Wolter RA-series tube fans are centrifugal fans with circular connections at inlet and outlet sides. Both sides can easily be fitted into the tube by means of RSV fastening clamps. The performance curves in this catalogue have been established using the inlet test method in the test chamber according to DIN 24163 / AMCA 210 Figure 12, installation type D - Ducted Inlet, Ducted Outlet. The curves indicate the static pressure increase Δpst as a function of the volume flow.