BS EN 676:2020 pdf download
BS EN 676:2020 pdf download.Forced draught burners for gaseous fuels.
4.22 Design
4.2.2.1 Combustion
The design and construction of the burner shall be such that within the intended input range and within the prescribed pressure range, the used fuel gas is burned completely and safely.
The burner head may be lengthened as long as the performance of the burner is not affected in an unsafe manner. The geometry of the mixing device and its position in the burner flame tube shall remain unchanged.
4.2.2.2 Mechanical safety, stability and control devices
Moving parts shall be shielded if the enclosure provided does not ensure adequate protection. See also
4.3.1.
The construction of the burner shall be in such a way that no instability, distortion or breakage likely to impair its safety can occur.
Levers and similar devices which have to be operated by the installer or user shall be appropriately identified.
Constructional parts accessible during use and nsaintenance shall be free from sharp edges and corners that might cause damage or personal injury during use or maintenance.
The design of the burner shall be such that It can be handled safely. It shall be designed and packaged so that it can be stored safely and without damage.
Where the weight, size or shape of the burner or its components prevents them from being moved by hand, they shall be litted with means to lift them easily.
4.2.3 Accessibility for maintenance and use
Burners that can be withdrawn or swivelled out of position without the use of tooLs shall be interlocked (for example, by means of limit switches) In such a way that they cannot be operated in the withdrawn or swivelled position.
The interlock device shall be equipped with positive mode actuation of EN ISO 14119:20 13 and the related part of the control system shall not be less than category 1 in accordance with EN ISO 13B491.
4.2.4 Soundness
Boles for screws, studs, etc. intended for the assembly of parts shall not open into gas bearing parts and components. The wall thickness between drillings and gas bearing parts and components shall be at least 1 mm. This requirement shall not apply to orifIces for measurement purposes or to components within the burner head.
The soundness of parts and assemblies making up the gas circuit and likely to be dismantled during regular maintenance in situ shall be achieved by means of mechanical joints, for example metal•tometal joints, gaskets, or 0-ring joints, but excluding the use of all sealing materials such as tape, paste or liquids. All sealing materials shall remain effective under normal conditions of burner use.
4.2.5 MaterIals
It is recommended that materials are selected to optimize product durability and lifetime and that considerations are made to avoid the selection of rare or hazardous materials.
It is recommended that considerations are made using recycled or reused materials, and to the selection of materials which can then be subsequently recycled.
It is recommended that the possibility of marking components to aid to their sorting for disposal/recycling at end of life may be reviewed.
The quality and thickness of the materials used In the construction of the burner shall be selected In such a way that the constructional and performance characteristics of the system do not deteriorate during operation. In particular, all the components of a burner shall withstand the mechanical, chemical and thermal loads that may be encountered during operation. Under normal conditions of use, maintenance and adjustment, they shall not show any changes that could affect their normal functioning.
lithe housing contains any metal parts not made of corrosion-resistant material, these shall be suitably protected with an effective anti-corrosion coating.
If aggressive media is used, the materials used shall be resistant to this media. Asbestos or asbestos-containing materials shall not be used.
Copper shall not be used for gas carrying parts where its temperature Is likely to exceed 100 °C. Solder that has a melting point below 450°C after application shall not he used for gas carrying parts.
The pipework material shall comply with EN ISO 3183:2012, EN 10216-1:2013, EN 10217-1:2002 or EN 10220:2002, as appropriate.
4.2.6 Mounting
The burner shall be designed in such a way that it can be effectively mounted on the heat generator.
The burner components shall be arranged and secured in such a manner that their correct operating position, and above all, the correct position of the burner orifices, cannot change during operation. The correct operating position shall he maintained when accessories are dismantled and re-fitted.
Parts of the burner that are not Intended to be set, adjusted or manipulated by the user or Installer shall be sealed.
Components requiring regular maintenance shall be arranged or designed so that they are easily detachable. Furthermore, incorrect replacement shall be prevented by design or. when this Is not possible, by marking and/or instructions.
4.2.7 Connections
Inlet connections with pressure-tight joints made on the threads, connections within the burner with pressure-tight joints made on the threads that are not loosened for maintenance, and connections for parts that are not frequently dismantled and re-fitted shall be designed in accordance with ISO 7-1:1994.
