Question 1

During inspection of the shoulder of a compressed gas cylinder, you note an asterisk (*) next to the test date. This indicates what about the cylinder?

Accepted Answer

An asterisk (*) next to the test date indicates DOT approval for 10-year testing.

Question 2

What is the primary purpose of indexed connector systems?

Accepted Answer

These safety systems make misconnection between pieces of equipment nearly impossible.

Question 3

Unlike CO₂ or N₂O, O₂ cannot be stored as a liquid at room temperature but must be kept in special cryogenic containers. Why is this so?

Accepted Answer

Oxygen has a critical temperature well below room temperature (-181.4° F [-118.6° C]). Liquid O₂ must continually be stored below this temperature, or it reverts to its gaseous state.

Question 4

You are planning a patient transport that will take approximately 1 hr. The patient requires manual ventilation with 10 L/min of O₂. What is the minimum number of full E cylinders you would take with you?

Accepted Answer

An E cylinder contains about 680 liters of oxygen. At a flow rate of 10 L/min, the patient will use 600 liters in 1 hour (10 L/min x 60 min). Therefore, one full E cylinder is sufficient for the transport. However, it is always advisable to have a backup, so taking 2 cylinders is the minimum recommended.

Question 5

The pressure of O₂or air in a bulk supply system is reduced to what standard working pressure?

Accepted Answer

The gas pressure in a central piping system normally is reduced to the standard working pressure of 50 psig at the bulk storage location.

Question 6

What is the pin index hole position for O₂?

Accepted Answer

The pin index hole position for O₂ is 2 and 5. This is determined by the alphanumeric code, where the first digit represents the pin position for the oxygen connection (1), the second digit represents the pin position for the nitrous oxide connection (2), the third digit represents the type of gas (B for oxygen, M for nitrous oxide), the fourth digit represents the pin index hole position for oxygen (1), the fifth digit represents the pin index hole position for nitrous oxide (2), the sixth digit represents the type of gas (S for oxygen, N for nitrous oxide), the seventh digit represents the pin index hole position for oxygen (1), and the eighth digit represents the pin index hole position for nitrous oxide (0).

Question 7

Which of the following statements is FALSE about PISS standards?

Accepted Answer

The exact positions of pins and pinholes vary for each gas. Unless the pins and holes align perfectly, the yoke nipple cannot seat in the recessed valve outlet. Six holes and pin positions constitute the total system. Because overlapping holes cannot be used, there are 10 possible pin combinations.

Question 8

Why are zone valves incorporated into a hospital's central gas piping systems? 1) To terminate O₂delivery to an area in case of fire 2) To allow selective maintenance without shutting the system down 3) To allow variable pressure reduction throughout the system

Accepted Answer

Zone valves in a hospital's central gas piping systems are incorporated primarily for safety and maintenance reasons. They allow for the termination of gas delivery to specific areas in case of a fire (1) and enable selective maintenance or repairs without the need to shut down the entire system (2). Variable pressure reduction is not typically a function of zone valves; thus, option (3) is not a reason for their incorporation.

Question 9

What safety system is designed to prevent accidental interchanging among low-pressure (<200 psig) connectors such as those found on flowmeters and ventilators?

Accepted Answer

DISS (Diameter Index Safety System) is a standardized safety system designed to prevent accidental interchanging among low-pressure connectors, such as those found on flowmeters and ventilators, with a maximum pressure of 200 psig. It uses a unique combination of thread diameter, pitch, and thread form to ensure that connectors with different gases do not fit together. Therefore, it ensures the safety of gas delivery in the healthcare industry. Neither PISS nor ASSS is a recognized safety system, and CGA (Compressed Gas Association) is an organization that sets standards for compressed gases but does not specifically deal with low-pressure connectors.

Question 10

What is the indexed safety system for threaded high-pressure connections between large compressed gas cylinders and their attachments?

Accepted Answer

Adopted in the United States and Canada, the ASSS provides standards for threaded high-pressure connections between large compressed gas cylinders (sizes F through H/K) and their attachments.

Question 11

What is the greatest potential problem with quick-connect DISS systems?

Accepted Answer

Various manufacturers have designed specially shaped connectors for each gas Because each connector has a distinct shape, it does not fit into an outlet for another gas, and each manufacturer has its own unique design.

Question 12

One cu/ft of liquid O₂is the equivalent to approximately how many cu/ft of gaseous O₂?

Accepted Answer

Because 1 L of liquid O₂ weighs 2.5 lb and produces 860 L of O₂ in its gaseous state, the amount of gas in a liquid O₂ cylinder can be calculated with the following formula:

Question 13

You must connect a large-volume nebulizer to a bedside compressed-air outlet through a flowmeter. You have only standard O₂ flowmeters available. Which of the following actions is appropriate?

Accepted Answer

To avoid stocking a large variety of pressure regulators, flowmeters, and connectors for special gas use, adapters can be used to convert various DISS connections so that they can be used for a different purpose.

Question 14

Which of the following components are common to a standard compressed gas cylinder manifold system?
1) Automatic switch-over control
2) Pressure-reducing valves
3) Primary and reserve bank
4) Alarm system

Accepted Answer

A standard compressed gas cylinder manifold system typically includes an automatic switch-over control to automatically change from an empty cylinder bank to a full one, pressure-reducing valves to control the gas pressure, a primary and reserve bank for continuous gas supply, and an alarm system to alert when the primary bank is depleted or if there are any issues with the system.

Question 15

What do the components of a liquid O₂ bulk storage tank include? 1) Inner and outer steel shells, separated by a vacuum 2) Safety system that vents O₂ if warming occurs 3) Vaporizer system that converts liquid O₂ to gas 4) Pressure-reducing valves to lower pressure to 50 psig

Accepted Answer

The components of a liquid O₂ bulk storage tank include an inner and outer steel shells, separated by a vacuum, a safety system that vents O₂ if warming occurs, a vaporizer system that converts liquid O₂ to gas, and pressure-reducing valves to lower pressure to 50 psig. Therefore, option C is correct.

Question 16

The NFPA standard for bulk liquid O₂ systems requires that the reserve supply be which of the following?

Accepted Answer

Among the key provisions in these standards is the requirement for a reserve or backup gas supply to equal the average daily gas use of the hospital.

Question 17

Which of the following are true about ASSS standards?
1) They provide specifications for more than 60 gases and mixtures.
2) They apply only to cylinders sizes F through H/K.
3) They apply to high-pressure connections.
4) They provide a separate connector for all gases.

Accepted Answer

The answer of Which of the following are true about...

Question 18

Where do respiratory therapists typically find DISS connections?
1) At the outlets of pressure-reducing valves attached to cylinders
2) At the nurse station
3) At the station outlets of central piping systems
4) At the inlets of blenders, flowmeters, ventilators, and other pneumatic equipments

Accepted Answer

Respiratory therapists typically find DISS connections at the outlets of pressure-reducing valves attached to cylinders, the station outlets of central piping systems, and at the inlets of blenders, flowmeters, ventilators, and other pneumatic equipment. They would not typically find them at the nurse station. Therefore, the best choice is C, which includes options 1, 3, and 4.

Question 19

Which device is used to reduce the pressure and control the flow of a compressed medical gas?

Accepted Answer

If control of both pressure and flow is needed, a regulator is used.

Question 20

Structural requirements for the central piping systems that are used in hospitals to distribute gases are established by whom?

Accepted Answer

Structural standards for piping systems are established by the NFPA and are described in more detail elsewhere.

Quiz 40: Storage and Delivery of Medical Gases

During inspection of the shoulder of a compressed gas cylinder, you note an asterisk (*) next to the test date. This indicates what about the cylinder?

What is the primary purpose of indexed connector systems?

Unlike CO2 or N2O, O2 cannot be stored as a liquid at room temperature but must be kept in special cryogenic containers. Why is this so?

You are planning a patient transport that will take approximately 1 hr. The patient requires manual ventilation with 10 L/min of O2. What is the minimum number of full E cylinders you would take with you?

The pressure of O2 or air in a bulk supply system is reduced to what standard working pressure?

What is the pin index hole position for O2?

Which of the following statements is FALSE about PISS standards?

Why are zone valves incorporated into a hospital's central gas piping systems? 1) To terminate O2 delivery to an area in case of fire 2) To allow selective maintenance without shutting the system down 3) To allow variable pressure reduction throughout the system

What safety system is designed to prevent accidental interchanging among low-pressure (<200 psig) connectors such as those found on flowmeters and ventilators?

What is the indexed safety system for threaded high-pressure connections between large compressed gas cylinders and their attachments?

What is the greatest potential problem with quick-connect DISS systems?

One cu/ft of liquid O2 is the equivalent to approximately how many cu/ft of gaseous O2?

You must connect a large-volume nebulizer to a bedside compressed-air outlet through a flowmeter. You have only standard O2 flowmeters available. Which of the following actions is appropriate?

Which of the following components are common to a standard compressed gas cylinder manifold system? 1) Automatic switch-over control 2) Pressure-reducing valves 3) Primary and reserve bank 4) Alarm system

What do the components of a liquid O2 bulk storage tank include? 1) Inner and outer steel shells, separated by a vacuum 2) Safety system that vents O2 if warming occurs 3) Vaporizer system that converts liquid O2 to gas 4) Pressure-reducing valves to lower pressure to 50 psig

The NFPA standard for bulk liquid O2 systems requires that the reserve supply be which of the following?

Which of the following are true about ASSS standards? 1) They provide specifications for more than 60 gases and mixtures. 2) They apply only to cylinders sizes F through H/K. 3) They apply to high-pressure connections. 4) They provide a separate connector for all gases.

Where do respiratory therapists typically find DISS connections? 1) At the outlets of pressure-reducing valves attached to cylinders 2) At the nurse station 3) At the station outlets of central piping systems 4) At the inlets of blenders, flowmeters, ventilators, and other pneumatic equipments