In a message dated 11/23/03 5:18:57 PM Pacific Standard Time, fabric.sul@terra.com.br writes:
How is the pressure in a 1 atm sub controlled using a rebreather inside the sub? Does it have an over pressure relief? How is this gas that is coming out the rebreather system purged from the pressure hull, so that there isn't an increase in cabin pressure?
Greatly oversimplified: If it's a semi-closed circuit system the excess pressure is vented using a compressor (only shallow depth tourist subs as far as I've seen). In a closed circuit system, oxygen is only added at more or less the rate that it's converted to CO2 by respiration and adsorbed by the scrubber, so the pressure stays the same.
Shawn