KST – KROMSCHRÖDER SYSTEM TECHNOLOGY
220.127.116.11 Mixture pipework
The mixture pipework volume shall be as small as possible. The system shall be designed so as to provide a sufficiently high mixture flow velocity such that flame propagation upstream cannot occur, or shall be fitted with a flame trap/arrestor or pressure relief devices.
Alternatively, the system shall be fitted with a sensor which causes lock-out in the event of the flow velocity falling below a pre-determined limit or a temperature sensor which causes lock-out in the event of flash-back (see 3.48).1)
These devices are not required for burners where the manufacturer can demonstrate that flash-back cannot occur in any circumstances (e.g. pilot burners with their own mixing devices).
The following chapters are printed with the permission of the DIN Deutsches Institut für Normung e.V. (German Institute for Standardization). For the implementation of the DIN Standard, the version with the most recent issue date is deemed authoritative. This is available from Beuth Verlag GmbH, Burggrafenstrasse 6, 10787 Berlin, Germany.
Our note on this Standard:
1) The flow velocity in the air circuit can be detected using a differential pressure switch. An adequate air flow rate also ensures a corresponding flow velocity in the mixture pipe.