Key-fill vaporizer adaptor with overfill protection

Abstract

An apparatus is disclosed for converting vaporizers such as the Drager.TM. model 19 from pour-fill to safer indexed key-fill, and for providing overfill protection. A hollow screw is screwed up into an existing screw hole underneath the vaporizer that opens into the fluid storage compartment. A banjo encircling the screw provides two channels, one to dispense filling fluid up around the screw and into the vaporizer, and one to carry decompressing air back from the hollow through the screw. Each channel is connected to a separate pipe that communicates with a channel in an adaptor base screwed onto the vaporizer, and thereby to an indexed ISO key block connected to the fill bottle. Fluid thus flows from the bottle to the vaporizer and decompressing air flows back. For overfill protection, a special plug is fashioned to screw up into the existing sight glass access hole, and overfilling fluid flows from the vaporizer to the sight glass and then through the plug into the base where it exhausts. The sight glass continues to function accurately as a level indicator. During vaporizer use a block end plug covers the fill fluid, exhaust, and air decompression holes on the base, so there is no unwanted fluid escape.