02 cylinder

Components of Oxygen Delivery Systems

Bourdon Gauge

  • A pressure gauge that measures the amount of oxygen delivered by a flow system. It operates by measuring pressure within the system, which is then converted to a flow reading through a pressure-reducing regulator and a fixed orifice. This design makes it gravity-independent.

  • Connected to a regulator, the flow should be set to 8 liters per minute (lpm).

  • Step 1: Connect a bourdon gauge regulator and turn the flow up to 8 lpm.

  • Step 2: Turn the tank on its side; observe that the flow remains steady, confirming system integrity, as its function is not affected by gravity.

  • Step 3: Occlude the oxygen flow; the gauge indicates pressure, not actual flow being delivered to the patient (it reflects pressure build-up but no actual gas movement through the outlet).

Thorpe Tube

  • A flow meter that accurately measures gas flow using a float within a tapered tube. It utilizes a bobbin or ball float that rises in a tapered tube due to the force of the gas flow against gravity. This makes it gravity-dependent, requiring an upright position for accurate readings.

  • Step 4: Connect a Thorpe tube flow-meter and set the flow to 8 lpm.

  • Step 5: When the tank is turned on its side, the float ball goes to the top, indicating an inaccurate reading due to the effect of gravity on the float.

  • Step 6: Occlude the oxygen flow; the Thorpe tube's float drops to zero, accurately indicating that no flow is being delivered.

  • Step 7: The Thorpe tube displays true flow and is preferred for accurate measurements when oriented upright.

Oxygen Flow Ranges

  • The normal liter flow range for a nasal cannula (NC) is 1−61-6 lpm, providing a fraction of inspired oxygen (FiO2) of approximately 24%−44%24\%-44\%.

  • A simple mask typically delivers oxygen at 6−106-10 lpm, yielding an FiO2 of about 35%−50%35\%-50\%.

  • A non-rebreather mask delivers oxygen at 10−1510-15 lpm, achieving the highest possible FiO2 through a mask, typically 60%−90%60\%-90\%, by utilizing a reservoir bag and one-way valves.

Room Air and Oxygen Delivery

Composition of Room Air

  • Room air contains approximately 21%21\% oxygen.

Factors Affecting FiO2

  • For every one liter per minute (lpm) of oxygen flow increase (via nasal cannula), the fraction of inspired oxygen (FiO2) increases by approximately 3%3\% from room air (21\%$). This approximation is most accurate for flows between 1-6lpm.</p></li></ul><h4id="2b2057ac−8b79−475b−bf1f−974bcb4b2797"data−toc−id="2b2057ac−8b79−475b−bf1f−974bcb4b2797"collapsed="false"seolevelmigrated="true">Flow−MeterTypesandCylinderOrientation</h4><h5id="2a599bab−6a57−46c3−8180−4557f233048d"data−toc−id="2a599bab−6a57−46c3−8180−4557f233048d"collapsed="false"seolevelmigrated="true">PreferredFlow−MeterTypes</h5><ul><li><p>Ifacylinderneedstobeplacedonitsside,aBourdonflow−metertypeispreferredasitfunctionsindependentlyofgravity.</p></li></ul><h4id="90af61a0−18a5−4c4c−9b3d−f20118544620"data−toc−id="90af61a0−18a5−4c4c−9b3d−f20118544620"collapsed="false"seolevelmigrated="true">SafetyReliefValves</h4><h5id="33adc0a6−55b7−4b2c−938b−edcaf9a34e46"data−toc−id="33adc0a6−55b7−4b2c−938b−edcaf9a34e46"collapsed="false"seolevelmigrated="true">ETankSafetyReliefValve</h5><ul><li><p>ThesafetyreliefvalveforanEtankisknownasthePressureIndicatorSafetySystem(PISS).</p></li></ul><h5id="6c0ef1c9−4956−44fb−bbfe−d86cea479655"data−toc−id="6c0ef1c9−4956−44fb−bbfe−d86cea479655"collapsed="false"seolevelmigrated="true">HTankSafetyReliefValve</h5><ul><li><p>ThesafetyreliefvalveforanHtankisknownastheAmericanStandardSafetySystem(ASSS).</p></li></ul><h4id="d673079c−5593−4b19−b9fd−d48f0ae57aa8"data−toc−id="d673079c−5593−4b19−b9fd−d48f0ae57aa8"collapsed="false"seolevelmigrated="true">PracticeDurationofGasandLiquidDeliverySystems</h4><ul><li><p>Understandinghowlongdifferentgassourceswilllastatvariousflowratesiscrucialforinterventionalpreparation.</p></li></ul><h5id="33aba832−2279−498b−801d−67aaeef75fd6"data−toc−id="33aba832−2279−498b−801d−67aaeef75fd6"collapsed="false"seolevelmigrated="true">ECylinderDuration</h5><ul><li><p>AnEcylinderwithlpm.</p></li></ul><h4 id="2b2057ac-8b79-475b-bf1f-974bcb4b2797" data-toc-id="2b2057ac-8b79-475b-bf1f-974bcb4b2797" collapsed="false" seolevelmigrated="true">Flow-Meter Types and Cylinder Orientation</h4><h5 id="2a599bab-6a57-46c3-8180-4557f233048d" data-toc-id="2a599bab-6a57-46c3-8180-4557f233048d" collapsed="false" seolevelmigrated="true">Preferred Flow-Meter Types</h5><ul><li><p>If a cylinder needs to be placed on its side, a Bourdon flow-meter type is preferred as it functions independently of gravity.</p></li></ul><h4 id="90af61a0-18a5-4c4c-9b3d-f20118544620" data-toc-id="90af61a0-18a5-4c4c-9b3d-f20118544620" collapsed="false" seolevelmigrated="true">Safety Relief Valves</h4><h5 id="33adc0a6-55b7-4b2c-938b-edcaf9a34e46" data-toc-id="33adc0a6-55b7-4b2c-938b-edcaf9a34e46" collapsed="false" seolevelmigrated="true">E Tank Safety Relief Valve</h5><ul><li><p>The safety relief valve for an E tank is known as the Pressure Indicator Safety System (PISS).</p></li></ul><h5 id="6c0ef1c9-4956-44fb-bbfe-d86cea479655" data-toc-id="6c0ef1c9-4956-44fb-bbfe-d86cea479655" collapsed="false" seolevelmigrated="true">H Tank Safety Relief Valve</h5><ul><li><p>The safety relief valve for an H tank is known as the American Standard Safety System (ASSS).</p></li></ul><h4 id="d673079c-5593-4b19-b9fd-d48f0ae57aa8" data-toc-id="d673079c-5593-4b19-b9fd-d48f0ae57aa8" collapsed="false" seolevelmigrated="true">Practice Duration of Gas and Liquid Delivery Systems</h4><ul><li><p>Understanding how long different gas sources will last at various flow rates is crucial for interventional preparation.</p></li></ul><h5 id="33aba832-2279-498b-801d-67aaeef75fd6" data-toc-id="33aba832-2279-498b-801d-67aaeef75fd6" collapsed="false" seolevelmigrated="true">E Cylinder Duration</h5><ul><li><p>An E cylinder with800psiataflowofpsi at a flow of3lpmnasalcannulawilllast:</p><ul><li><p>Thegeneralformulaforcylinderdurationis:Duration(minutes)=(CylinderPSIxCylinderFactor)/FlowRate(L/min).</p></li><li><p>ThecylinderfactorforanEcylinderisapproximatelylpm nasal cannula will last:</p><ul><li><p>The general formula for cylinder duration is: Duration (minutes) = (Cylinder PSI x Cylinder Factor) / Flow Rate (L/min).</p></li><li><p>The cylinder factor for an E cylinder is approximately0.28L/PSI.</p></li><li><p>So,Duration(minutes)=(L/PSI.</p></li><li><p>So, Duration (minutes) = (800PSIxPSI x0.28L/PSI)/L/PSI) /3L/minL/min= 224 / 3 \approx 74.67minutes,orapproximatelyminutes, or approximately1hourandhour and15minutes.</p></li><li><p>Tocalculatedurationinhours:Duration(hours)=(CylinderPSIxminutes.</p></li><li><p>To calculate duration in hours: Duration (hours) = (Cylinder PSI x0.28)/(FlowRatex) / (Flow Rate x60).</p></li></ul></li></ul><h5id="6ac4f0a9−e454−460d−a726−004a821c2f17"data−toc−id="6ac4f0a9−e454−460d−a726−004a821c2f17"collapsed="false"seolevelmigrated="true">LiquidOxygenTankDuration</h5><ul><li><p>Aliquidoxygentankwith).</p></li></ul></li></ul><h5 id="6ac4f0a9-e454-460d-a726-004a821c2f17" data-toc-id="6ac4f0a9-e454-460d-a726-004a821c2f17" collapsed="false" seolevelmigrated="true">Liquid Oxygen Tank Duration</h5><ul><li><p>A liquid oxygen tank with1.5lbs.ofO2ataflowoflbs. of O2 at a flow of3lpmnasalcannulawillprovidegasforaspecificdurationbasedontheliquidoxygenequation:</p><ul><li><p>Anapproximateconversionfactorforliquidoxygenislpm nasal cannula will provide gas for a specific duration based on the liquid oxygen equation:</p><ul><li><p>An approximate conversion factor for liquid oxygen is1lbofliquidO2=lb of liquid O2 =344LofgaseousO2.</p></li><li><p>Duration(minutes)=(WeightofO2(lbs)xL of gaseous O2.</p></li><li><p>Duration (minutes) = (Weight of O2 (lbs) x344L/lb)/FlowRate(L/min).</p></li><li><p>So,Duration(minutes)=(L/lb) / Flow Rate (L/min).</p></li><li><p>So, Duration (minutes) = (1.5lbsxlbs x344L/lb)/L/lb) /3L/minL/min= 516 / 3 = 172minutes,orminutes, or2hoursandhours and52minutes.</p></li><li><p>Tocalculatedurationinhours:Duration(hours)=(WeightofO2(lbs)xminutes.</p></li><li><p>To calculate duration in hours: Duration (hours) = (Weight of O2 (lbs) x344)/(FlowRatex) / (Flow Rate x60).</p></li></ul></li></ul><h5id="e4c5c0cd−1037−431a−8ab4−e165a7e7ddc7"data−toc−id="e4c5c0cd−1037−431a−8ab4−e165a7e7ddc7"collapsed="false"seolevelmigrated="true">HCylinderDuration</h5><ul><li><p>AnHcylinderwithaPSIof).</p></li></ul></li></ul><h5 id="e4c5c0cd-1037-431a-8ab4-e165a7e7ddc7" data-toc-id="e4c5c0cd-1037-431a-8ab4-e165a7e7ddc7" collapsed="false" seolevelmigrated="true">H Cylinder Duration</h5><ul><li><p>An H cylinder with a PSI of1500ataflowofat a flow of15lpmwillhaveacalculateddurationbasedontheappropriateformulaforthetanksizeandoperatingpressure:</p><ul><li><p>ThecylinderfactorforanHcylinderisapproximatelylpm will have a calculated duration based on the appropriate formula for the tank size and operating pressure:</p><ul><li><p>The cylinder factor for an H cylinder is approximately3.14L/PSI.</p></li><li><p>Duration(minutes)=(CylinderPSIxL/PSI.</p></li><li><p>Duration (minutes) = (Cylinder PSI x3.14L/PSI)/FlowRate(L/min).</p></li><li><p>So,Duration(minutes)=(L/PSI) / Flow Rate (L/min).</p></li><li><p>So, Duration (minutes) = (1500PSIxPSI x3.14L/PSI)/L/PSI) /15L/minL/min= 4710 / 15 = 314minutes,orminutes, or5hoursandhours and14minutes.</p></li><li><p>Tocalculatedurationinhours:Duration(hours)=(CylinderPSIxminutes.</p></li><li><p>To calculate duration in hours: Duration (hours) = (Cylinder PSI x3.14)/(FlowRatex) / (Flow Rate x60).</p></li></ul></li></ul><h5id="0427c498−f43a−42a7−9fa0−bdb5b5cf2ae3"data−toc−id="0427c498−f43a−42a7−9fa0−bdb5b5cf2ae3"collapsed="false"seolevelmigrated="true">3lbLiquidOxygenCylinderDuration</h5><ul><li><p>A).</p></li></ul></li></ul><h5 id="0427c498-f43a-42a7-9fa0-bdb5b5cf2ae3" data-toc-id="0427c498-f43a-42a7-9fa0-bdb5b5cf2ae3" collapsed="false" seolevelmigrated="true">3 lb Liquid Oxygen Cylinder Duration</h5><ul><li><p>A3lbliquidoxygencylinderataflowoflb liquid oxygen cylinder at a flow of12lpmwillhavealimitedoperationaltimebasedonsimilarcalculationsreferencingliquidweightandflowrates:</p><ul><li><p>Usingtheconversionfactoroflpm will have a limited operational time based on similar calculations referencing liquid weight and flow rates:</p><ul><li><p>Using the conversion factor of1lbliquidO2=lb liquid O2 =344LgaseousO2.</p></li><li><p>Duration(minutes)=(WeightofO2(lbs)xL gaseous O2.</p></li><li><p>Duration (minutes) = (Weight of O2 (lbs) x344L/lb)/FlowRate(L/min).</p></li><li><p>So,Duration(minutes)=(L/lb) / Flow Rate (L/min).</p></li><li><p>So, Duration (minutes) = (3lbsxlbs x344L/lb)/L/lb) /12L/minL/min= 1032 / 12 = 86minutes,orminutes, or1hourandhour and26minutes.</p></li><li><p>Tocalculatedurationinhours:Duration(hours)=(WeightofO2(lbs)xminutes.</p></li><li><p>To calculate duration in hours: Duration (hours) = (Weight of O2 (lbs) x344)/(FlowRatex) / (Flow Rate x60$$).