Program: Respiratory Therapy
Course: Introduction to Respiratory Sciences
Lesson: Gas Physics
Handle Gas Cylinders With Care
Lesson: Gas Physics
Major Student Performance Objective -Lecture
The student will be able to discuss and demonstrate the gas laws and physics used
in the field of respiratory care.
Supporting Student Performance Objectives - Lecture:
Lesson: Gas Physics
• Describe Avogadro’s Law relating to a mole of oxygen and its dimensions.
• Relate Dalton’s Law to the partial pressure of oxygen in the atmosphere and in the lung.
• Recall concentration of O2 in the atmosphere and the lung.
• Apply the alveolar air equation.
• Relate ideal gas laws to situational use of gas delivery.Discuss agencies that regulate gas administration.
• Recall color codes mandatory for E cylinders.
• Differentiate between safety systems and when used.
• Demonstrate recognition of cylinder markings.
• Calculate duration of flow for E, G, and H cylinders.
• Recall cylinder capacities for E, G, and H cylinders.
• Demonstrate safe cylinder handling.
Supporting Student Performance Objectives - Lecture Continued:
Lesson: Gas Physics
• Discuss cylinder testing.
• Recall the difference between liquid and gaseous O2.
• Differentiate between single stage, multi-stage, preset, and adjustable flow meters.
• Differentiate between compensated and uncompensated flow meters.
• Make necessary adjustments when using an oxygen flow meter to deliver helium/oxygen mixtures.
• Describe the function and advantages/ disadvantages of the Bourdon Gauge.
Supporting Student Performance Objectives - Lecture Continued:
Lesson: Gas Physics
Lesson: Gas Physics
Major Student PerformanceObjective -Laboratory
The student will be able to operate Oxygen Supply Systems, Liquid Oxygen Systems, and
Oxygen Concentrators.
• Correctly select an “E” or “H” cylinder for use.
• Correctly maneuver a medical gas cylinder on and off a cylinder cart.
• Demonstrate the correct handling of a cylinder and cart on level ground.
• Properly prepare a cylinder for attachment of a reducing valve or gas delivery device.
• Correctly demonstrate the process of bleeding a reducing valve before removal.
• Demonstrate how to prepare an air/oxygen blender for use.
Supporting Student Performance Objectives - Laboratory:
Lesson: Gas Physics
Gases
Molecules continuously moving
Avogadro’s Law 1 gram of any substance has
6.02 x 1023 known as a mole 1 mole of a gas at STP =
22.4 Liters
Lesson: Gas Physics
Pressure
PB = Barometric Pressure 760 mmhg 14.7 PSI 1034 cmH2O
Water vapor (or humidity) exerts pressure
PH2O at 100% humidity at body temperature = 47 mmhg
Dalton’s Law Individual partial pressures = Total Pb = PN2 + PO2 + P trace gases
Lesson: Gas Physics
Concentrations of Gases in the Air
Oxygen 20.95%
Nitrogen 78.08%
Argon 0.93%
Carbon Dioxide 0.03%
Trace Gases 0.01%
Lesson: Gas Physics
Boyle’s Law
If temperature and mass are constant, volume and pressure are inversely proportional.
P1V1 = P2 V2
Lesson: Gas Physics
Charles’ Law
If pressure and mass are constant, temperature and volume are directly proportional.
V1 = V2
T1 T2
Lesson: Gas Physics
Gay-Lussac’s Law
If volume and mass remain constant, pressure and temperature are directly proportional.
P1 = P2
T1 T2
Lesson: Gas Physics
Relationships of Gas Laws
Lesson: Gas Physics
Volume
Boyle’s Charles’m(constant)
Pressure Temperature
Gay-Lussac’s
Gas Laws/Temperature
All gas laws use temperature in Kelvin (known as absolute scale)
C + 273 = Kelvin
Lesson: Gas Physics
Agencies Agencies Regulating Gas Administration
Department of Transportation - DOT Health and Human Services - HHS
• Food and Drug Administration - FDA Occupational Safety and Health
Administration - OSHA
Recommending Bodies Compressed Gas Association - CGA National Fire Protection Association -
NFPA Committee of American National
Standards for Anesthetic Equipment Z-79
Lesson: Gas Physics
Safety Systems for Cylinders
Color Coding
Pin Index Safety System
American Standard Safety System
Diameter Index Safety System
Lesson: Gas Physics
Qualities of Cylinder Gases
Flammable Gases ethylene cyclopropane
Nonflammable Gases nitrogen carbon dioxide helium
Gases that support combustion
oxygen oxygen mixtures nitrous oxide
Lesson: Gas Physics
Qualities of Oxygen
Fractional DistillationColorless
Odorless
Tasteless
Atomic Weight = 16 gms
Molecular Weight = 32 gms
Critical Temperature -118.8 C or -181.1 F and 49.7 atm
Above this temperature, it cannot
remain a liquid
Lesson: Gas Physics
Cylinder Marking and Testing
Front: DOT-3AA: DOT specifications
and service pressure Serial Number Ownership markings Manufacturer’s mark
Back: Original hydrostatic testing Specifications Retest dates Inspector’s marks
Cylinders are filled to 5/3 maximum pressure every 5-=10 years
Lesson: Gas Physics
Cylinder Handling
Keep in carrier or stand.
No flames/no smoking.
Proper technique in attaching regulators.
Store with cap to prevent breaking stem.
Cylinder testing
Lesson: Gas Physics
Lesson: Gas Physics
Major Student Performance Objective -Lecture
The student will be able to discuss and demonstrate the gas laws and physics used
in the field of respiratory care.
Supporting Student Performance Objectives - Lecture:
Lesson: Gas Physics
• Describe Avogadro’s Law relating to a mole of oxygen and its dimensions.
• Relate Dalton’s Law to the partial pressure of oxygen in the atmosphere and in the lung.
• Recall concentration of O2 in the atmosphere and the lung.
• Apply the alveolar air equation.
• Relate ideal gas laws to situational use of gas delivery.Discuss agencies that regulate gas administration.
• Recall color codes mandatory for E cylinders.
• Differentiate between safety systems and when used.
• Demonstrate recognition of cylinder markings.
• Calculate duration of flow for E, G, and H cylinders.
• Recall cylinder capacities for E, G, and H cylinders.
• Demonstrate safe cylinder handling.
Supporting Student Performance Objectives - Lecture Continued:
Lesson: Gas Physics
• Discuss cylinder testing.
• Recall the difference between liquid and gaseous O2.
• Differentiate between single stage, multi-stage, preset, and adjustable flow meters.
• Differentiate between compensated and uncompensated flow meters.
• Make necessary adjustments when using an oxygen flow meter to deliver helium/oxygen mixtures.
• Describe the function and advantages/ disadvantages of the Bourdon Gauge.
Supporting Student Performance Objectives - Lecture Continued:
Lesson: Gas Physics
Lesson: Gas Physics
Major Student PerformanceObjective -Laboratory
The student will be able to operate Oxygen Supply Systems, Liquid Oxygen Systems, and
Oxygen Concentrators.
• Correctly select an “E” or “H” cylinder for use.
• Correctly maneuver a medical gas cylinder on and off a cylinder cart.
• Demonstrate the correct handling of a cylinder and cart on level ground.
• Properly prepare a cylinder for attachment of a reducing valve or gas delivery device.
• Correctly demonstrate the process of bleeding a reducing valve before removal.
• Demonstrate how to prepare an air/oxygen blender for use.
Supporting Student Performance Objectives - Laboratory:
Lesson: Gas Physics