Oxygen supply systems quiz 3

the rules for handling compressed gas cylinders.

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regulations and codes affecting compressed gas cylinders in Hydrostatic Testing

1. type 3A, 3AA and 3AL cylinders are to be hydrostatically retested every five years (unless otherwise specified) to determine their expansion characteristics. If the cylinder received a stamped star following the test date that cylinder will not be reexamined again for ten years 2. hydrostatic retest pressures are to be five thirds the cylinders working pressure 3. The most common test used to determine the expansion characteristics for cylinders over 900 psi(g) is the water jacket volumetric expansion test 4. Permanent expansion is calculated (permanent expansion/total expansion x 100) to determine the wall thickness of the cylinder. Reduction in wall thickness can occur when the cylinder is physically damaged or is attacked by corrosion. 5. cylinders must also have an internal and external visual examination at the time of the retest 6. Compressed gas cylinders should be capable of holding up to 10% more than the maximum filling pressure marked. This added capacity is required because of variations in cylinder pressure that occur with changes in ambient temp. this is usually indicated with a "+" stamped into the shoulder of the cylinder following test date

Diameter Index Safety System

A system developed by the CGA to prevent the use of equipment intended for a specific gas being used on another gas. This system is similar to the ASSS except it is intended for equipment that is attached to gas sources of less then 200 psig

regulations and codes affecting compressed gas cylinders in Tank Content Identification (color code and label)

Air: Yellow or black and white Carbon Dioxide CO2 Gray Carbon Dioxide/Oxygen CO2/O2 gray and green Cyclopropane C3H6 orange Ethylene C2H4 red Helium He Brown Helium/oxygen He/O2 brown and green Nitrogen N2 Black Nitrous oxide N2O light blue Oxygen O2 Green or White

regulations and codes affecting compressed gas cylinders in construction

Construction of nonliquefied gas cylinders - compressed gas cylinders are constructed of seamless, high quality steel, chrome-molybdenum, or aluminum that is either stamped into shape using a punch-press die or spun into shape by wrapping heated steel bands around specifically designed molds. the bottom of the cylinder is welded closed and the top of the cylinder is threaded and fitted with a valve stem. the steel utilized in cylinders must meet the chemical and physical requirements of the DOT and are designated by type: 1. type 3 cylinders, which are made of low-carbon steel, are no longer produced. 2. type 3A cylinders are made of high carbon-steel (non-heat-treated) 3. type 3AA cylinders are made from heat-treated, high strength steel 4. type 3AL cylinders are constructed of specially prescribed seamless aluminum alloys.

regulations and codes affecting compressed gas cylinders in shoulder markings

Cylinder markings: 1. DOT (material used in construction) 2. 3AA (material used in construction) 3. 2015 (filling pressure 2015 psig) 4. N374839 (fist letter is the size and the rest is the serial number) 5. ARCO (Owner) 6. Manufacturer's Inspectors mark 7. SPUN CR-MO (method of manufacture) 8. 1 Symbol 80 (original safety test by mo/yr) 9. Star (doesn't have to be tested for 10 years) 10. + (can be filled 10% higher than it service pressure) 11. EE 20.1 (represents the elastic expansion in cubic centimeters used in testing)

diaphragm and piston type compressors.

Diaphragm compressors use a flexible diaphragm attached to a piston to compress gas. As the piston moves down, the diaphragm is bent outward, and gas is drawn through a one-way valve into the cylinder. Upward movement of the piston forces the gas out of the cylinder through a separate one-way outflow valve. Piston compressors use the action of a motor-driven piston to compress atmospheric air. The piston is seated within a cylinder casing and is sealed to it with a carbon or Teflon ring. As the piston retracts, atmospheric air is drawn in through a one-way intake valve. When the piston protracts, the intake valve closes and the gas is compressed before it leaves through a one-way outflow valve. A small gas reservoir is placed in a coiled tube to allow the hot, compressed gas to cool to room temperature before it is delivered to the output valve. The reservoir also removes some of the humidity from the intake gas. Usually a water drain is located near the compressor's output, and a water trap should be placed between the output and the device to be attached to the compressor to prevent problems with moisture accumulation

American Standard Safety System (large cylinders)

Large cylinders use a size configuration and thread indexed safety connection system. The shape of the gas outlet nipple receptacle, the diameter, and number of the threads is specified for each gas. The proper regulator has a nipple and hexnut with corresponding configuration and threading.

regulations and codes affecting compressed gas cylinders in Transportation

Medical gases can be classified as nonliquefied and liquefied. Nonliquefied gases are stored and transported under high pressure in metal cylinders. Liquefied gases are stored and transported in specially designed bulk liquid storage units. The design of compressed-gas cylinders, bulk storage containers, and their valve outlets, as well as their transportation, testing, and periodic examination, are subject to national standards and regulations.

statements concerning the properties of oxygen.

Oxygen is an elemental gas that is colorless, odorless, and tasteless at normal temperatures and pressures. It makes up 20.9% of the Earth's atmosphere by volume and 23.2% by weight. It constitutes approximately 50% of the Earth's crust by weight. Oxygen is slightly heavier than air, having a density of 1.326 kg/m3 at 21.1°C and 760 mm Hg (specific gravity = 1.105).1 At temperatures less than −183°C (−300°F), oxygen exists as a pale bluish liquid that is slightly heavier than water. Oxygen is classified as a nonflammable gas, but it readily supports combustion (i.e., the burning of flammable materials is accelerated in the presence of oxygen). Some combustibles, such as oil and grease, burn with nearly explosive violence if ignited in the presence of oxygen. 1 All elements except the inert gases combine with oxygen to form oxides; oxygen therefore is characterized as an oxidizer. The two methods most commonly used to prepare oxygen are the fractional distillation of liquid air and the physical separation of atmospheric air. The fractional distillation of liquid air, which relies on the Joule-Kelvin (or Joule-Thompson) effect, was introduced by Karl von Linde in 1907.2 Box 3-1 describes the fractional distillation process; Figure 3-1 illustrates the components of a typical fractional distillation system. The fractional distillation process is used commercially to produce bulk oxygen, which can be stored as a liquid in cryogenic storage tanks or converted into a gas and shipped in metal cylinders. The physical separation of atmospheric air is accomplished with devices that use molecular sieves and semipermeable membranes to filter room air. These devices, called oxygen concentrators, are used primarily to provide enriched oxygen mixtures for oxygen therapy in the home care setting.

Pin Index Safety System

Safety systmes - cylinder valves are built with indexed safety connections so that only the proper regulators for the gas contained can be used PIN INDEX SAFTEY SYSTEM (PISS) - used for small cylinders "A-E". PISS consists of two holes bored in assigned places in the valve with two corresponding pins on the yoke, the pin and hole positions are specified for each gas by the CGA

regulations and codes affecting compressed gas cylinders in pressure releases

The Bureau of Explosives requires that all cylinders contain a pressure-relief mechanism to prevent explosion. There are three types currently being used: 1. Rupture disks (aka called frangible disk) 2. Fusible plugs 3. Spring-loaded devices

Bulk Oxygen Supply Systems

The NFPA defines a bulk oxygen system as more than 20,000 cu. ft of gas. including unconnected reserves that are on hand at the site this can be liquid or gas Bulk system include a. insulated reservoir b. vaporizer with associated tubing attached to the reservoir c. pressure reducing valve d. pressure release valve

70-30% helium-oxygen mixture

This mixture will provide 1.6 times the flowrate indicated on an oxygen flowmeter. Therefore to determine the actual flowrate multiply the flowmeter, multiply the reading by 1.6. Conversely to determine the desired setting, divide the flowrate desired by 1.6 and set the meter on that reading. Example: To deliver 8 LPM of 70-30% heliox divide 8 LPM by 1.6 to determine the setting of the oxygen flowmeter 8 LPM / 1.6 = 5 LPM

80-20% helium-oxygen mixture

This mixture will provide 1.8 times the flowrate indicated on an oxygen flowmeter. For example, a 10 LPM reading on the flowmeter is actually providing an 18 LPM flowrate of the 80-20% heliox combination. Therefore to determine the actual flowrate multiply the flowmeter reading by 1.8 and to determine what flowmeter setting to use for a desired flowrate, divide the flowrate desired by 1.8 Example: To deliver 8 LPM of 80-20% heliox divide 8 LPM by 1.8 to determine the setting of the oxygen flowmeter 10 LPM / 1.8 = 4.4 LPM

Multi-State Regulators

a. can be preset or adjustable b. uses more than one pressure reduction chamber to drop source pressure to 50psi or lower if using an adjustable type multistage regulator. (used mostly for research)

Be able to calculate compressed gas cylinder duration.

a. full cylinder pressure b. full cylinder volume (in cubic feet) c. How many liters are in a cubic foot (1cu cm/ft =28.3L) L/psig=cu Ft. full x 28.3 L/cu. Ft. /psig full ex. 244 cu ft x 28.3 L/cu ft /2200 psig =3.14 L/psig

Single Stage Regulators

are the most common type we use. a. can be preset or adjustable b. preset types lower gas pressure from the higher source pressure directly to 50psi. Adjustable types lower gas pressure from the higher source pressure to the adjusted pressure (0-50psi)

Compensated and uncompensated flowmeter

c. pressure compensated - most Thorpe tube flowmeters used in respiratory care are pressure compensated. when restriction or high resistance device is attached to the outlet of a pressure compensated flowmeter the flow from the flowmeter is lowered but is reflected accurately on the flowmeter's calibrated scale. d. non-pressure compensated - when a restriction or high resistance device is attached to the outlet of a non-pressure compensated Thorpe tube flowmeter the reflected flow on the flowmeter scale is lower then the actual flow (it reads lower than what is actually coming out, the patient is getting more oxygen than we think)

fixed orifice flow restictors

fixed orifice = same size doesn't change - these quick connect devices are calibrated to deliver a set flow at a designated delivery pressure)

Pipeline Distribution System

gases stored in central supply systems are distributed to various sites or zones within a facility 1. Pipes must be seamless type K or L copper or standard weight brass 2. the gas contents of the pipeline must be labeled at least every 20 ft. and at least once in each room and or story 3. pressure regulating devices located between the bulk and pipeline must be capable of maintaining a minimum delivery pressure of 50 psi to all station outlets at the maximum gas flow. 4. a pressure relief valve should also be installed upstream of any zone valve to prevent excessive pressure in a zone where the shutoff valve is closed

Pre-Set and Adjustable Regulators

preset types lower gas pressure from the higher source pressure directly to 50psi. Adjustable types lower gas pressure from the higher source pressure to the adjusted pressure (0-50psi)

Fixed Orifice Flowmeters

pressure is adjusted against a fixed orifice, the higher the pressure the higher the flow. a. Bourdon flowmeters - are the most commonly used fixed orifice flowmeters in respiratory care. They are non-pressure compensated. When a restriction or high resistance device is attached to a fixed orifice flowmeter, the flow exiting from the device will be lower then the reflected flow on the flowmeter's scale.

Station Outlets

provide connections for gas delivery devices such as flow meters and mechanical ventilators. there outlets consist of a body mounted to the supply line, an outlet faceplate, and primary and secondary check vales, which are safety valves that open when the delivery device's adapter is inserted into the station outlet and which close automatically when the adapter is disengaged from the outlet. stations are designed with safety systems that prevent connection of incompatible devices. two safety systems are currently available: 1. diameter index safety system (DISS) 2. quick-connect adapters

Variable Orifice Flowmeters

there are several types of variable orifice flowmeters, floating ball, H-type float, plumb bob float, etc., the common type variable orifice flowmeter used in respiratory care is a floating ball type flowmeter called the Thorpe tube flowmeter. a. Thorpe tubes - these devices consist of a tapered, hollow tube engraved with a calibrated scale (usually in Lpm), a float (ball), and a needle valve for controlling the flow rate of gas. b. flowmeters used for neonatal and pediatric care are calibrated in mLpm Thorpe tubes come in green for oxygen and in black for air.

heliox mixtures

these 80-20% and 70-30% factors are useful in making accurate deliveries of heliox mixtures if only an oxygen flowmeter is available.

Ken says

write it in your "pocket brain" (put a note in your pocket)

A definition for Regulators

you direct access to 50psi