Equipment fitted with forced or induced draught burner(s) shall be fitted with devices for proving adequate air flow during the pre-purge, ignition and operation of the burner. Air flow failure at any time during the pre-purge, ignition or operation of the burner shall cause safety shut-down and, in the case of no operator supervision, shall cause a lockout.

This function shall meet the requirements of the protective system according to 5.7.2 and 5.7.3.

The air-proving device shall be checked in the ‘no flow’ state prior to start-up (e.g. by stopping the combustion air supply or by interrupting the air signal to the device(s) in such a way as to simulate stopping the combustion air supply). Failure to prove the device in the “no flow” condition shall prevent start-up. [Footnote 1]

Air flow shall be monitored:

• by pressure detectors or

• by flow detectors.

It has to be shown that any of these devices provide satisfactory and reliable proof of the flow for all operating conditions.

This requirement shall not apply to portable gas burners, work station burners and equipment-integrated burners with open flame, supervised continuously by trained operators, and having a maximum burner input rating below 70 kW.

Air pressure detectors shall comply with EN 1854.