# Oxygen Tank Duration

Oxygen tank duration calculation approximates how much time is left in an oxygen tank based on oxygen flow settings.

Duration of Flow = Oxygen Tank Conversion Factor * Remaining Tank Pressure (psi) / Continuous Flow Rate (L/min)

## Oxygen Cylinder Conversion Factors

• D Tank = 0.16

• E Tank = 0.28

• G Tank = 2.41

• H/K Tank = 3.14

• M tank = 1.56

## Duration of Flow

## Oxygen Duration Exam Questions

**1. **A size D cylinder of oxygen has a remaining pressure of 1200 psi. The patient’s flow rate is 3 L/min. When will the tank be completely empty?

A. 45 min

B. 1 hour 19 min

C. 1 hour 5 min

D. 1 hour 30 min

**Answer: C.**

**2. **A size G cylinder of oxygen has a remaining pressure of 2000 psi. The patient’s flow rate is 10 L/min. When will the tank be completely empty?

A. 10 hours 10 min

B. 9 hours 8 min

C. 8 hours 2 min

D. 5 hours

**Answer: C.**

**3. **Correctly match the Oxygen cylinder conversion factor to correct tank size.

A. D tank = 3.14, E tank = 0.28, G tank = 2.41, H tank = 0.16

B. D tank = 0.16, E tank = 0.28, G tank = 2.41, H tank = 3.14

C. D tank = 0.28, E tank = 0.16, G tank = 3.14, H tank = 2.41

D. D tank = 0.16, E tank = 2.41, G tank = 0.28, H tank = 3.14

**Answer: B.**

**4.** A patient states his E tank cylinder only lasted 1 hour at a flow rate of 2LPM. What psi of oxygen was in his tank?

A. 1000 psi

B. 378 psi

C. 429 psi

D. 1240 psi

**Answer: C.**

## Liquid Oxygen Duration Test Questions:

- Duration: Oxygen remaining in liquid O
_{2}cylinder in**min** - Capacity: Liquid O
_{2}in cylinder in**L** - Factor to convert liquid to gaseous O
_{2} - Reading on cylinder (example 0.33)
- Flow: O
_{2}flow rate**L/min**

**1. **The liquid capacity of a home liquid oxygen system is 40 Litres. The home care patient uses the system for 8 hours during sleep at a flow of 3 L/min. How many days with the home oxygen system last?

A. 24 days

B. 29 days

C. 42 days

D. 12 days

**Answer: A.**

**2. **If the capacity of a liquid oxygen cylinder in 4.0 L and the reading on the gauge is ⅓ full. How long with the liquid oxygen last if the flow is at 2 L/min.

A. 567 min

B. 766 min

C. 340 min

D. 102 min

**Answer: A.**