A note on slide raft inflation
The escape slides do not have an inflation bottle big enough to fully inflate the slide. Instead, the bottles, when triggered by opening the door in auto, blow through a venturi which sucks the ambient air into the slide. An anti-deflation valve traps the resultant mass of air in the inflation chambers. Its a simple system with one moving part.
The downside is that, inflated underwater, the slide cannot fully inflate, and sucks in some water during the inflation sequence. This is why the 737 slides are not also rafts. A slightly better intake location on widebody slides allows them to double as rafts.