1 Scope This European Standard defines the constructional and operational characteristics, the safety requirements and test methods, and the marking of automatic change over devices with
General terms and definitions
Automatic changeover devices ensure continuous gas supply by automatically switching to a reserve cylinder or series of cylinders when the pressure from a preselected service cylinder drops below a specified threshold These devices regulate upstream gas pressure within defined limits to maintain a consistent regulated pressure Additionally, they feature a supply-reserve indicator that helps identify which cylinder or series of cylinders is currently in use.
The terminology used is shown in Figure 1 The diagram is shown as a guide, no other method is excluded
3.1.2 automatic change over devices system system of several regulators designed and adjusted in such a way as to operate like an automatic change over device as in 3.1.1 (see annex B)
Figure 1 — Diagram of an automatic change over devices
3.1.3 fixed automatic change over device automatic change over device whose regulated pressure is adjusted by the manufacturer and fixed and whose adjustment cannot be modified by the user
3.1.4 variable automatic change over device automatic change over device whose regulated pressure may be modified by the user simple manipulation between two fixed limits
3.1.5 adjustable automatic change over device automatic change over device whose regulated pressure may only be modified by a specialist at the time of installation; it is then fixed fashion
3.1.6 tap device for closing the gas flow which requires an intentional manual action (for example on a lever, a knob, etc )
The valve is a crucial component of the regulation subassembly, ensuring a secure connection between the automatic changeover devices at supply pressure and those at regulated pressure, particularly when this pressure matches the lock-up pressure.
Sealing any device arrangement, such as an adjuster, ensures that any interference likely to alter its setting results in the breaking of the device or sealing material, thereby making the interference noticeable.
The nominal diameter (DN) is a numerical designation that applies to all components within a piping system, excluding those identified by their external diameter or thread size This whole number serves as a reference and is approximately related to the manufacturing dimensions of the components.
Terms and definitions concerning gas
Butane is a member of the third family of gases, characterized by a vapor pressure (p v) ranging from 4.3 bar to 7.5 bar at 50 °C, and it has an average volumetric mass in the gas phase of 2.4 kg/m³.
Propane is a third family gas mixture characterized by a vapor pressure (p v) ranging from 7.5 bar to 16 bar at 50 °C, with an average volumetric mass in the gas phase of 1.85 kg/m³.
LPG is a mixture of third family gases characterized by a vapor pressure of at least 4.3 bar and up to 16 bar at 50 °C, with an average volumetric mass in the gas phase of 2.12 kg/m³.
Terms and definitions concerning pressures
Values of pressures given in the text are to be considered as values of relative pressure and are expressed in bar (bar) or millibar (mbar)
3.3.1 supply pressure p value of the gas pressure measured at the automatic change over device’s inlet
3.3.2 regulated pressure value of the gas pressure measured at the automatic change over device outlet or of the automatic change over device system as described in annex B
3.3.3 nominal regulated pressure p d value of the regulated pressure corresponding:
⎯ either to the normal pressure for appliances as defined in 3.6 of EN 437:2003;
⎯ or to the normal pressure for appliances operating outside the scope of EN 437;
⎯ or to an intermediate pressure allowing the supply of a second stage regulator under the conditions of 6.2
From this pressure the operational limits of the automatic change over devices are obtained This pressure is marked on the automatic change over devices
!lock up pressure" p 0 maximum regulated pressure obtained at no rate and for which all the values of the supply pressure between the limits given in 6.1
The minimal admitted pressure, denoted as \( p_{Mg} \), represents the lowest regulated pressure provided by the automatic changeover device, applicable across all supply pressure levels and flow rates.
The maximal admitted pressure, denoted as \( p_{Mp} \), represents the highest regulated pressure that the automatic changeover device can deliver across all supply pressure levels and flow rates within the operational range.
The nominal pressure value, denoted as \( p \), is adjusted in the change over function of two-stage automatic change over devices, which incorporate both a change over function and a regulator.
Terms and definitions concerning rates
M g mass flow of gas that can be obtained, for any value of the supply pressure, at the "working" and "reserve" pressures between the specified limits
NOTE The guaranteed rate is expressed in grams per hour (g/h)
The M p automatic changeover device is designed for gas flow rates up to 4 kg/h and operates under pressures that meet EN 437 standards It features a pilot rate of 15 g/h, which is essential for supplying the ignition system of the appliance, commonly referred to as the pilot.
NOTE The pilot rate is expressed in grams per hour (g/h)
3.4.3 closing area for automatic change over device over than 4 kg/h or for pressures not complying with EN 437 the closing area is the range between 0 % and 5 % of the guaranteed rate
3.4.4 operational area rate range between the pilot rate or the maximum of the closing area and 100 % of the guaranteed rate
4 Types of automatic change over devices
Introduction
There are typically two types of automatic change over device with pressure reduction:
Single stage automatic change over devices
• the supply pressure of the automatic change over device is equal to the pressure of the LPG supply containers;
• the automatic change over device supplies a gas appliance
First stage automatic Regulator change over device
• the supply pressure of the automatic change over devices is equal to the pressure of the LPG supply containers;
• the supply pressure of the regulator depends on the regulated pressure of the automatic change over device and on the pressure losses in the intermediate line;
• this regulator, covered by !EN 13785", supplies a gas appliance or another regulator.
Automatic change over devices for installations where the final regulator supplies a pressure
Where an automatic change over device is a single stage it shall be fixed
It is recommended that a first stage automatic change over device is fixed
For interchangeability the recommended nominal values of regulated pressures (p d ) of the first stage automatic change over device are the following:
Other automatic change over devices installation
To supply appliances with pressures which are different from those specified by EN 437 fixed, variable or adjustable automatic change over devices are used
General
Automatic change over devices shall be designed, manufactured and assembled in such a way that their operation is satisfactory under the installation and service conditions specified by the manufacturer
Safety devices installed on automatic changeover devices must be designed and constructed according to the specifications outlined in Annex A of this standard.
All the parts of an automatic change over devices shall be free of sharp corners or edges capable of causing deterioration, injury or faulty operation
Parts shall be clean internally and externally
Screw and pin holes for assembling and securing automatic changeover device components must not intersect with gas pathways Additionally, there should be a minimum wall thickness of 1 mm between these holes and the gas pathways.
Holes required for machining that connect gas pathways to the atmosphere, without affecting the function of automatic changeover devices, must be permanently sealed with metal Additional sealing compounds can be utilized as needed.
Gas tight threads shall be in accordance with ISO 7-1, where pressure-tight joints are made on the threads or with ENPT
Devices that can alter the function of the automatic changeover device must remain properly adjusted and sealed Specifically, the assembly of the device's body and cover should be designed to prevent separation without causing permanent damage to either component or the seal.
Materials
The materials' quality, dimensions, and assembly methods must ensure secure construction and performance The performance characteristics should remain stable throughout the expected lifespan when the automatic changeover device is installed and operated according to the manufacturer's guidelines Under normal conditions, all components must endure the mechanical, chemical, and thermal stresses they encounter during use.
The automatic change over devices shall withstand the action of organic substances, either of vegetable or animal origin
The body shall be made of metallic material
Internal components and cover parts not associated with pressure, excluding connections (refer to Figure 1), can be constructed from non-metallic materials such as thermoplastics or thermosetting substances, as long as specific requirements are satisfied.
⎯ materials used shall meet the requirements of annex E;
⎯ whole automatic change over devices shall withstand the various tests described in the body of the standard;
⎯ automatic change over device with its non metallic parts removed shall resist a pressure test as in 7.2.1.3 remaining sound in the sense of 5.5 and without causing any danger
Zinc alloys must meet the Zn Al4 or Zn Al4 Cu1 quality standards as per ISO 301 and should not be subjected to temperatures exceeding 80 °C, similar to non-metallic components Additionally, brass alloys are required to conform to EN 12164 or EN 12165 standards.
Rotating threaded connections, both male and female, must be constructed from brass in compliance with EN 12164 or EN 12165 standards, or alternatively from steel It is essential that the materials and manufacturing processes employed do not introduce any risk of stress corrosion.
Steel internal parts shall be protected against corrosion
Threaded fixed connection parts must be constructed from metallic materials, while non-threaded fixed connection parts can be made from non-metallic materials, as long as they meet the testing requirements outlined in Annex E.
The assembly of parts of the gas ways intended to assure soundness shall not be made with solder whose lowest temperature in the melting range, after application, is below 450 °C
Non metallic (thermoplastic or thermal setting) components used in the construction of an automatic change over device shall meet the special requirements of annex E
Elastomeric components must meet the standards outlined in EN 549, particularly regarding temperature specifications and ozone resistance for diaphragms Furthermore, reinforced materials are required to adhere to the additional criteria specified in annex F.
Special requirements
Pressure sensing subassembly
The dimensions, the shape and the method of assembly of the components of the pressure sensing subassembly shall avoid any risk of damaging the diaphragm
The pressure sensing subassembly must be designed to ensure that the automatic changeover device operates according to the specifications outlined in clause 6, regardless of its installation position as directed by the manufacturer Additionally, the device must fulfill the "lock up pressure" requirements in all designated mounting orientations.
Whatever the position taken by the diaphragm, the spring shall not be fully compressed
The diaphragm shall withstand, without rupture or slipping out of its fixing, the tests described in 7.2.1.2.
Regulation subassembly
At the lockout position, the regulation subassembly shall act as a seal between the supply pressure and the regulated pressure It shall not move accidentally in use
The soundness and function of the regulation subassembly shall not be affected by the tensile strength and bending tests on the connections
After the test defined in 7.2.3, the valve, as defined in !3.1.7", shall not be displaced or come out of its housing.
Back pressure subassembly
The design of the support surfaces for both the cover and the body must ensure that the diaphragm is securely held in place, enabling it to withstand the pressure tests specified in section 7.2.1.
To minimize the risks of accidental blockage and prevent rainwater penetration, it is essential to mount or position items appropriately, especially when their cross-sectional area exceeds 3 mm².
The design of the device ensures protection against accidental damage to its internal components from any objects that may enter through the vent, provided that the automatic changeover device is installed according to the specified instructions.
Adjustable automatic changeover devices must allow for the adjustment of settings during installation, after which the settings should be lockable and the device sealable to ensure security and prevent tampering.
Connection subassembly
Automatic changeover devices must include an inlet filter made from corrosion and gas-resistant materials, positioned upstream of the valve pad The filter mesh should comply with ISO 565 standards for a 125 opening and must not exceed a diameter of 0.14 mm if using perforated sheet.
If the filter is not integral with the automatic change over device the instructions shall state the location of separate filter upstream."
The connections shall be of the following types:
⎯ flanged: when flanges are used, they shall fit connections in accordance with ISO 7005-2 with dimensions corresponding to PN 16;
Threaded inlet connections, where the seal is formed on the thread, are suitable for use with a nominal diameter of up to DN 50 Additionally, parallel internal connection threads made of zinc or aluminum are allowed for sizes up to and including this diameter.
The equivalences of the dimensions of connections are given in Table 1
Thread as in ISO 7-1 or in EN ISO 228-1
Nominal size of flanges as in ISO 7005-2
The connections shall comply with: a) inlet connections:
1) one of the types in Figures G.1 to G.49 1) if they are threaded;
2) one of the types in Figures G.50 to G.99 2) if they are not threaded;
3) future types will be acceptable providing they are not interchangeable with the connections specified in this European Standard, and providing their assembly gives an equivalent degree of safety;
4) for connections made with a rotating nut using a seal the backward movement of the nut shall be sufficient to expose the seal completely b) outlet connections:
1) one of the types in Figures H.1 to H.49 3) if they are threaded;
2) one of the types in Figures H.50 to H.99 4) if they are non threaded;
3) other connections may be mounted provided that the automatic change over device is sold with a fixed outlet tube;
1) A range of 49 figures has been reserved for each type of connections However, the needs of this document do not use all this range
2) A range of 49 figures has been reserved for each type of connections However, the needs of this document do not use all this range.
3) A range of 49 figures has been reserved for each type of connections However, the needs of this document do not use all this range.
4) A range of 49 figures has been reserved for each type of connections However, the needs of this document do not use all this range.
4) future types will be acceptable providing they are not interchangeable with the connections specified in this European Standard, and providing their assembly gives an equivalent degree of safety
Tables G.1, G.2 and H.1, H.2 show, for information, the inlet and outlet connections used in the various countries depending on their use
The automatic change over devices shall only incorporate a single outlet connection
The design of the connection shall ensure the soundness function of the connection under the assembly conditions specified in the instructions
If the union incorporates a seal it shall:
⎯ be mounted in such a way that it cannot fall off;
⎯ be easily replaced by a new seal, if necessary, without using special tools;
⎯ have a size in accordance with the indications given in annexes G and H;
⎯ be fixed onto the automatic change over devices so as to be subject to all the tests in this standard
No distortion or breakage shall be noticed and the automatic change over devices shall comply with the soundness test described in 5.5 after application of the forces defined in 5.4.1 and 5.4.2
In addition, the manufacturer's instructions shall specify the use of a spanner when this is necessary for fitting or removing the automatic change over devices.
Supply-reserve indicator
!The supply-reserve indicator, if any, shows which cylinder is in use via a signal related to the pressure at the automatic change over device outlet."
The supply-reserve indicator can either be integrated into the automatic changeover device or function independently If it operates independently, it must be connectable through suitable connections as illustrated in Figures G and H.
In any case it shall correspond to the automatic change over device used, in accordance with the manufacturer's users instructions.
Knob for selection of the operational cylinder
The automatic changeover device features a securely fixed knob to prevent accidental disassembly, ensuring safety and reliability This knob is designed without any sharp edges or parts, and it clearly marks the extreme positions for easy identification.
The positions of the knob shall enable an observer to see which cylinder is in use when he stands 2 m away
Fixing onto a wall
When the automatic change over device is designed to be fixed onto a wall, it shall be electrically insulated from this, in accordance with the specifications given in the instructions
To prevent gas leakage from the inlet connection during cylinder changes, it is essential to install non-return valves on each inlet of the automatic changeover device.
This requirement is considered as met if the leak observed, at the end of the test carried out under the conditions described in 7.2.4.2 does not exceed 200 cm 3 /h."
Mechanical strength
Resistance to pressure
5.4.1.1 The automatic change over devices shall be capable of resisting the pressure test described in 7.2.1.1 without rupture
5.4.1.2 The automatic change over devices shall be capable of resisting the pressure test described in 7.2.1.2, without rupturing the diaphragm
After these two tests, the device shall meet the soundness requirement specified in 5.5
5.4.1.3 The automatic change over devices shall be capable of resisting the pressure test described in 7.2.1.3 without rupturing at the level of the body/cover assembly.
Strength of connections
5.4.2.1 Strength of the union/automatic change over devices connection
The fixing of the inlet connection onto the automatic change over devices body shall withstand the following tests, under the conditions defined in 7.2.2:
⎯ a torque of at least 30 Nãm in both directions;
⎯ a bending moment created by a force of 400 N directed upwards and whose application point is at the base of the outlet connection (see Table 6);
The fixing of the outlet connection onto the automatic change over devices body shall resist the following tests, under the conditions defined in 7.2.2:
1) a torque of at least 30 Nãm in both direction;
In addition, for automatic change over devices of nominal DN diameter greater than or equal to 15 the two connections shall resist a torque of 100 Nãm
5.4.2.2 Strength of automatic change over devices when fitted onto its support
The automatic change over devices fitted to the installation as indicated in the instructions, shall resist the following tests, under the conditions defined in 7.2.2, Table 6: a) a torque in both directions:
1) of at least 20 Nãm for non threaded hose outlet connections;
2) see Table 2 for threaded connections and flanged connections
Table 2 — Torque applicable to threaded connections and to flanged connections
DN Torque for cylindrical threaded connections with elastomer joint
Torque for other threaded connections and flanges Nãm
A bending moment of 400 N is generated by a downward force applied at the base of the inlet connection Additionally, a tensile strength test of 2,000 N is conducted, although verification is not necessary for inlet connections that are screwed onto the valve.
The mechanical strength required shall be ensured whatever the position of fixing of the automatic change over device onto the installation.
Soundness
The automatic change over device shall be sound for all positions and all pressures less than those defined in 7.2.4.1
Soundness is deemed acceptable when the leak rate is below 15 cm³/h for automatic changeover devices with a nominal diameter of DN 15 or less, and below 30 cm³/h for those with a nominal diameter exceeding DN 15.
For an automatic changeover device with rapid connections, it is essential to ensure the integrity of the connections regardless of the mounting position Additionally, if the device is capable of rotation, the reliability of the connections must be maintained in all orientations, including during the rotation process.
Mechanical endurance
Under the conditions defined in 7.2.5.1, the automatic change over devices shall withstand 10 000 complete valve opening/closing cycles without mechanical failure and remaining sound in the sense of 5.5
After the endurance test, the operational requirements given in 6.2 and 6.3 shall be met.
Resistance to humidity changes
Any material likely to be altered by humidity shall be submitted to a test cycle for resistance to humidity changes as defined in 7.2.6
The increase in mass between the second and the first weighing shall not exceed 20 % of the initial mass
The change in mass between the first and the third weighing shall not exceed 5 % of the initial mass.
Resistance to corrosion
The complete device, not connected at the ends, is subjected to the tests defined in 7.2.7
Following the test, a visual inspection must show that there is no corrosion on components that could affect proper functioning, excluding any salt deposits from the test Additionally, the performance characteristics should continue to meet the specifications outlined in clause 6.
General
Introduction
Under the specified test conditions, the changeover device operation curves must remain within the pressure and guaranteed rate limits outlined in section 6.2 Additionally, these curves should not exhibit any anomalies that could suggest a fault.
Adjustable and variable change over devices shall comply with operating requirements of this standard in the regulated pressure range declared by the manufacturer
The range of an adjustable change over devices shall remain within a tolerance of ± 15 % of the nominal regulated pressure.
Supply pressure
Butane: minimum: 0,3 or p d + 0,2 if greater – Maximum: 7,5 bar
LPG: minimum: 0,3 or p d + 0,2 if greater – Maximum: 16 bar
Propane: minimum: 1 or p d + 0,5 if greater – Maximum: 16 bar
Operational limit characteristics (regulation function)
The maximum regulated pressure must not exceed 4 bar, regardless of the upstream "service" and "reserve" pressures specified in section 6.1 Additionally, for automatic changeover devices supplying appliances in accordance with EN 437, the regulated pressures must align with the values outlined in Table 3.
Table 3 — Pressure characteristics p Mg , p Mp , and p o based on nominal pressures specified in EN 437
Gas Automatic change over devices regulated pressure mbar
Appliance supply pressure mbar a) Appliance categories a) p d p Mg p Mp p 0 mbar p n p min p max
The data for propane, as outlined in EN 437, includes important pressure specifications for automatic changeover devices These devices supply appliances with pressures that may differ from those specified in EN 437 The regulated pressures are defined by the equations: \$p_0 = 1.3 \times p_d\$, \$p_{max} = 1.2 \times p_d\$, and \$p_{min} = 0.50 \times p_d\$ Additionally, these automatic changeover devices can be adjustable to accommodate various installation requirements, ensuring optimal performance for appliances.
EN 437 (see 4.2) the regulated pressures are those given in Table 4:
Table 4 – Regulated pressures for automatic change over devices which supply a regulator (bar)
Definition of the pressure Numerical application given for information
Maximal pressure (service) p max(o) = p d × 1,2 3,60 1,80 1,20 0,90 0,60 0,48 0,36 0,18 Minimal pressure (reserve) p min (r) = p d × 0,50 1,50 0,75 0,5 0,375 0,25 0,20 0,15 0,75 with another device p min (r) = p d× 0,50 × 0,8 a) 1,20 0,60 0,40 0,30 0,20 0,16 0,12 0,06 a) To take into account the pressure loss of the limitor downstream the automatic change over devices.
Operational limit characteristics (Change over function)
Change over pressure
The difference between the minimum service regulated pressure and the maximum reserve regulated pressure shall be greater than 15 % of the nominal regulated pressure
In a two-stage automatic changeover device, the primary focus is on the regulated pressures of the first stage, which are essential for the changeover function The key regulated pressure to consider is the nominal changeover pressure, denoted as \( p_{di} \).
Selection of the operating cylinder
All the operational requirements described in 6.1, 6.2, 6.3.1 and 6.3.2 shall be met in either of the two positions of the knob
General conditions
Type of test gas
The automatic changeover device can be tested with air at a temperature of (20 + 5) °C or reference propane, except for the soundness test, which must be conducted using air.
Reference propane, classified as G 31 in EN 437:2003, is defined in relation to dry air as specified in the same standard The equivalence ratio between air and propane is determined by the formula: \$ q_n(\text{air}) = 1.2454 \, q_n(G \, 31) \$, where the flow rates of air and propane are measured in liters per hour (l/h).
Test conditions
Unless stated otherwise tests shall be carried out at a room temperature of (20 + 5) °C, which remains constant during each test
All measurements are corrected to reference conditions: 15 °C, 1 013,25 mbar.
Equivalence formulae
The mass rate of the gas indicated on the automatic changeover devices can be calculated under reference conditions using the formula: \$\frac{\rho}{\rho}\$.
The mass rate of the gas under reference conditions, denoted as \$M_g\$, is measured in kilograms per hour (kg/h) The volume rate, represented as \$q_n\$, is the measured volume of the reference gas, expressed in cubic metres per hour (m³/h), and is adjusted to align with the reference conditions specified in section 7.1.2 using the appropriate formula.
The actual volume rate measured, denoted as \$q_{\text{measured}}\$, is expressed in cubic meters per hour (m³/h) This measurement is influenced by the temperature (\$t\$) in degrees Celsius (°C) and the atmospheric pressure (\$p_a\$) in millibars (mbar) Additionally, the density of the reference gas under standard conditions (\$ρ\$) is measured in kilograms per cubic meter (kg/m³), as outlined in sections 7.1.1 and 7.1.2 Furthermore, the density of the average liquefied petroleum gases used for the appliance (\$ρ_g\$) is also expressed in kilograms per cubic meter (kg/m³), as referenced in section 3.2.
Test samples
!For tests six identical devices shall be tested in the order specified in Table 5
After those tests the devices shall be dismantled and requirements of 5.1 to 5.3 shall be checked visually and dimensionally." ˜Table 5 — Order of tests™
Clause Test Automatic change over devices number
Verification of constructional characteristics
Resistance to pressure
During the whole duration of the tests described in 7.2.1.1, 7.2.1.2 and 7.2.1.3, the temperature of the automatic change over devices and of the supply water shall be maintained at (50 + 2) °C
NOTE Tests intended to be carried out with water may be carried out with air or with nitrogen provided that adequate safety measures are taken
!When the device has a safety valve, these tests shall be carried out in accordance with Annex A."
7.2.1.1 An automatic change over device is connected in turn by one of its inlet to a pipe supplied with water, the diverter valve being directed to the sense of supply After reaching the required temperature, the outlet connection is blocked and the pressure of water is increased to 1,75 times the maximum supply pressure (p a), the test shall not last less than 15 min after the application of the pressure
The changeover device is linked to a pipe that supplies air or nitrogen Once the desired temperature is achieved, the pressure of the air or nitrogen is raised to 1.5 times the regulated pressure, with a minimum of 0.5 bar The testing duration must be at least 15 minutes, during which the leak rate at the regulator should not exceed 50 cm³/h.
At the end of this test, the requirements of 5.3.1 and 5.4.2 shall be met."
An alternative automatic changeover device is linked to a water-supplied pipe, with its inlet connection, vent, and any atmospheric openings sealed For testing, the diaphragm can be punctured to enable unrestricted water flow.
Once the necessary temperature is achieved, the water pressure is raised to the maximum supply level The test must continue for at least 15 minutes following the pressure application This procedure aims to assess the mechanical strength of the cover and body assembly, and any leakage at the joints will not be considered during the evaluation.
At the end of this test, the requirements of 5.4.1.3 shall be met."
7.2.1.4 When a second regulation is integral to the automatic change over device, the manufacturer shall give to the laboratory the intermediate pressure values corresponding to its device, and tests shall be carried out as follows:
⎯ in accordance to 7.2.1.1 by applying 1,75 times the supply pressure, through the inlet connection;
⎯ in accordance with 7.2.1.2 by applying 1,5 times the maximum pressure given by the manufacturer at the first stage regulation outlet;
⎯ in accordance with 7.2.1.1 by applying 1,75 times the maximum pressure given by the manufacturer through the second stage regulation inlet;
⎯ in accordance with 7.2.1.2 by applying 1,5 times the maximum regulated pressure through the second stage regulation outlet, by neutralizing each time the appropriate upstream or downstream regulation.
Mechanical strength of connections
Tests for mechanical strength shall be carried out using a dynametric device allowing the measurement of forces to an accuracy of within ± 5 %
For the torque test a system which neutralizes bending moments should be used (if a torque wrench is used it is desirable that this is two handed)
!For threaded connections, the checks of 5.4.2 shall be carried out with the change over device installed in accordance with the manufacturer’s instructions."
For flanged connections in accordance with ISO 7005-2 the tightening force to be applied to the flange nuts is given in Table 6 ˜Table 6 — Tightening of bolts as in ISO 7005-2™
The duration of application of the torques and forces shall be 1 min
The corresponding requirements of 5.4.2 shall be met.
Soundness
During the whole duration of the tests described in 7.2.1.1, 7.2.1.2 and 7.2.1.3, the temperature of the automatic change over devices and of the supply water shall be maintained at (50 + 2) °C
NOTE Tests intended to be carried out with water may be carried out with air or with nitrogen provided that adequate safety measures are taken
!When the device has a safety valve, these tests shall be carried out in accordance with Annex A."
7.2.1.1 An automatic change over device is connected in turn by one of its inlet to a pipe supplied with water, the diverter valve being directed to the sense of supply After reaching the required temperature, the outlet connection is blocked and the pressure of water is increased to 1,75 times the maximum supply pressure (p a), the test shall not last less than 15 min after the application of the pressure
The changeover device is linked to a pipe that supplies air or nitrogen Once the desired temperature is achieved, the pressure of the air or nitrogen is raised to 1.5 times the regulated pressure, with a minimum of 0.5 bar The testing duration must be at least 15 minutes, during which the leak rate at the regulator should not exceed 50 cm³/h.
At the end of this test, the requirements of 5.3.1 and 5.4.2 shall be met."
An additional automatic changeover device is linked to a water-supplied pipe through its outlet The inlet connection, vent, and any other openings to the atmosphere are sealed For testing purposes, the diaphragm can be punctured to enable the unrestricted flow of water.
Once the necessary temperature is achieved, the water pressure is raised to the maximum supply level The test must continue for a minimum of 15 minutes following the pressure application This procedure aims to assess the mechanical strength of the cover and body assembly, and any leakage at the joints will not be considered during the evaluation.
At the end of this test, the requirements of 5.4.1.3 shall be met."
7.2.1.4 When a second regulation is integral to the automatic change over device, the manufacturer shall give to the laboratory the intermediate pressure values corresponding to its device, and tests shall be carried out as follows:
⎯ in accordance to 7.2.1.1 by applying 1,75 times the supply pressure, through the inlet connection;
⎯ in accordance with 7.2.1.2 by applying 1,5 times the maximum pressure given by the manufacturer at the first stage regulation outlet;
⎯ in accordance with 7.2.1.1 by applying 1,75 times the maximum pressure given by the manufacturer through the second stage regulation inlet;
⎯ in accordance with 7.2.1.2 by applying 1,5 times the maximum regulated pressure through the second stage regulation outlet, by neutralizing each time the appropriate upstream or downstream regulation
Tests for mechanical strength shall be carried out using a dynametric device allowing the measurement of forces to an accuracy of within ± 5 %
For the torque test a system which neutralizes bending moments should be used (if a torque wrench is used it is desirable that this is two handed)
!For threaded connections, the checks of 5.4.2 shall be carried out with the change over device installed in accordance with the manufacturer’s instructions."
For flanged connections in accordance with ISO 7005-2 the tightening force to be applied to the flange nuts is given in Table 6 ˜Table 6 — Tightening of bolts as in ISO 7005-2™
The duration of application of the torques and forces shall be 1 min
The corresponding requirements of 5.4.2 shall be met
The valve pad is securely positioned within its housing inside a pressurized container filled with liquid propene, ensuring that the entire assembly is fully immersed, such as having 50 ml of liquid in a 200 ml container.
After 72 h at (20 ± 5) °C, the container is emptied, the valve and its housing are taken out
Upon removal from the container, the assembly must be inspected within ten minutes to ensure it meets the specifications outlined in section 5.3.2 regarding the valve.
7.2.4.1 Soundness of the automatic change over devices
This test can be carried out according to the methods used in the laboratories provided that these methods give results that can be reproduced
The measurement error shall not exceed 5 cm 3 /h
In the event of disagreement the method described in annex D shall be used
The automatic changeover device is sequentially connected to an air supply pipe at pressures of 150 mbar, 8.25 bar for butane devices, and 17.5 bar for propane and LPG devices The outlet connection is sealed, and the diverter valve is positioned to align with the supply direction.
The test shall last for not less than 2 min, after reaching the pressure
The automatic changeover device is connected via its outlet to a pipe that supplies air at a pressure of 1.5 times the regulated pressure, with a minimum requirement of 150 mbar, while ensuring that the two inlet connections are sealed.
The requirements of 5.5 shall be met
This test shall be carried out with a 0,4 mm injector connected to the outlet connection allowing air to flow constantly through the test
Each inlet connection shall be supplied in turn with air at pressures of 300 mbar and 8,25 bar for butane,
For propane, the pressure levels are 1 bar and 17.5 bar, while for LPG mixtures, they are 300 mbar and 17.5 bar It is essential to verify the integrity of the opposite non-return valve using the manual changeover device in both the supply and reserve positions.
The requirements of 5.3.8 shall be met."
Endurance
7.2.5.1 Automatic change over devices endurance
The automatic changeover device connects both inlets to an air supply of 1.4 bar for butane and 7.5 bar for propane and LPG, operating at a temperature of (20 ± 5) °C.
The flow rate is adjusted to 20 % of the guaranteed rate
10 000 cycles are carried out, consisting of: a) interruption of the outlet flow to induce lockup; b) restoration of the outlet flow; c) every 10 cycles the manual change-over valve is alternated
Each cycle should allow the diaphragm to flex and for the valve to be held on its seat for 1 s Minimum cycle time shall be 5 s
The requirements of 5.6 shall be met."
Resistance to humidity changes
A sample is taken of any material capable of being altered in its structure and dimensional characteristics by humidity
It is submitted to the following test cycle:
⎯ drying in an oven at 50 °C for 12 h;
⎯ weighing to an accuracy of 0,1 mg;
⎯ immersion in distilled water at 20 °C for 24 h;
⎯ removal from the water, superficial removal of the excessive water with filter paper;
⎯ weighing to an accuracy of 0,1 mg;
⎯ drying in an oven at 50 °C for 24 h;
⎯ weighing to an accuracy of 0,1 mg
At the end of this test, the requirements of 5.7 shall be met.
Resistance to corrosion
The automatic changeover device, which is not connected at the ends, is tested in accordance with ISO 9227 Alternative testing methods that yield equivalent results, such as the one outlined in informative annex I, are also permitted.
The device is positioned according to the manufacturer's instructions within a steady-state test chamber and is left for 96 hours Upon completion of this duration, it is expected to meet the requirements outlined in section 5.8.
Verification of performance characteristics
General
Tests shall be carried out whilst maintaining the device and gas at the temperatures shown in Table 7 ˜Table 7 — Regulation curves - Supply conditions™
Performance tests must be conducted in all potential mounting positions for the automatic changeover device during installation These tests, along with the soundness test, should be performed both prior to and following the endurance test.
Performance tests can be carried out using calibrated orifices or using rate meters which enable the obtaining of a full range of rates up to the guaranteed rate
When using the rate meter method, the measurement is determined by the integral number of turns of the volume meter C1, which divides the volume recorded by the elapsed time.
When utilizing the calibrated injector method to measure rates, the regulated pressure of the automatic changeover device is recorded for each injector or group of injectors at a specific upstream setting.
The value indicated on the rate-pressure curve of the injectors reflects the corresponding rate These values establish an operational point for the automatic changeover device based on the downstream pressure Collectively, these points create the regulation curve for the specified upstream pressure.
NOTE The !lock up pressure" is measured 5 s after effective closing
To ensure accurate results, the diameter of the pipework supplying the injectors downstream of the device under test must be sufficiently large to prevent pressure drops.
Whatever the method used tests are carried out with increasing rates from 0 to the guaranteed rate, then for decreasing rates
The network of the rate-pressure curves, corresponding to each of the injectors used, is shown on a same graph The requirements of 6.2 shall be met
V1, V2 Ball valves (DN ≥ inlet DN of R3, minimum DN 10)
P1, P2 Measuring devices of upstream pressure (class 0,1)
R3 Automatic change over device under test
P3 Measuring device of downstream pressure (class 0,1)
C1 Flow rate measuring device d ≥ outlet DN of R3, minimum DN 10
NOTE The supply device (R1/V1, R2/V2) is given as a guide a) volume rate method
P1, P2 Measuring devices of upstream pressure (class 0,1)
R3 Automatic change over devices under test
P3, P4 Measuring devices of downstream pressure (class 0,1)
NOTE The supply device (R1/V1, R2/V2) is given as a guide b) calibrated injectors method (principle)
Plotting of regulation curves
The regulation curves are plotted for the supplied values listed in Table 7, corresponding to each inlet and the various positions of the manual knob changeover.
In each case the other inlet supply shall not be connected
With those four curves, the requirements of 6.2 and 6.3.2 can be checked
In case of two stages automatic change over devices, the requirements of 6.3.2 are checked on the curves of regulated pressure of the first stage (change over function)
General
All instructions, information, and warnings on the device and its packaging must be provided in the official language(s) of the country where the device will be sold.
Marking of the device
The automatic change over device shall carry in a durable, legible and visible fashion the following information:
⎯ manufacturer's name or logo and, possibly, trademark;
⎯ marking in letters or figures allowing the identification of the automatic change over device;
⎯ type of gas: butane, propane or LPG;
⎯ maximum and minimum supplied pressures expressed in bars (bar);
⎯ nominal regulated pressure, expressed in millibar (mbar) or bar (bar);
⎯ change over nominal pressure, in case of two stage automatic change over devices expressed in millibar (mbar) or bar (bar);
⎯ guaranteed rate in kilograms per hour (kg/h);
⎯ date of manufacture indicated by the last two figures of the year;
⎯ where necessary, an arrow to show the direction of the flow of gas
Any additional information given by the manufacturer shall not lead to confusion with the information required by this standard.
Packaging
Automatic changeover devices must be safeguarded against foreign material intrusion through packaging that clearly specifies the gas type, the nominal regulated operating pressure, and any usage limitations, particularly regarding the designed connection type for these devices.
Instructions for use and maintenance
Each automatic change over devices shall be accompanied by instructions intended for the user, which, in addition to the items in 8.2, shall specify:
- manufacturer's address and, if necessary, his agent;
- assembly conditions, in particular the preferred position recommended by the manufacturer and the instructions concerning the use of a spanner;
- installation, safety and soundness conditions, in particular with regard to the seals and their good condition;
The automatic changeover devices have an estimated life expectancy of 10 years Therefore, it is advisable to replace them within 10 years from the date of manufacture to ensure optimal performance and safety.
When installing the device outdoors, it must be positioned or protected to prevent direct exposure to trickling water Additionally, the installation guidelines specify the necessary conditions for isolating automatic changeover devices mounted on walls, along with essential details for installing a supply-reserve indicator.
- a description of the operation of the safety devices (see annex A)
It is crucial to adhere to current regulations regarding the installation of safety devices, particularly to prevent leakage risks during cylinder changes.
If the instructions are printed on the automatic change over devices packaging, they shall be easily removable so that they may be kept by the user
Special requirements for automatic change over devices fitted with pressure or rate operated safety valves
Change over devices fitted with an over-pressure relief
Definition
An over-pressure relief device is designed to discharge gas when the pressure exceeds a predetermined level, automatically opening to the outside It closes once the monitored pressure falls back to normal levels, ensuring safety during regular operation.
Constructional characteristics
The relief shall be integral with the automatic change over device
The pressure sensing subassembly of the automatic changeover device does not require a measuring device Additionally, the set point adjustment must be safeguarded to prevent unauthorized modifications.
In designs utilizing a pressure sensing subassembly for gas discharge, it is crucial to select the cross-sectional area of the valve and connecting pipework to the atmosphere to prevent any unacceptable pressure increases within the pressure subassembly.
The device must include a component for connecting to a relief, such as an Rp 1/8 internal thread, to facilitate external discharge when the automatic changeover device is installed indoors Additionally, the discharge orifice should be shielded from rainwater, and the tube leading to the atmosphere can also function as a vent.
The guidelines must indicate that external connections should be made when using an automatic changeover device equipped with a relief in a residence They should include all essential details regarding this connection, particularly the tube's dimensions, including maximum diameter and length.
Performance characteristics
A.1.3.1 Automatic change over devices having a maximum regulated pressure of up to and including 150 mbar
The opening pressure of the relief shall be between 2 times the nominal regulated pressure and 150 mbar, for ambient temperatures between -20 °C and + 50 °C
Automatic change over devices designed to operate with pressures of 112/148 mbar shall not be fitted with a relief valve
A.1.3.2 Automatic change over devices having a maximum regulated pressure exceeding
The valve shall operate in compliance with the regulations in force in the country of destination of the appliance.
Test methods
The valve undergoes internal soundness tests, operational behavior assessments, and discharge verifications, while all strength and external soundness tests are conducted according to the specifications for the automatic changeover device.
A.1.4.1 Automatic change over devices having a maximum regulated pressure of up to and including 150 mbar
Tests shall be carried out under the following conditions:
⎯ Internal soundness test before opening
The regulated pressure is elevated to 1.4 times the nominal level during testing, which is conducted at a room temperature of (20 ± 5) °C The relief system is deemed sound if the measured leak rate is below 15 cm³/h, indicating satisfactory performance.
⎯ Behaviour in operation and discharge
At ambient temperatures of (-20 ± 2) °C, (+20 ± 5) °C, and (+50 ± 2) °C, the regulated pressure can rise to 150 mbar The relief mechanism is designed to activate between twice the nominal pressure and 150 mbar When reaching the upper limit of 150 mbar, the gas release rate must be no less than 0.1 m³/h (air, under reference conditions).
⎯ Internal soundness test after reclosing
After the valve is opened and then reclosed, the pressure must decrease to 1.4 times the nominal regulated pressure, and the integrity must be checked under the same conditions as prior to the opening.
A.1.4.2 Automatic change over devices having a maximum regulated pressure exceeding
The manufacturer's specifications shall be verified based on the information given to the test laboratory.
Automatic change over device marking
In addition to the information required in 8.2, the automatic change over device fitted with a relief valve shall carry the opening pressure.
Automatic change over device fitted with an over-pressure shut off safety valve
Definition
Shut off device, trigged by an excessive regulated pressure, which causes the complete shut off of the gas flow for all values of supply pressure
The restoration of the gas flow shall only be possible by manual intervention when the conditions which cause the shut device to operate have disappeared
The automatic change over device's manual device which enables the restoration of the gas flow is called resetting device.
Constructional characteristics
The shut-off device can be either built into the automatic changeover device or function as a separate component Regardless of its configuration, the construction requirements for the shut-off device align with those of the automatic changeover devices.
The shut-off device must be equipped with an independent restrictor, a dedicated measuring device, and its own measuring pipework, ensuring that these components are not affected by the operation of an overpressure relief system.
The resetting device shall be protected against any intervention which could impair the operation of the over pressure shut off
The force required to close the valve from the open position must be at least equal to the maximum gas pressure resistance and the weight of the internal components, in addition to five times the frictional force.
The closing device must exert a closing force that is at least equal to the maximum supply pressure, the weight of the internal components, and twice the frictional force when in the closed position.
The diaphragm shall be designed and/or incorporated in such a way that it withstands, after setting, a pressure equal to the maximum supply pressure.
Performance characteristics
A.2.3.1 Automatic change over devices with a maximum regulated pressure of up to and including 150 mbar
The device must halt gas flow when the downstream pressure, measured after the automatic changeover device, is between twice the nominal regulated pressure and 150 mbar, regardless of the operating conditions.
Automatic change over devices designed to operate with pressures of 112/148 mbar shall not be fitted with an over pressure shut off device
A.2.3.2 Automatic change over devices with a maximum regulated exceeding 150 mbar
The device must adhere to the regulations applicable in its destination country and is designed to shut off the gas flow at pressures between 2 to 3 times the nominal regulated pressure.
Test methods
A.2.4.1 Test for the components transmitting the closing forces
The frictional force is measured with the closing spring removed and the valve in the open position
Prior to testing, the mechanism is held at (20 ± 5) °C for 24 hours
The valve is moved in the closing direction, the force needed to initiate the motion is recorded
The test is first carried out at atmospheric pressure then at the maximum supply pressure
The highest closing force is the retained value
First a performance test as defined in A.2.4.3 shall be carried out at (20 ± 5) °C
The diaphragm of the shut off device shall then be subjected to a test pressure equal to the maximum supply pressure
This pressure shall be maintained for 10 min
A subsequent performance test will be conducted as outlined in A.2.4.3, ensuring that the operating pressures do not deviate by more than 10% from the values recorded in the previous test.
A.2.4.3.1 Automatic change over devices with a maximum regulated pressure of up to and including
Tests shall be carried out at (20 ± 5) °C
The device under test is supplied with compressed air through its outlet connection The supply pressure is increased up to the pressure at which the device energizes
At the time of the shut off, the pressure shall be below 150 mbar
After shut off, check that the gas flow remains cut off at any pressure below the maximum supply pressure
The test will be conducted again under the extreme temperature and pressure conditions outlined in Table 7, confirming that the operating pressure values fall within the tolerances specified in section A.2.3.1.
A.2.4.3.2 Automatic change over devices with a maximum regulated pressure exceeding 150 mbar
The manufacturer's specifications shall be verified based on the information given to the test laboratory.
Automatic change over device fitted with an under-pressure shut off safety device
Definition
An under-pressure shut off safety device is a crucial component of the automatic change over device, responsible for completely stopping gas flow at all regulated pressure levels specified in A.3.2 This shutdown can occur due to a lack of gas supply upstream of the automatic change over device or an excessive gas flow rate downstream.
The components which provide control may also provide the safety function
The restoration of the gas flow shall only be possible by manual intervention when the conditions which cause the safety device to operate have disappeared
The automatic change over device's manual device which enables the restoration of the flow is called the resetting device.
Constructional and performance characteristics
The device shall cut out the gas flow only when the pressure measured downstream of the automatic change over device is at least equal to p Mg
The resetting device must prevent any permanent gas flow opening during an impact when in the closed position It should be designed to remain either fully open or fully closed without manual intervention Additionally, if the device functions as a stopcock with a rotating handle, the gas shut-off direction must be clockwise.
To ensure the proper functioning of the automatic changeover device, it must be safeguarded from any interference that could disrupt its normal operation during a reset, especially if the setting device serves no other purpose and is easily accessible.
Test methods
Tests shall be carried out at (20 ± 5) °C
The device under test being in the closed position, check that the gas rate remains shut off for any pressure below the maximum supply pressure
The device under test is initially provided with compressed air and calibrated to the specified rate at maximum supply pressure Subsequently, the supply pressure is decreased to the level at which the device activates.
At the time of the cutout, the regulated pressure must meet or exceed the minimum pressure required at the device's inlet or the inlet of the subsequent regulator.
Check then that the cut out is maintained when the supply pressure is raised up to the upper limit
After each shut off out check for soundness.
Automatic change over devices fitted with an excess flow valve
Definition
The excess flow valve is a crucial component of the automatic changeover device, designed to shut off gas flow when the rate exceeds the guaranteed limit.
The restoration of the gas flow shall only be possible by manual or automatic intervention, when the conditions which caused the safety device to operate have disappeared
For manual devices, an automatic changeover mechanism, such as a resetting device or valve, is essential for restoring flow and is typically suitable for this type of system.
Performance characteristics
The excess flow valve is designed to stop the gas flow whenever there is a disconnection of the flexible hose located downstream of the automatic changeover devices This mechanism activates in response to any increase in the gas flow rate.
The automatic changeover devices can operate at 120% to 200% of the guaranteed rate, with an angle tolerance of ±10° relative to their axis in the fixed positions on the cylinder, across the entire temperature ranges specified in Table 7.
Automatic resetting devices are allowed a maximum residual leak of 30 g/h to 60 g/h, as per national regulations, when positioned at zero flow to facilitate the resetting process.
For manual re-setting devices, a maximum residual leak between 15 cm 3 /h and 200 cm 3 /h according to the national regulations, is permitted
The presence of the device shall not modify the automatic change over device's performance
For optimal performance of an automatic changeover device, it is advisable to use a two-position tap This tap should have one position for full opening and another for complete closure to ensure that the excess flow function remains unaffected.
In any case the excess flow rate shall ensure its function and the shut off valve shall carry a marking allowing the identification of the direction of closure.
Complementary tests for the automatic change over devices – Test methods
A.4.3.1 The performance tests for the excess flow valve shall be carried out at the following operating temperatures:
The closure caused by the excess flow valve shall occur in the range defined between 120 % and 200 % of the guaranteed flow rate
A.4.3.2 After the tests for resistance to pressure and mechanical strength of the connection, carried out as described in 7.2.1 and in 7.2.2, the operation of the excess flow valve shall remain satisfactory at the temperatures given in A.4.3.1
A.4.3.3 For the endurance test, the device shall be subjected to a series of 1 000 cycles of opening/closing, without change in the operating forces, of the sensitivity of the positioning devices and without apparent traces of pitting This test shall be carried out at ambient temperature.
User and maintenance instructions
The manufacturer must clearly specify in the instructions the type of cylinder compatible with the automatic changeover device Additionally, when using a cylinder, it is essential to outline the limitations of use beyond the requirements stated in clause 8.
⎯ do not move the cylinder during use;
⎯ close the cylinder valve in the event of operation of the excess flow valve;
Only open the valve after addressing the device's operational issues If the valve has intermediate positions, it must remain fully open to enable the pressure limiter's function Additionally, the automatic changeover device includes an excess flow valve that ensures proper shut-off.
120 % and 200 % of the guaranteed flow rate; e) way of operating the automatic change over device; f) instructions for installation.
Automatic change over devices fitted with a regulated pressure limiter
Definition
The device is an integral component of the automatic changeover system, designed to prevent pressure from exceeding a predetermined limit during a failure, all while maintaining the gas flow uninterrupted.
Constructional and performance characteristics
A.5.2.1 The pressure limiter may be either integral in the automatic change over device or an immovably attached component to it In any cases, the pressure limiter is fitted downstream the regulation system and the construction requirements applicable to it are the same as those applicable to the automatic change over device
A.5.2.2 As long as the pressure upstream of the pressure limiter is below the maximum regulated pressure the device does not operate as a pressure limiter
If the upstream pressure surpasses the maximum regulated pressure, the pressure limiter will ensure that the regulated pressure does not exceed 120% of this maximum value, regardless of the flow rate.
Moreover, a mechanism can be provided to put in evidence the intervention of the pressure limiter (for instance, pressure nipple or independent indicator)
A.5.2.3 In addition, the pressure limiter shall not show a pressure drop exceeding 30 % of the nominal regulated pressure of the single automatic change over device.
Test methods
To verify the construction and performance characteristics of the pressure limiter, the manufacturer must supply the testing facility with all necessary equipment to assess the functionality of the pressure limiter, including its regulation capabilities and potential failures.
A.5.3.2 Measurement of the maximum regulated pressure
The automatic changeover device must ensure that the maximum regulated pressure does not exceed 120% of the maximum regulated pressure for any flow rate up to 120% of the guaranteed rate.
A.5.3.3 Measurement of the pressure drop
The automatic changeover device is provided in accordance with A.5.2.3 and is connected to a differential pressure measuring device both upstream and downstream Its characteristics are verified to ensure compliance with the standards outlined in A.5.2.3.
Users and maintenance instructions
In addition to the indications given in 8.4, the instructions shall give all information on the function and operation limits of the pressure limiter
In particular, the instructions shall specify that this device shall not be fitted downstream a automatic change over devices incorporating an integral pressure limiter
! Special requirements for automatic change over devices and automatic change over device systems for caravans, motor caravans or fresh water boats
An automatic changeover device system will be provided either as a complete assembly or as a kit of parts that, when assembled, will comply with the requirements of this European Standard.
Automatic change over devices and change over device systems for use in seawater boats are dealt with in Annex J
This annex applies to vehicles or boats equipped with appliances in category I3B/P(30) that are powered by LPG cylinders, adhering to the temperature and pressure ranges outlined in Clauses 1 and 6.
In the following text "caravan" is used either for caravan or freshwater boats
The kit must be designed for easy and correct assembly, minimizing the chances of incorrect installation If special tools are required, they should be included in the kit After assembly and installation, the system's operation and integrity must be verifiable through testing Additionally, clear and comprehensive instructions for both assembly and testing should accompany the kit.
Flexible hoses used in the system shall meet the requirements of prEN 1763
The length of flexible hoses used shall be in accordance with EN 1949
The connections in the automatic changeover device system must be specifically designed to avoid compatibility with devices not intended for use within the system, ensuring that components cannot operate independently.
The inlet and outlet connections must adhere to Annex D of EN 12864:2001, while any intermediate connections should differ from the system's inlet and outlet connections if the assembly is designed to be disassembled.
The assembly features a fixed-type regulator in accordance with EN 13785 Testing of this regulator will be conducted following the procedures outlined in EN 13785, utilizing the pressures specified by the manufacturer.
The regulated pressures shall be in accordance with Annex D of EN 12864:2001
The nominal rate shall not be greater than 1,5 kg/h
The automatic change over device or the automatic change over device system shall incorporate a safety device limiting pressure as in Annex D of EN 12864:2001
Cylinder mounted regulators used in change over device systems shall meet the resistance to impact requirements of EN 12864, with the outlet connection protected
Automatic change over devices and automatic change over devices systems complying with this annex shall carry in a durable, legible and visible fashion the marking "Caravan(e)"
In addition when the two stages of regulation are identified separately:
⎯ first stage of regulation shall only indicate the values of the supply pressure as information on the pressure;
⎯ second stage of regulation shall only indicate the regulated pressure 30 mbar as information on the pressure;
⎯ nominal rate shall be indicated in the information of the second stage of regulation
The instructions shall include a warning of the type "Only for use in caravans, motor caravans and freshwater boats"
The caravan automatic change over devices or systems must include a warning stating, "This automatic change over device (system) is not suitable for mobile homes." Additionally, the requirements outlined in section 5.3.6 are not mandatory for these automatic change over devices and systems.
Special requirements for low pressure automatic change over devices under extreme temperature conditions (temperatures below - 20 °C)
Any automatic change over devices which may be used under extreme temperature conditions (temperatures below - 20 °C) shall meet the following requirements:
The automatic change over devices is left at a temperature of - 40 °C for 24 h
Its temperature is then raised to - 30 °C
After this, the automatic change over devices shall meet at - 30 °C all the specifications requested in this standard at - 20 °C
Automatic changeover devices that comply with this annex must include, alongside the information specified in section 8.2, a clear indication of their suitability for extreme temperature conditions, marked with a notation such as "- 40 °C".
This information shall also be shown in the users and maintenance instructions
Method for measuring leaks at test pressures less than or equal to 16 bar