air flow vs pressure

What succeeds if the fans type QK/QR work in not described conditions of pressure in the diagrams air flow/pressure?

What succeeds, in particular, if they work in condition of inferior pressure to that indicated?

Hello,
the fans type QK/QR did not run outside the described diagramm
in worst case the fans are pumping

when the duty point is lower than the fan curve
the fan will bring more volume und pressure as you need
you kann see this new duty point direktly on the fan curve

please, show me your duty points
i will select for you the best fan
and show the curve incl. the duty point

best regards