I. Subject: Compressed gas cylinders, regulators, and portable liquid systems. II. Objective: To provide safe and effective use, storage, and transport of therapeutic gases. II. Procedure: A. Compressed Gas Cylinders- A compressed gas cylinder contains a large volume of gas kept under high pressure in a cylinder made of steel or chrome molybdenum. Sizes of tanks are designated by letters from "A" to "H"; and the gas capacity increases as one advances the alphabet. Contents of the cylinders are identified by a label and the color (s) of the tank. Color Code- (O2) Oxygen Green Compressed Air Yellow (N2O) Nitrous Oxide Blue (CO2) Carbon Dioxide Gray Oxygen with Carbon Dioxide Green and Gray (HE) Helium and Oxygen Green and Brown (N2) Nitrogen Black It should be emphasized that color coding should be used only as a guide in identifying gases and that the primary identification for gas cylinder content is the label. Do not use a cylinder of gas which does not have a legible label attached. B. Safety Precautions- 1. Never permit oil, grease or other readily combustible substances to come in contact with cylinders, valve regulators, gauges, hoses, or fittings. 2. The cylinder should always be secured on a stand, chained, or otherwise secured to a wall or carriage. 3. Do not place cylinders where they might become part of an electric circuit. 1
4. Cylinder valves should be closed at all times except when the gas is actually being used. 5. No part of any cylinder containing a compressed gas should be subjected to a temperature above 130F. 6. Never allow cylinders to be dropped or to strike each other violently. 7. Prevent sparks or flame from any source from coming in contact with cylinders and equipment. 8. Fully open the cylinder valve when cylinder is in use. 9. Connections to piping, regulators and other appliances should always be kept tight to prevent leakage. 10. When a regulator is not attached, a cap should be kept on the cylinder head. 11. All large cylinders must be transported by use of a cylinder carriage and be secured to the cylinder carriage, whether empty or full. All transported large cylinders must have the proper cylinder cap on securely. 12. All tanks must be returned to the storeroom when empty and so labeled. 13. No cylinders are to be loaned to anyone outside the hospital. 14. Oxygen accelerates combustion. No smoking will be allow in areas in which oxygen or oxygen mixtures are in use or are being stored. 15. Cylinders used for transport should be secured on headboard, footboard, or under bed or stretcher, or in rolling stand. 16. Transfilling gas cylinders from another is prohibilted. 17. Smoking materials (cigarettes, pipes, cigars, matchs) must be removed from areas that compressed gas cylinders are stored or are in use. 18. No solid fuel burning appliances or ignition sources can be present where oxygen is stored or in use. 2
19. No non-medical appliances with hot surfacesor sparking mechanisms can be present where oxygen is stored or in use. 20. Oxygen and medical air storage rooms should have the following sign posted on the door: Medical Gases: NO Smoking or Open Flame 21. Storage rooms for other gases should have the following sign posted on the door: Positive Pressure Gases: No Smoking or Open Flame Room May Have Insufficient Oxygen Open Door and Allow Room To ventilate Before Entering 22. Gas cylinders should be used in order of their receipt. C. Regulators- Regulators are attached to the valve of a tank of compressed gas for the purpose of reducing the pressure of gas in the tank to a safe, functional, working level. Regulators are comprised of a reducing valve and a flow metering device. The amount of gas in the tank registers in pounds per square inch (PSIG) on the regulator gauge. All regulators must meet Diameter Index Safety Systems standards, or Pin Index Safety Standards, which means they will fit only the type of tank for which they are designated, i.e., oxygen regulators for oxygen tanks only; carbon dioxide regulators fit carbon dioxide only. Regulators should be labeled for the gas for which they are intended. 1. There are two (2) types of regulators for use: a. Multistage (Two or more reducing valves) b. Single stage (One reducing valve) More stages provide greater accuracy. 2. Each regulator will have a combination of pressure gauges and flow meters, 3
which may include one or more of the following: a. Pressure gauges- i. A primary "tank pressure" gauge. ii. iii. A second "adjustable working pressure" gauge (usually adjusted to 50 PSIG). Non-adjustable working pressure gauge, in which case the working pressure is preset (usually 50 PSIG). b. Flowmeter- i. Thorpe-tube- incorporates a vertical tube of gradually increasing diameter. A ball within the tube acts as a flow indicator as gas flow is turned on. Flowmeters should be labeled for the gas for which they are intended. aa) bb) Non-back pressure compensated- Needle valve is located upstream from Thorpe tube such that gas in tube is at atmospheric pressure. When resistance is posed, flow measurement is not accurate. Back pressure compensated- Needle valve is located downstream from Thorpe tube such that gas in the tube is at working pressure (usually 50 PSIG) and accuracy is not affected when resistance is met. All Thorpe tube flowmeters used within the hospital are of this type. ii. iii. Flow restrictors- use single or multiple size orifices to allow a known flow at a known working pressure. Resistance placed downstream will affect accuracy. Bourdon-gauge- uses a fixed orifice and alters the pressure gradient across it to adjust flow. Resistance placed downstream will affect accuracy. 4
D. Instruction for Operation of Tank and Regulator- 1. With valve outlet turned away from all persons, "crack" tank by opening the valve and then closing it. This procedure blows any dust in the valve into the room air instead of into the regulator. 2. Attach regulator securely. 3. Turn tank valve completely opened by making sure handle is turned counterclockwise as far as it will go, then turn back clockwise 1/4 turn. If tank is full, gauge will read approximately 1800-2200 PSIG. 4. If the regulator has two (2) pressure gauges, be sure the second is set for 50 PSIG. 5. Change tank when "tank pressure" reads below 500 PSIG for small cylinders, and 300 PSIG for large cylinders. E. To Estimate How Long the Oxygen Supply in a Tank will last: H-cylinder Cylinder pressure (psig) X 3.0 = Minutes Flow setting (LPM) E-cylinder Cylinder pressure (psig) x 0.3 = Minutes Flow setting (LPM) F. Portable Liquid Oxygen System- In addition to following the basic precautions for oxygen therapy safety, these additional guidelines should be observed: 1. Keep liquid oxygen containers in an upright position-do not lay them or roll them on their sides. Do not allow liquid oxygen containers to touch patient. 2. Keep liquid oxygen units in well-ventilated places. 3. Liquid oxygen is extremely cold (-300F). Do not touch frosted fitting or 5
piping with bare hands. When filling liquid containers, protective eye wear should be worn. 4. In the event of a malfunction, stand clear of any liquid or cold gas that might be released, open doors to ventilate the room, keep personnel and sources of ignition away from the area for at least 15 minutes, and notify service representative. 5. For specific operating and filling instructions, consult the operating instructions. 6. To calculate the duration of liquid oxygen supply: Gas supply remaining = Liquid weight (lbs.) x 860 2.51 lbs. G. Storage: Duration of supply contents = Gas supply remaining Flow rate set 1. Storage for non-flammable gases greater than 300 ft 3 but less than 3000 ft 3 shall be outdoors in an enclose or within an enclosed interior space of noncombustible or limited-combustible construction, with doors (or gates outdoors) that can be secured against unauthorized entry. 2. Storage for non-flammable gases greater than 3000 ft 3 will be constructed in compliance with NFPA 99 2012. 3. Oxidizing gases such as oxygen and nitrous oxide shall not be stored with any flammable gas, liquid, or vapor. 4. Oxidizing gases shall be separated from combustible materials by one of the following: a) Minimum distance of 20 feet b) Minimum distance of 5 feet if the entire storage location is protected by an automatic sprinkler system. 6
c) Enclosed cabinet of noncombustible construction having a minimum fire protection rating of ½ hour. 5. Smoking, open flames electrical heating elements, and other sources of ignition shall be prohibited within 20 feet of outside storage locations. 6. Full cylinders shall be segregated from empty cylinders. The location and/or storage cart will be clearly marked as to full or empty. 7. Individual cylinder storage associated with patient care areas, not to exceed 22,500 ft 3 of floor area, shall not be required to be stored in enclosures. a. A maximum of twelve (12) E-cylinders may be stored on a unit and are considered in use. Stored cylinders must be segregated into full and partially full/empty. 8. All cylinders with 1800 PSIG or greater should be considered full. Cylinders with less than 1800 PSIG should be considered partially full/empty. 9. Make sure all medical gas cylinders are always secured. a. When small-size cylinders are in use, they shall be attached to a cylinder stand or to medical equipment designed to received and hold compressed gas cylinders. 10. Individual small-size cylinders available for immediate use in patient care areas shall not be considered in storage. 11. Oxygen-delivery equipment designed to rest on the floor shall be equipped with a base designed to render the entire assembly stable during transport, and use. 12. Humidification or reservoir jars containing liquid to be dispensed into a gas stream shall be made of transparent or translucent material, shall be impervious to a contained solution and medications, and shall allow observation of the liquid level and consistency. 13. Humidifiers and nebulizers shall be equipped with provisions for 7
overpressure relief or alarm if flow becomes obstructed. 14. Humidifiers and nebulizers shall be incapable of tipping or shall be mounted so that any tipping or alteration from the vertical shall not interfere with function or accuracy. 8