Unit stop, fuel oil line purge should ( ).

After the unit is stopped and the oil fire of the heating furnace is all extinguished, the ( ) line should be blown in time.

( ) must be emptied before the unit is stopped.

Before the unit stops, it should be checked that ( ) is clear.

Before the unit is drained, it should be checked that ( ) is unblocked.

When the unit stops to drain oil, the last of the following pumps to stop is ( ).

Unit stops when the side line pump can be purged at ( ).

When the unit stops, turn down the amount of each return pump at the beginning of ( ).

When the unit stops, stop the side pump at ( ).

When the unit is stopped, the reflow pump in the ( ) middle section can be blown.

The "three doors" in the heating furnace "three doors and one plate" means ( ).

The following that do not belong to the "three doors and one plate" structure of the heating furnace are ( ).

The following options that are not part of the heating furnace "three doors and one plate" are ( ).

Heating furnace "three doors and one plate" in "one plate" refers to ( ).

The furnace will appear ( ) when the heating furnace flue baffle is open for too many hours.