2-1 Unit 2 Gas Regulating Devices GOAL On completion of this unit, the student should have an understanding of the principles of operation, correct techniques of use and safety systems of pressure regulators and flowmeters COMPETENCIES 1. Identify components of preset and adjustable pressure regulators. 2. Examine and describe various pressure regulators. 3. Demonstrate proper technique of attaching pressure regulators to available gas cylinders. 4. Identify components of Thorpe tube and Bourdon flowmeters. 5. Examine and describe various flowmeters. 6. Attach a flowmeter to both types of pressure regulators. 7. Verify contents of cylinder (psi). 8. Determine the accuracy of flowmeters. 9. Complete applicable procedures in the clinical simulation lab. EQUIPMENT 1. pressure regulators a. PISS b. ASSS (TISS) c. preset d. adjustable e. single stage f. multi-stage 2. various medical gas cylinders 3. air and oxygen flowmeters a. Thorpe tube (2 types) b. Bourdon 4. flowmeter nipple 5. respirometer 6. 3/8 inch oxygen connecting tubing
2-2 EXERCISE A - REGULATOR COMPONENTS 1. Identify the following components on a preset pressure regulator and label Fig. 1. a. gas inlet (ASSS) b. pressure guage c. gas outlet (DISS) d. flowmeter e. body f. pressure relief valve(s) Fig. 1 2. Identify the following components on an adjustable pressure regulator and label Fig. 2. a. gas inlet (ASSS) b. pressure guage c. gas outlet (DISS) d. flowmeter e. body f. adjusting screw g. pressure relief valve(s)
2-3 Fig. 2 EXERCISE B - REGULATOR EXAMINATION/DESCRIPTION 1. Compare a single stage regulator to a multistage regulator and record your observations of differences and similarities. 2. Compare a preset regulator to an adjustable regulator and record your observations of differences and similarities.
2-4 3. Examine the different regulators available and complete the following table. Number of Cylinder Flowmeter PISS Regulator Pressure Connection Connection Position Color Type Relief Valves Type Type or ASSS Coding? Labeling? EXERCISE C - FLOWMETER EXAMINATION/DESCRIPTION 1. Examine a Thorpe tube flowmeter and compare it to Fig. 3. Trace the gas flow and label the following components on the diagram. a. gas inlet (DISS) d. float b. gas outlet (DISS) e. gas coding c. needle valve f. flow tube Fig. 3a Fig. 3b
2-5 2. Examine a Bourdon gauge flowmeter and compare it to Fig. 4. Trace the gas flow and label the following components on the diagram. a. gas inlet (DISS) d. gear mechanism b. gas outlet (fixed orifice) e. gas coding c. coiled tube f. indicator needle Fig. 4 EXERCISE D - PRESSURE REGULATOR ATTACHMENT 1. Attach a regulator to a K cylinder. a. secure cylinder to stand or hand truck b. crack cylinder by pointing outlet away from others and slowly opening and quickly closing the valve c. attach the regulator to the valve outlet by inserting the American Standard Connection into and around the valve outlet and tighten d. make sure all flow controls are OFF prior to opening the cylinder valve e. make sure the regulator is pointing away from others prior to opening the cylinder valve f. slowly open the cylinder valve while watching the pressure manometer g. check regulator/cylinder attachment for leaks h. turn on flowmeter slowly, checking for leaks i. close cylinder valve, allowing pressure to bleed off through flowmeter j. turn off flowmeter
2-6 2. Attach a regulator to an E cylinder. a. secure cylinder to stand or hand truck b. crack cylinder by pointing outlet away from others and slowly opening and quickly closing the valve c. attach the regulator to the valve outlet by inserting the PISS pins into valve outlet and tighten d. make sure all flow controls are OFF prior to opening the cylinder valve e. make sure the regulator is pointing away from others prior to opening the cylinder valve f. slowly open the cylinder valve while watching the pressure manometer g. check regulator/cylinder attachment for leaks h. turn on flowmeter slowly, checking for leaks i. close cylinder valve, allowing pressure to bleed off through flowmeter j. turn off flowmeter 3. Complete the Checking and Changing E Cylinders procedure in the clinical simulation lab. EXERCISE E - FLOWMETER ACCURACY 1. Attach the selected flowmeter to a gas source. 2. Attach a flowmeter nipple to the flowmeter outlet. 3. Attach a 3/8 in. connecting tubing to the nipple. 4. Attach the tubing to a spirometer. 5. Measure observed flowrate and compare it to predicted flowrate. Record your findings on the table. 6. Repeat each procedure with the tubing kinked. Make sure flow stays above zero. Record your findings on the table. 7. Explain your findings and their clinical importance. Thorpe tube flowmeter: Observed flowrate with kinked tube Measured spirometer Spirometer flow 5 10 Thorpe tube flowmeter: Observed flowrate with kinked tube Measured spirometer Spirometer flow 5 10
2-7 Bourdon flowmeter: Observed flowrate with kinked tube Measured spirometer Spirometer flow 5 10 EXERCISE F - DISS AND QUICK CONNECT FLOWMETER CONNECTIONS 1. Examine the various types of DISS and quick connect flowmeters. 2. Briefly describe the method of connection for each flowmeter type.
2-8 WORKSHEET 1. Explain how predicted flow and actual flow would differ in the following devices if flow were obstructed. a. compensated Thorpe tube b. uncompensated Thorpe tube c. Bourdon gauge 2. During patient transport, the O2 cylinder and flowmeter must be placed horizontally on the bed. Which flowmeter would be indicated in this situation? Why? 3. List three methods of determining if a flowmeter is compensated. 4. Is a DISS inlet or outlet ever directly connected to a gas cylinder outlet? If yes, which sizes? If no, why not? 5. Explain how a two stage preset pressure regulator establishes a pressure of 50 psig.