You are administering anesthesia in a location that does not have an oxygen supply line. The E-cylinder that you are using reads 500 psig. Your oxygen flows are 10 L/min. Approximately how long does it take for your E-cylinder to empty

A full E-cylinder of oxygen contains 600 L of gas at a pressure of 2000 psig. Using Boyle law (P1 V1 = P2 V2 ) the volume of the paially depleted cylinder can be calculated, V2 = (P1 V1 )/P2 or V2 = (P1 /P2 ) x V1 . There is a quaer tank left, and therefore a quaer of 600 L, or 150 L. At 10 L/min, this volume of gas would last 15 minutes.