Evaluation of keyed fillers on TEC vaporizers.

Single and dual port versions of the keyed fillers fitted to TEC4 and TEC3 vaporizers, respectively, were examined. The single port filler performed satisfactorily, provided that it was correctly used and properly maintained. Design deficiencies in the dual-port keyed filler were found which accounted for many of the problems described by users. The keyed bottle adaptor could be improved by an increase in its length and the provision of two openings into the outer tube at the bottle end.