I wondered if anyone could help, I work in the fire protection industry. We currently have a project using a pressurised cylinder. The cylinder hold 200 lites of water plus 40 litres of nitrogen gas as a propellant at 10.0 bar. I’m trying to work out once the 200 litre water volume has been expelled what would be the remains pressure. I believe the formula to use is Boyles law but I’m struggling to understand. Would appreciate it if anyone could help.