Exam 3 Compressed Gases and Vaporizers [7/1/2024] Flashcards
What are the 2 ways cylinders are used?Give examples of each
-
Primary source
- tank: taking off the wall source and using tank for transport.
-
Emergency source:
- if pipeline fails, then tanks on back of anesthesia machine can be used.
S2
Cylinders are marked by color in the US, what are the main colors?
- Green = Oxygen
- Blue = Nitrous
- Yellow = Air
- White = Suction
S2
PSI stands for
Pounds per square inch
S3
what is a non-liquifed gas?
a gas that does not liquefy at oridnary ambient temperatures regardless of the pressure applied
S3
What were examples of non-liquifed gases?
- Oxygen
- Nitrogen
- Air
- Helium
S3
What is liquifed gas?
- a gass that becomes liquid to a large extent in containers at ambient temperature and at pressures from 25-1500psi
S3
A liquified gas can become a liquid at ambient temperature and at pressures from ____- _____psi
- 25 to 1500 psi
S3
What were examples of liquified gases?
- Nitrous oxide
- Carbon dioxide
N2O is used more than CO2
S3
What does the government do with gas cylinders?
They create:
* rules for building compressed gas
* building cylinders
* checking pressure in the cylinders, and
* cleanliness
S4 lecture
What government agencies are involved with compressed gases used in the OR?
- FDA
- Department of Transportation [DOT]
- Department of Labor/OSHA
- National Fire Protection Association
S4
What does the FDA do for gas cylinders?
puirty of substance
S4
What does the DOT do for gas cylinders?
- marking
- labeling
- storage
- handling
Mark Handles Storage Label DOTS
| S4
What does the dept of labor/OSHA do for gas cylinders?
- employee saftey
if tank explodes and hits someone they get involved
S4
what does the national fire protection association do for gas cylinders?
- Gas combustion
Gasses [O2 esp] supports combustion [doesnt cause it]
S4
Name the components of the cylinder/tank:
- Body
- Check valve
- Handle
- Pressure Relief Device
S5-6
Body
What is the body of the cylinder made out of?
- Steel
- Steel Carbon Fiber
- Aluminum
S5
The body of the cylinder has what kind of base?
- Flat Base
- Concave Base
S5
Body
The body of the cylinder has a neck with what?
screw threads where tubing can be screwed on
S5
The cylinder/tank has a check valve. What is this made out of?
- Bronze
- Brass
S5
Where is the check valve located?
What is the function of the check valve?
- Location: The valve is attached to the neck of the cylinder.
- Function: allows refilling and discharge of gas
S5
O2 tanks are now refilled away from the facility.
What is used to open/close the cylinder?
- Handle
- Handles should be attached to EVERY cylinder
S6
What is another name for pressure relief device?
What is the function of the pressure relief device on the cylinder/tank?
- Another name: Safety Relief
- Function: It vents cylinder contents to the atmosphere if pressure increases to a dangerous level (overheating or filling)?
S6
The pressure relief device [safety relief] allow excess pressure out of cylinder via 3 different methods. List the 3 methods.
- Disc that bursts
- Fusible plug melts
- Valve opens
S6
How does the Pin Index Safety System (PISS) prevent the crossover of the wrong cable/tank into the wrong hanger?
- Holes on the cylinder valve positioned in an arc below the outlet part
- Pins on the yoke or pressure regulator are positioned to fit into these holes
S7
What is the purpose of the pin index safety system (PISS)?
- Prevents crossover of wrong cable/tank into the wrong hanger.
- Prevents turning on the wrong gas thinking it’s a different gas.
Example: if we have a pin in 2,5 and thats oxygen. That’s the pin located for every O2 tank in the US.
S7 lecture
- How are cylinder sizes labeled?
- What is the most common cylinder size on anesthesia machines?
- A (smallest) to H (largest)
- Cylinder size E on anesthesia machines
S8
What size cylinders are used for transport?
- Cylinder size D are used for transport
If we are Driving the pt somehwere, we need cylinder D
S8
Cylinders supply gas to the machine at approximately what pressure? And In order to supply pressure, the cylinder must remain ____.
- Pressure from cylinder to machine is approx 45 psi
- must remain closed
S8
with non-liqudiefied gas what happens to pressure as volume decreases?
- pressure decreases as volume decreases
S9
What is the content and pressure of the oxygen tank on an anesthesia machine in the following scenarios:
1. Full Tank:
2. Half Full
3. Quarter Full
4. Empty
-
Full Tank:
- 600L
- 1900 PSI (1900-2200)
-
Half Full
- 330L
- 950 PSI
-
Quarter Full
- 165L
- 475 PSI
-
Empty
* 0L
* 0PSI
With nonliquified gases, know how to determine how much time is left in a cylinder.
A tank contains 300L, and is running at 2L/min. How many hours can this tank last?
MATH:
1. Figure out how much is used per hour.
2. 2L/min x 60 min = 120L/hr
3. Divide avalible by whats needed
4. 300L/120LperHr = 2.5 hours
S9 lecture
For liquefied gases, what does the pressure depends on? What is the significance of this?
- Pressure depends on vapor pressure
- This makes pressure NOT an indication of remaining volume.
In a liquefied gases there is no relationship between PSI and volume
S10
Note the full and half tank of Nitrous, but tanks have a pressure of 745 psi. Pressure is not an indicator of volume for liquefied gase.
Nitrous
In Liquefied gases there is no relationship between PSI and volume. List the liquied gas PSI and volume [for math purpose]:
1. Full tank
2. Half tank
3. No liquid remaining
4. Near Empty
-
Full tank:
- 1590L
- 745 PSI
-
Half tank:
- 745 PSI
-
No liquid remaining
- 250L
- 745 PSI
-
Near Empty
- 125L
- 350 PSI
S10 lecture
- If the tank of nitrous has 1500L of volume, what is the PSI?
- A half full tank of nitrous, and giving 2L/min. How long will it last?
- PSI is 745 PSI
- Half Full is 750L.
- Using 120L/hr.
- 750L/120Lperhr = 6.25 hours
Since nitrous is a liquified gas, we need more information per Kane that she will provide on the test. For example, a full tank has 1500L then from there we can assume half would be 750. But memorize the picture.
What are the Department of Transportation (DOT) regulations for cylinders?
- Diamond shaped label indicating hazard of gas…danger, warning, or caution
- Expiration date of contents
- Name and address of manufacturer
- Test date
- Service pressure
DOTS looks for DENTS
S11
Cylinder Standards:
Valves, regulators, gauges never come into contact with what?
- Oil
- Grease
- Lubricants
Esp the neck, the safety relief, and on/off pin.
S12
Cylinder Standards:
Never subject cylinder to temps above ______
- 54 C (130 F)
S12
Cylinder Standards:
Never cross use what?
- Hoses
- Regulators
- Gauges
S12
Cylinder Standards:
What must not be altered?
- Original Markings on Cylinder
- Original Labels
S12
Other Cylinder Standards:
1. What should be ensured with connections?
2. What should not be done with a cylinder?
3. How should valve be kept?
4. properly secured to prevent what?
Other Cylinder Standards:
1. Connections are always tight
2. Cannot be dropped, drug, slid
3. Valve kept closed at all times
4. Properly secured to prevent fall
S12
Describe the conditions of storage rooms for cylinder tanks.
- Wrapping, drapes undesireable
- Full tanks separated from empty tanks
- Adequate ventilation
- Not exposed to corrosive chemicals, fumes
- Signs: “No smoking,” or “No Combustibles”
- Stored upright in bins
Storage should be W/FANSS
S13
Things to consider/do prior to using gas cylinders.
- Inspect: label, pin index holes, regulator, valve outlet
- Check if washer is in place
- Tampered seal removed
- Check service pressure
- Face valve outlet away from people
- Correct leaks
- Open the valve (slowly) to relieve excess pressure before bringing the cylinder to pt
- Open Slowly
Inspect Cylinder To Check For COO
S14
sorry i removed the bolding, i was editing it and it got messed up.
What are pipleline systems used for?
- used to deliver non-flammable gases (O2, air, nitrous) to anesthetizing locations and other pt care areas*
S15
What are the 3 main systems/pieces of pipeline system?
- Central supply
- Piping: recieved at 50psi
- terminal units: maintaines approx 50 psi
S15
Where are possible locations for the Central Supply?
- Outdoors in an enclosure
- Indoors in secure area
S16
A Central Supply “bank” must contain gas for at least how many days?
- 2 days
S16
Can the hospital have their 2 day bank of O2 supply in different locations?
- yes, can have primary and secondary bank
- may have reserve supply in secondary location
S16
What are the 2 types of oxygen supply source?
- Gaseous Supply
- Liquid Supply
S17
What is the purpose of Shut-off Valves?
- Permit specific areas of the piping system to be isolated for problems /maintenance.
- These are color coded.
S19
- The area alarm system must be in at least how many places?
- The area alarm system must be labeled for what?
- What places will have the gas alarm system?
- Are area alarms color coded?
- 2 places
- Must be labeled for gas and area
- The affected unit, critical life support area, maintenance, engineering
- Yes, these are also color coded.
S20
What are terminal units?
- Point in piped gas distribution where user connects and disconnects by hose
S21
What safety system does the terminal unit use?
- Diameter Index Safety System (DISS)
- DISS = Nipple and nut vary in bore and diameter
S21
- What allows convenient connection with one/both hands without tools to terminal units?
- Even though quick connected are convinient, what is the drawback to this?
- Quick Connectors
- Drawback: Quick Connectors leak more
S22
What is saturated vapor pressure (SVP)?
- When equilibrium is achieved b/w the liquid and vapor phases at a constant temperature from molecules hitting walls of container.
S27
Specific Heat of Water
- 1cal/g
- water is the standard.
S31
The Standard
How does a vaporizer dilute saturated vapor?
- Vaporizer dilutes saturated vapor by splitting gas flow.
- vaporizing chamber
- Bypass
- Ratio dependents on the size of the adjustable orifice
S34
Higher splitting ratio means more flow will go through vaporizing chamber, higher anesthetic gas delivery.
What are the two types of vaporizers?
- Flow-over (modern)
- Bubble through (older)
S34
Why is desflurane heated in the vaporizer when its boiling point is at room temperature?
- There is a lot of variability at room temperature.
- Desflurane is heated to a precisely controlled temperature and stable vapor phase.
- The heated vapor is then “injected” into the fresh gas flow to deliver a precise anesthetic concentration.
S35 [lecture?]
What object in the anesthesia machine counters the pumping effect?
- Machine Outlet Check Valve
S41 [idk where this is from]
Why will an increase in altitude not affect the delivery of Isoflurane or Sevoflurane?
- Isoflurane and Sevoflurane are not pressurized. They operate as a function of atmospheric pressure.
- At sea level, atm = 760 mmHg. This pressure keeps molecules down in the liquid phase.
- So, in higher elevations, there will be less atmospheric pressure. Which means more molecules can escape as a gas.
- The decrease in atmospheric pressure and the increase in the volume percent of gas will equal the partial pressure of gas delivered at sea level.
- Refer to the math below or watch the YouTube link.
- https://www.youtube.com/watch?v=UgViWCNVgOA&ab_channel=CountBackwardsFrom10
S43 [ANDY?]
