requirements —
Part 1:
Automatic valves
1 Scope
This part of ISO 23551 specifies safety, constructional and performance requirements and testing of automatic
valves (hereafter referred to as valves) for gas burners, gas appliances and similar use.
This part of ISO 23551 covers type testing only.
This part of ISO 23551 applies to valves with declared maximum working pressures up to and including
500 kPa, for use on burners or in appliances using fuel gases as natural gas, manufactured gas or liquefied
petroleum gas (LPG).
This part of ISO 23551 applies to valves directly or indirectly operated electrically or by mechanical means.
This part of ISO 23551 applies to valves actuated by fluids e.g. pneumatic, hydraulic.
This part of ISO 23551 applies to valves where the flow rate is controlled by external electrical signals, either
in discrete steps or proportional to the applied signal.
This part of ISO 23551 applies to valves fitted with closed position indicator switches.
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 4400, Fluid power systems and components — Three-pin electrical plug connectors with earth contact —
Characteristics and requirements
ISO 6952, Fluid power systems and components — Two-pin electrical plug connector with earth contact —
Characteristics and requirements
ISO 23550:2004, Safety and control devices for gas burners and gas-burning appliances — General
requirements
IEC 60529, Degrees of protection provided by enclosures
IEC 60730-1, Automatic electrical controls for household and similar use — Part 1: General requirements
IEC 61058-1:2001, Switches for appliances — Part 1: General requirements
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ISO 23551-1:2006(E)
3 Terms and definitions
For the purpose of this document, the terms and definitions given in ISO 23550:2004 and the following apply.
3.1
automatic valve
device consisting essentially of a valve body, closure member, and actuator that controls the flow of gas
NOTE 1 The actuator can be actuated by electrical or mechanical means.
NOTE 2 The actuation can be done by gas pressure or electrical, hydraulic or pneumatic energy.
3.2
automatic shut-off valve
valve which opens when energized and closes automatically when de-energized
3.3
valve with step control
valve which controls the flow rate in steps
3.4
valve with modulating control
valve which controls the flow rate continuously between two limits in response to external signals
3.5
actuating mechanism
part of the valve which moves the closure member
3.6
closed position indicator switch
switch fitted to a valve which indicates when the closure member is in the closed position
3.7
actuating energy
required energy for the actuating mechanism to move the closure member to the open position
NOTE The actuating energy can have an external source (electrical, pneumatic or hydraulic) and can be transformed
inside the valve.
3.8
closing force
force available to close the valve, independent of any force provided by fuel gas pressure
3.9
sealing force
force acting on the valve seat when the closure member is in the closed position, independent of any force
provided by fuel gas pressure
3.10
frictional force
largest force required to move the actuating mechanism and the closure member from the open position to the
closed position with the closure spring removed, independent of any force provided by fuel gas pressure
3.11
actuating pressure
hydraulic or pneumatic pressure supplied to the actuating mechanism of the valve
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ISO 23551-1:2006(E)
3.12
pressure difference
difference between the inlet and outlet pressures
3.13
opening time
time interval between energizing the valve and the attainment of the maximum or other defined flow rate
3.14
closing time
time interval between de-energizing the valve and the closure member attaining the closed position
3.15
delay time
time interval between energizing the valve and the start of flow
3.16
control valve
valve which controls the fluid (e.g. compressed air) supplied to the actuating mechanism
3.17
rated voltage
voltage declared by the manufacturer at which the valve may be operated
3.18
rated current
current declared by the manufacturer at which the valve may be operated
3.19
bypass
passage, provided in the body of the device or in a gas line around the body, which permits a gas flow from
the inlet to the outlet connections of the device entirely independent of the action of the valve
4 Classification
4.1 Classes of control
If valves are classified, the following classes shall be used:
⎯ Classes A, B and C: valves where the sealing force is not decreased by the gas inlet pressure. They
are classified A, B or C according to the sealing force requirements of 7.6.10;
⎯ Class D: valves that are not subject to any sealing force requirements;
⎯ Class E: valves where the sealing force is decreased by the gas inlet pressure and that
meet the requirements of 7.6.10;
⎯ Class J: disc-on-seat valves, where the sealing force is not decreased by the gas inlet
pressure and that meet the requirements of 7.6.10.
NOTE In USA, Canada and Japan, valves are not classified.
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ISO 23551-1:2006(E)
4.2 Groups of controls
A valve is classified as group 1 or group 2 according to the bending stresses that it is required to withstand
(see ISO 23550:2004, Table 4):
⎯ Group 1: valves for use in an appliance and/or installation where they are not subjected to bending
stresses imposed by installation pipe work (e. g. by the use of rigid adjacent supports);
⎯ Group 2: valves for use in any situation, either internal or external to the appliance, typically without
support.
NOTE A valve that meets the requirements of group 2 valves also meets the requirements of group 1 valves.
5 Test conditions
ISO 23550:2004, Clause 5, shall apply.
6 Construction
6.1 General
ISO 23550:2004, 6.1, shall apply.
6.2 Construction requirements
6.2.1 Appearance
ISO 23550:2004, 6.2.1, shall apply.
6.2.2 Holes
ISO 23550:2004, 6.2.2, shall apply.
6.2.3 Breather holes
ISO 23550:2004, 6.2.3, shall apply.
6.2.4 Screwed fastenings
ISO 23550:2004, 6.2.4, shall apply.
6.2.5 Jointing
ISO 23550:2004, 6.2.5, shall apply.
6.2.6 Moving parts
ISO 23550:2004, 6.2.6, shall apply.
6.2.7 Sealing caps
ISO 23550:2004, 6.2.7, shall apply.
6.2.8 Dismantling and reassembling for servicing and/or adjustment
ISO 23550:2004, 6.2.8, shall apply.
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ISO 23551-1:2006(E)
6.2.9 Auxiliary channels
ISO 23550:2004, 6.2.9, shall apply.
6.2.10 Closed position indicator switch
Closed position indicator switches, where fitted, shall not impair the correct operation of valves. Adjusters shall
be sealed to indicate interference. Any drift of the switch and actuating mechanism from its setting shall not
impair correct valve operation.
6.2.11 Flow rates
Flow rates of valves with modulating control shall be adjustable over the full range declared by the
manufacturer. If the adjustment of one flow rate affects the setting of any other flow rate, this shall be clearly
indicated in the manufacturer's instructions for setting up. The setting of any flow rate shall require the use of
tools and shall be sealed to discourage unauthorized adjustment.
6.2.12 Protection of the valve mechanism
The mechanisms of automatic valves shall be protected by substantial enclosures so as to prevent
interference with the safe operation of the devices.
6.2.13 By-pass
Valves classified as classes A, B, C, D, E and J shall not incorporate a by-pass.
6.3 Materials
6.3.1 General material requirements
ISO 23550:2004, 6.3.1, shall apply.
6.3.2 Housing
6.3.2.1 Housing design
ISO 23550:2004, 6.3.2.1, shall apply with the following addition.
When a diaphragm inside a housing separates the gas-carrying compartment from atmosphere, then the gas-
carrying compartment is considered to be indirectly separated.
6.3.2.2 Test for leakage of housing after removal of non-metallic parts
Carry out the test as given in ISO 23550:2004; 6.3.2.2.
6.3.3 Springs
6.3.3.1 Closure springs
ISO 23550:2004, 6.3.3.1 shall apply.
6.3.3.2 Springs providing closing force and sealing force
ISO 23550:2004, 6.3.3.2, shall apply.
NOTE This is applicable when closing force and sealing force is provided by spring action.
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ISO 23551-1:2006(E)
6.3.4 Resistance to corrosion and surface protection
ISO 23550:2004, 6.3.4, shall apply.
6.3.5 Impregnation
ISO 23550:2004, 6.3.5, shall apply.
6.3.6 Seals for glands for moving parts
ISO 23550:2004, 6.3.6, shall apply.
6.3.7 Closure members
Closure members of valves above DN 25 shall either have a mechanical support (e. g. metallic) to withstand
the sealing force or shall be made of metal.
This requirements also applies to
⎯ all valves with a maximum working pressure above 15 kPa;
⎯ parts transmitting the closing force.
6.4 Gas connections
6.4.1 Making connections
ISO 23550:2004, 6.4.1, shall apply.
6.4.2 Connection sizes
ISO 23550:2004, 6.4.2, shall apply.
6.4.3 Threads
ISO 23550:2004, 6.4.3, shall apply.
6.4.4 Union joints
ISO 23550:2004, 6.4.4, shall apply.
6.4.5 Flanges
ISO 23550:2004, 6.4.5, shall apply.
6.4.6 Compression fittings
ISO 23550:2004, 6.4.6, shall apply.
6.4.7 Nipples for pressure tests
ISO 23550:2004, 6.4.7, shall apply.
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ISO 23551-1:2006(E)
6.4.8 Strainers
ISO 23550:2004, 6.4.8, shall apply with the following two additions.
Class J valves shall incorporate an inlet strainer. The maximum strainer hole dimension shall not exceed
0,28 mm and it shall prevent the passage of a 0,2 mm diameter pin gauge.
Strainers fitted to valves of DN 25 and above shall be accessible for cleaning or replacement without removing
the valve body pipe connections from the pipe work.
6.4.9 Pneumatic and hydraulic actuating mechanisms
Pneumatically or hydraulically actuated valves shall be provided with protection to ensure that the blockage of
an orifice in the control system does not adversely affect the ability of the valve to close.
6.5 Electrical material
6.5.1 Degree of protection
The degree of protection shall be declared by the manufacturer in accordance with IEC 60529.
In USA and Canada the degree of protection is declared in accordance with NEMA 250 or UL 50.
6.5.2 Switches
Switches shall conform to IEC 610
...
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