Abstract: This suction arm for gaseous fluids comprises a tubular articulated conduit consisting of at least one flexible sleeve (5) disposed between two rigid tubes (8). These tubes (8) are interconnected at either end of the flexible intermediate sleeve (5) by mechanical holding means (9) comprising each at least one pair of first and second members (10a, 10b) pivotally interconnected centrally of the flexible sleeve and rigidly assembled in side by side relationship by distance-pieces (15) under the control of a spiral return spring (13) and detent-positioning means (16, 17, 18), whereby the two rigid tubes (8, 8) are constantly urged to their relative angular position matching that of the ends of the intermediate flexible sleeve (5).