Presentation on theme: "Supply Of Medical Gases"— Presentation transcript:
1Supply Of Medical Gases Tutor:Dr. Syed Sajjad NaqviPrepared By:Dr. Umar J. AlviDr. Syed Ghufran Arshad.
2Introduction Supply of Medical Gases: Medical gases commonly used: From:Cylinders (Manifold)PIPED gas systemMedical gases commonly used:OxygenNitrous oxideAirNitrogenCarbon Dioxide
3Cylinders Components: A gas cylinder or tank is a pressure vessel used to store gases at high pressure. Gases stored this way are called bottled gases.Components:Made of Molybdenum steel in which gases and vapours are stored under pressure, e.g kPa for oxygen and 4400 kPa for Nitrous oxide.Shape & colour of plastic disc around the neck of cylinder indicates the year of last examination.
4Medical Gas Cylinder D AF E F G J Cylinder Size Approx dimension(mm) Approx Weight Empty (kg)3.811.46.61330.668.7Valve TypePin-IndexBullnoseGaseous Litres0.34 (340)1.36 (1360)0.68 (680)3.4 (3400)10.6 (10600)
5Components They are manufactured in different sizes (A to J). Size E cylinders are used on the anaesthetic machine.Oxygen cylinders contain gas.Nitrous oxide cylinders contain a mixture of liquid and vapour. 75% liquid N2OLight weight for homes & Transportation made of aluminium alloy.
11Labelling Normal cylinder contents (Liters) Maximum cylinder pressure (Bars)Shelf life and expiry dateDirections for UseStorage and handling precautions
12StoragePurpose built, dry, well-ventilated and fire proof room, preferably inside and not subjected to extremes of heat.Not be stored near flammablesNot be exposed to dampness, corrosive chemicals or fumes. Leads to corrosion of cylinders and valves
13StorageTo avoid accidents, full cylinders should be stored separately from empty onesF, G and J size cylinders are stored upright to avoid damage to the valves.C, D and E size cylinders can be stored horizontally on shelves.Overpressurized cylinders are hazardous and should be reported to manufacturer.
14Safety FeaturesThe Gases and vapours should be free of water vapours when stored in cylinders.Water vapour freezes and blocks the exit port when the temperature of the cylinder decreases on the opening.
15Pin-IndexThe outlet valve uses the pin-index system to make it almost impossible to connect a cylinder to the wrong yoke.
16The identifying code consists of a specific combination of two holes in the face of the valve into which connecting pins for a particular type of gas must fit in perfect alignment. For example, the index hole position for a cylinder of oxygen is 2-5, for nitrous oxide it is 3-5, and so on.
17Colour CodingCylinders are colour coded to reduce accidental use of the wrong gas or vapour.
18Body Colour Shoulder Colour Oxygen Black 13700 Nitrous oxide Blue 4400 Pressure, kPa (room T)OxygenBlackWhite13700Nitrous oxideBlue4400Carbon dioxideGrey5000AirWhite/ Black quartersEntonoxWhite/ Blue quartersOxygen/ heliumWhite/ Brown quarters
19Cylinders should be checked regularly while in use to ensure that they have sufficient contents and that leaks do not occur
20Cylinder Valves Cylinder Valves seal the cylinder contents. Introdcuction:Cylinder Valves seal the cylinder contents.The chemical formula of the particular gas is engraved on the valve.
21Cylinder Valves They are mounted on the neck of cylinder. They act as an on/off device for the discharge of cylinder contents.A pin-index system prevents cylinder identification errors.
22Cylinder ValvesA Bodock sealing washer must be placed between the valve and the yoke of the anaesthetic machine.A newly designed valve allows keyless manual turning on and off.
23Piped gas system Piped gas supply ( piped Medical Gas and Vacuum PMGV) Introduction:Piped gas supply ( piped Medical Gas and Vacuum PMGV)PMGV system delivers gases from central supply points to different sites in a hospital at a pressure of about 400 kPa.
24Piped gas systemSpecial outlet valves supply the various needs throughout the hospital.Oxygen, nitrous oxide, Entonox, compressed air and medical vacuum are commonly supplied through the pipeline system.
25Components Central supply points Cylinder banks.Liquid oxygen storage tank.Pipework made of special high quality copper with bacteriostatic properties.Outlets identified by gas colour coding, gas name and shape.Matching quick connect/ disconnect probes
26Piped gas supplyNetwork of pipelines throughout a hospital from central supplyOutlets are colour- and shape-codedFlexible and colour-coded pipelines runs from the anaesthetic machine to outlets
27Safety features Reserve bank of cylinders Low pressure alarms Single hose test, cross-connectionTug test, miss-connectionRegular PGMV installation, repair and modification
28Sources of Gas supply Cylinder Manifold Liquid oxygen storage tank Oxygen concentrator
29Cylinder ManifoldIntroduction:Manifolds are used to supply, Oxygen, Nitrous oxide and Entonox.
31ComponentsLarge cylinders (e.g. Size J) are divided into 2 groups, primary & secondary.The 2 groups alternate in supplying the pipelines.All cylinders in each group are connected through non return valves to a common pipe.In turn connected to pipeline.
32Mechanism of actionIn either group all cylinder valves are open to allow simultaneously empting.The supply is automatically changed to the secondary group when the primary group is nearly empty.This changeover is achieved by a pressure sensitive device.Alarm is activated to alert staff
33Safety FeaturesManifold should be housed in a well – ventilated room built of fire proof material away from the main hospital building.Manifold room should not be used as a general cylinder store.Empty cylinders should be immediately removed from the manifold room.
34Liquid Oxygen Vacuum-insulated evaporator. Components: Thermally insulated vessel where vacuum is used as insulationPressure regulator allows gas to enter pipelines & maintain pressure of 400 kPa.Safety valve opens at 1700 kPaControl valve opens for excessive demand.
35Outer carbon steel shell and an inner stainless steel shell, with a vacuum insulation in between and kept cold (between -160°C to - 180°C as the critical temperature of oxygen is - 118°C).
37ENTONOXCompressed gas mixture of 50% oxygen & 50% nitrous oxide by volume.Used in casualty & labour wards for analgesia.A two-stage pressure demand regulator is attached to the entonox cylinder.
38ENTONOXEntonox is the registered trademark of BOC Healthcare. Entonox, referred to as gas and air, is an analgesic used to ease pain during labour, trauma and minor surgical procedures.Entonox is administered by inhalation from a cylinder at a pressure of 137 bar (in the UK) or from a pipeline supply.
39ENTONOXIts analgesic effect is strong (equivalent to 5 to 10 mg of morphine) and characterised by rapid onset and offsetEntonox is self administered.Self-administration of Entonox remains safe because if enough is inhaled to start to induce anaesthesia, the patient becomes unable to hold the valve, and so will drop it and soon exhale the residual gas.The 50% oxygen in Entonox ensures the patient will have sufficient oxygen in their system for a short period of apnoea to be safe.
40Safety FeaturesLiquefaction & separation of contents should be prevented.Prolonged use of entonox should be avoided, due to the effect on bone marrow in critically ill patient.Adequate scavenging should be provided to protect hospital staff.
41Compressed AirMedical air is supplied in hospitals for clinical uses or to drive power tools.400 kPa700 kPaCan be supplied by cylinder manifolds or by compressor