The gauge on an H cylinder of O2 reads 2000 psig. Approximately ...

[aabwk4]

The gauge on an H cylinder of O2 reads 2000 psig. Approximately how long would the contents of this cylinder last, until completely empty, at a flow of 6 L/min?
 
  a. 1 hr 30 min
  b. 17 hr 30 min
  c. 18 hr 10 min
  d. 21 hr 50 min

Question 2

Under what conditions will the gauge pressure of a cylinder of N2O accurately represent its con-tents?
 
  1. When the liquid in the cylinder has completely vaporized
  2. When the ambient temperature exceeds the critical temperature
  3. When the filling density is less than 1.0 (water-filled)
  a. 1 and 2 only
  b. 1 and 3 only
  c. 2 only
  d. 1, 2, and 3

[poopface]

Answer to Question 1

ANS: B
Once the factor for a given gas and cylinder is known, calculating the duration of flow is a sim-ple matter of applying the following equation:
Duration of flow (min) = Pressure (psig)  Cylinder factor/Flow (L/min)

Answer to Question 2

ANS: C
Should a cylinder of nitrous oxide warm to 97.5 F (its critical temperature), all the contents would convert to gas. Only at this temperature and above does the cylinder gauge pressure accu-rately reflect cylinder contents.