Training. tm PA90 Series - Lung Demand Valve

Transcription

1 D Training Dräger tm12842 PA90 Series - Lung Demand Valve

2 Index Section 1 Instructions for Use Section 2 Introduction and Safety Warnings Section 3 Product Description Section 4 Operating Principle Section 5 Servicing Instructions Section 6 Test Procedures Section 7 Fault Location Section 8 Spare Parts List and Tool List

3

4 1:0 Section 1 Instructions for Use

5 1:1 Positive Pressure Lung Demand Valve Type A Series Positive Pressure Lung Demand Valve Type AE Series Normal Demand Lung Demand Valve Type N Series

6 2:0 Section 2 Introduction and Safety Warnings

7 2:1 Introduction The PA90 Series of Lung Demand Valves are approved for use with approved Dräger Compressed Air Breathing Equipment (C.A.B.E.) and Facepieces. Refer to Illustration The combination of Lung Demand Valve, C.A.B.E. and Facepiece provides the wearer of the equipment with respiratory protection when working in or escaping from a contaminated or oxygen deficient life-threatening environment. Safety Warnings! Explain - Instructions for Use, supplied with the equipment must be adhered to.! Maintain - the respiratory protection equipment must be maintained as outlined in the Dräger Limited service schedules and maintenance instructions. Contact Dräger Limited, Blyth for details of Service Contracts and Service Training Courses.! Train potential wearers in how to wear and use equipment and to understand its limitations. Contact Dräger Limited, Blyth for details of Wearer Training Courses.

8 2:2 Positive Pressure - Type A Illustrated 1241

9 2:3

10 3:0 Section 3 Product Description

11 3:1 Product Description The variants of the PA90 Series Lung Demand Valve are as follows:! Type A - Positive Pressure with Push-In connector to facepiece.! Type AE - Positive Pressure with M45 Screw-In connector to facepiece.! Type N - Normal Demand with M40 (Rd40) Screw-In connector to facepiece. The high performance Lung Demand Valves incorporate a precision factory set and sealed balanced piston unit that has unlimited service life. The Dräger Warranty and Guarantee is void should any attempt be made by customers to make adjustment to the balanced piston unit. Detachable variants of the lung demand valves have a medium pressure hose with a quick release male coupling to connect the demand valve to the female coupling of the medium pressure hose from the pressure reducer of the appropriate C.A.B.E. Fixed variants of the lung demand valves incorporate a medium pressure hose having an end fitting design for connecting directly to the medium pressure outlet port of the pressure reducer of the appropriate C.A.B.E. The housing of the lung demand valves are manufactured from a moulded composite glass filled material that provides a high degree of strength and durability. Positive pressure types have a manually operated re-set lever to switch OFF the positive pressure function - this must be pressed before opening the valve of compressed air cylinder. First breath inhalation by the wearer will switch ON the positive pressure. All variants include a supplementary air supply facility that is made active by pressing the centre of the protective rubber cover at the front of the lung demand valve. Lung demand valves fitted to short duration C.A.B.E. and escape units will not normally include a supplementary air supply facility.

12 4:0 Section 4 Operating Principle

13 4:1 Contents Section Description 4.1 Positive Pressure Lung Demand Valves A and AE 4.2 Normal Demand Lung Demand Valves - N

14 4:2 4.1 Positive Pressure Lung Demand Valves - A and AE Refer to Figure 1. Before turning On the high pressure air supply the positive pressure mechanism must be switched Off by pressing the re-set lever on the side of the lung demand valve to lift and lock the main pivot lever and diaphragm. On opening the cylinder valve, medium pressure air flows from the reducer through a hose and swivel banjo then into main bore of balanced piston block. Increasing air pressure moves the balanced piston axially, forcing the piston cone against the O-Ring seal located in the block - sealing Off the airflow from outlet of lung demand valve. Refer to Figure 2. When the wearer begins to inhale this creates a negative pressure inside the facepiece and lung demand valve. Due to the negative pressure the ambient air pressure acts against the diaphragm. As the diaphragm deflects it then presses against the main hinged lever of the balanced piston unit resulting in the release of the positive pressure Off mechanism. Increasing deflection of the diaphragm, during inhalation, pivots the balanced piston lever forcing it against the end cap of the piston - moving the piston axially and lifting the piston cone from its seating and releasing air from the lung demand valve into wearer s facepiece. Two extension springs attached to the balanced piston block and the main lever act on the balanced piston, lifting the sealing cone and maintaining a positive pressure (above ambient) inside the facepiece. When the wearer stops inhaling then begins to exhale, the diaphragm, pivot lever and sealing cone retract. The cycle repeats as the wearer begins to inhale.

15 4:3 Balanced Piston Closed Medium Pressure (M.P.) Fig Balanced Piston Open M.P. Flow to Facepiece Fig

16 4:4 4.2 Normal Demand Lung Demand Valves - N Refer to Figure 3 On opening cylinder valve, medium pressure air flows from the reducer, through a hose and swivel banjo then into main bore of balanced piston block. Increasing air pressure moves the balanced piston axially, forcing the piston cone against the O-Ring seal located in the block - sealing Off the airflow from outlet of lung demand valve. Refer to Figure 4 When the wearer begins to inhale this creates a negative pressure inside the facepiece and lung demand valve. Due to the negative pressure the ambient air pressure acts against the diaphragm then the main hinged lever of the balanced piston unit. Increasing deflection of the diaphragm, during inhalation, pivots the balanced piston lever forcing it against the end cap of the piston - moving the piston axially and lifting the piston cone from its seating and releasing air from the lung demand valve into wearer s facepiece. When the wearer stops inhaling then begins to exhale, the diaphragm, pivot lever and sealing cone retract. The cycle repeats as the wearer begins to inhale.

17 4:5 Balanced Piston Closed Medium Pressure (M.P.) Fig Balanced Piston Open M.P. Flow to Facepiece Fig

18 5:0 Section 5 Servicing Instructions

19 5:1 5:1 Contents Section Description 5.1 Contents 5.2 Service and Test Intervals 5.3 Cleaning, Disinfecting and Drying Important Information Cleaning and Disinfecting 5.4 Replacing Diaphragm 5.5 Replacing Medium Pressure Hoses Removing MP Hose (Elbow Connector) Removing MP (Straight Connector) Assembly of MP Hose (Elbow Connector) to Demand Valve Assembly of MP Hose (Straight Connector) to Demand Valve 5.6 The Balanced Piston Unit Removing Balanced Piston Unit Replacing/Refitting Return Spring Positive Pressure Replacing Springs of Balanced Piston Units Positive Pressure Assembly of Balanced Piston Unit to Demand Valve

20 5:2 5.2 Service and Test Intervals Carry out Inspection, Service and Testing of equipment according to this table. Record all necessary data in the Log Book for the equipment. These instructions apply also to non-used in storage equipment. Important Note: This table is intended as a general guide. Reference must also be made to the Inspection, Service and Test Intervals specified in the appropriate section of the relevant C.A.B.E. Training manual. Complete Equipment Description After Use C lean and Disinfect " Every Month V isual Inspection " # Every Year Every 6 Years Demand Valve Pressure Reducer Cylinder Cylinder Valve Functional and Leak Testing as defined in Instructions for Use Flow and Static Tests as per Manufacturers Instructions C lean and Disinfect as necessary " $ " # M edium Pressure Check " R eplace Sintered Filter " R eplace H.P. Connector O-Ring " Basic Overhaul (Repair Exchange Scheme) C harge to Correct Pressure " Charged Pressure Check. Check Test Date Stamped on Cylinder Re-Certification - Cylinder Pressure Test (According to National Standards) Overhaul as necessary, or at time of Cylinder Re-Certification "# " " " Dräger Recommendation - UK. # COSHH $ Type A - Push-In demand valve apply grease ( ) around connector O-ring.

21 5:3 5.3 Cleaning, Disinfecting and Drying Important Information Dräger recommend that contaminated and dirty components or assemblies are carefully cleaned and disinfected then thoroughly dried after use, or as and when considered necessary by the user. To ensure correct operational condition of the equipment use the cleaning and disinfecting solutions recommended by Dräger. The use of any other product will invalidate the Dräger warranty and guarantee. When using baths to contain cleaning and disinfecting solutions the immersed components and assemblies must only be agitated manually. It is important to note that Dräger Do Not recommend the use of any form of mechanical, electrical or ultrasonic agitation of this product. If the user decides however to use ultrasonic cleaning baths then it is important that the instructions supplied by the manufacturer of the bath are strictly followed. Refer to Important Notes. Important Notes: 1.The diaphragm of the lung demand valves must not be cleaned using ultrasonic techniques, as this will have a detrimental affect on the centrebonded area of the diaphragm. Clean and disinfect the diaphragm manually. 2.If Ultrasonic cleaning is to be used on the lung demand valve (diaphragm must be removed) this will eventually remove lubricant from the critical moving parts. Duration in the bath combined with the ultrasonic energy of the machine will affect the time for this to occur. Following cleaning, disinfecting and drying carry out functional tests. Re-lubricate moving parts as required. 3.Immersing the lung demand valve and manual agitation will also eventually remove lubricants although of course this will occur over a much longer period. Following cleaning, disinfecting and drying it is recommended that functional tests be carried out. Re-lubricate moving parts as required. Safety Note: When using cleaning and disinfecting agents refer to the relevant manufacturers usage instructions. It is important that attention be paid to concentration and reaction times. Do Not use organic solvents such as Acetone, Alcohol, White Spirit, Trichloroethylene or similar. Dräger recommends: 1. Cleaning: Safety Wash 1 Litre Dispenser Litre Refill Litre Dispenser Litre Refill Sekusept 4 2 litres

22 5:4 Do Not exceed a temperature of 30 degrees Celsius. Note: Rinse off cleaning solution in clean water before disinfecting. 2. Disinfecting: Wipex Cloths (Pack of 50) Incidur 6 litre container Incidur - 30 litre container Do Not exceed a temperature of 30 degrees Celsius. Note: Rinse off disinfecting solution in clean water before drying. 3. Rinsing and Drying Remove cleaning and disinfecting solutions by rinsing in clean running water, followed by drying. Rinsing - Do Not exceed a temperature of 30 degrees Celsius. Drying - Do Not exceed a temperature of 60 degrees Celsius Cleaning and Disinfecting When the user considers it necessary to internally clean and disinfect the lung demand valve then these instructions should be followed: Note: A Detach demand valves (fitted with male coupling) from female coupling of medium pressure hose of the C.A.B.E. Note: B If necessary, demand valves attached directly to the reducer should be removed at the hose connection to the reducer. For details of removal refer to the appropriate section of the relevant C.A.B.E. Training Manual. Tools required: Plate Spanner R If required, detach the demand valve from the equipment. 2 Press the reset lever of positive pressure type demand valves. Do Not press centre of rubber cover while pressing the reset lever or force lever against the stop. See Fig. 1. Refer to Figure 1. (PA90A Illustrated.) % & Fig /0251

23 5:5 3 Remove the rubber cover (1) then using plate spanner R26817 unscrew and remove the bayonet cap (2). Press reset lever (3) - positive pressure type only. Carefully unhook diaphragm (4) from the lever (5) of the balanced piston assembly. Important Notes: The diaphragm of the lung demand valves must not be cleaned using ultrasonic techniques, as this will have a detrimental affect on the centrebonded area of the diaphragm. Clean and disinfect the diaphragm manually Fig Re-assemble the rubber cover (1) over the front of the lung demand valve to protect balanced piston mechanism. Immerse and manually agitate the demand valve, diaphragm and bayonet cap into cleaning fluid. (Refer to cleaning fluid instructions.) 5 After cleaning, rinse the components in clean water then immerse and manually agitate the demand valve, diaphragm and bayonet cap into disinfecting fluid. (Refer to disinfecting fluid instructions.) After disinfecting, remove rubber cover and rinse components in clean water, taking care not to damage balanced piston lever mechanism. 6 Press reset lever of the positive pressure demand valves to close balanced piston. 7 Connect the medium pressure hose of the demand valve to medium pressure air supply. Turn ON air supply then gently press the balanced piston lever to blow out fluid residue. Safety Note: Wear suitable eye protection. 8 Press reset lever of the positive pressure demand valves to close the balanced piston. Turn OFF and vent the air supply then disconnect medium pressure hose of demand valve from air supply. Thoroughly dry components. Note: Do Not exceed a temperature of 60 degrees Celsius when drying. 9 After drying insert the balanced piston lever into hole in centre boss of the diaphragm (chamfered side of boss towards lever) then carefully locate outer bead of diaphragm into groove in demand valve body. See Fig. 3 for correct orientation of the diaphragm.

24 5:6 10 Moisten lip of the bayonet cap with clean water - refit bayonet cap to the lung and using plate spanner R26817 tighten the cap to the demand valve. Note: Re-check orientation of diaphragm. See Fig Re-assemble rubber cover over the front of the demand valve then press the reset lever of positive pressure type demand valves. 12 Connect the demand valve to equipment and carry out Leak Test and Functional Test. Fig Replacing Diaphragm Tools required: Plate Spanner R26817 Refer to Figure 4 - (PA90A Illustrated) 1 Remove the rubber cover (1) then using plate spanner R26817 unscrew and remove the bayonet cap (2). Press reset lever (3) - positive pressure types only. Carefully unhook diaphragm (4) from lever (5) of balanced piston assembly. Scrap the diaphragm Fig Insert the balanced piston lever into hole in centre boss of the new diaphragm (chamfered side of boss towards lever) then carefully locate outer bead of diaphragm into groove in demand valve body. See Fig. 5 for correct orientation of diaphragm. 3 Moisten the lip of the bayonet cap with clean water - refit the bayonet cap to lung and using the plate spanner R26817 tighten the cap to the demand valve. Fig

25 5:7 Note: Re-check orientation of diaphragm. See Fig Re-assemble the rubber cover over the front of the demand valve then press the reset lever of positive pressure type demand valves. 5 Connect the demand valve to the equipment and carry out Leak Test and Functional Test. Fig Replacing Medium Pressure Hoses 0029 Fixed variants of the lung demand valve incorporate a medium pressure hose fitted directly to the medium pressure outlet port of the pressure reducer. These demand valves should also be removed from the reducer. For details of removal of hose from the reducer refer to the appropriate section of the relevant C.A.B.E. Training Manual Removing MP Hose (Elbow Connector) Tools Required: 10mm/11mm AF Open Ended Spanner mm AF Open Ended Spanner Disconnect demand valve from the female quick release coupling of the equipment. Refer to Figure Using 14mm spanner hold the banjo (1) across flats on banjo flange and using the 11mm spanner unscrew the elbow (2) of the hose from the banjo. Inspect the hose and if defective, scrap and replace. 3 Inspect the threaded bore of the banjo. If necessary clean and remove all traces of adhesive from the thread. Fig

26 5: Removing MP Hose (Straight Connector) Tools Required: Fine Point Circlip Pliers Screwdriver Hexagon Adaptor 2mm (Locking End Cap) Torque Key (Locking End Cap) Refer to Figure 7. 1 Disconnect the demand valve from the equipment and remove the end cap (1). Plastic End Cap - Insert screwdriver ( ) into radial slot of end cap and remove end cap. Scrap the end cap, replace with new. Locking End Cap Using 2mm adaptor and torque key unscrew the locking cap screw enough to enable the end cap to be removed. 2 Using fine point circlip pliers, remove circlip (2) from groove in the banjo. Remove washer (3). Scrap the circlip - Do Not re-use Fig Note: On positive pressure demand valves Do Not detach reset lever (4). If the lever becomes detached, reassemble the lever to the demand valve as detailed in Section Push end of the banjo and extract banjo and hose assembly (1) Fig. 8 from demand valve body. Check O- Ring (2) is on the banjo, if not, remove the O-Ring from bore of the demand valve housing. 2 1 Fig

27 5: Assembly of MP Hose (Elbow Connector) to Demand Valve Tools Required: 10mm/11mm AF Open Ended Spanner mm AF Open Ended Spanner Loctite Inspect the threaded bore of the banjo and if necessary clean and remove all traces of adhesive from the thread. Check that the O ring seal of the new hose is not damaged and is fitted correctly to the elbow. If necessary replace the O ring. 2 Screw the elbow of the new hose into the banjo by one revolution - apply one drop of Loctite 638 to thread of the elbow then finally screw the elbow into the banjo. Using 14mm spanner, hold the banjo across flats of the banjo flange and using the 11mm spanner tighten elbow to the banjo. Note: Do Not pressurise pneumatic system for 30 to 40 minutes to allow Loctite to set. Fixed variants of the lung demand valve should be fitted directly to the medium pressure outlet port of the pressure reducer. For details of fitting of hose to the reducer refer to the appropriate section of the relevant C.A.B.E. Training Manual. 3 Carry out Leak Test and Functional Test after 30 to 40 minutes Assembly of MP Hose (Straight Connector) to Demand Valve Tools Required: Molykote 111 grease Circlip Assembly Tool Hexagon Adaptor 2mm (Locking End Cap) Torque Key (Locking End Cap) Inspect and if necessary assemble new O-Rings into the grooves of the banjo (1) Fig 9. Before assembly of the banjo to the demand valve apply a coating of Molykote 111 grease around the outside diameter of O-Rings. 2 Carefully insert new banjo and hose assembly into bore of demand valve body, aligning the banjo through bore of balanced piston block and taking care not to detach the reset lever (2) of positive pressure demand valves. 2 1 Fig

28 5:10 Note: If reset lever becomes detached, reassemble lever to demand valve as detailed in Section Assemble washer (1) Fig. 10. Using the assembly tool assemble the circlip (2) into groove of banjo to secure banjo to demand valve body. Following assembly of the circlip check that the banjo swivels freely. 5 Fit new End Cap into bore of the banjo. Plastic End Cap - Insert new plastic end cap into bore of banjo. Locking End Cap Insert locking end cap into bore of the banjo and using 2mm adaptor and torque key tighten end cap to banjo torque to 0.7Nm. 2 Fig Note: Fixed variants of the lung demand valve should be fitted directly to the medium pressure outlet port of the pressure reducer. For details of fitting of hose to the reducer refer to the appropriate section of the relevant C.A.B.E. Training Manual. 6 Carry out Leak Test and Functional Test.

29 5: The Balanced Piston Unit PA90 Series lung demand valves incorporate a pre-set and sealed balanced piston unit. The Dräger guarantee is void should original seal, in sealing cone, be tampered with, or broken. Guarantee of correct operational condition of the balanced piston unit is only valid if serviced, and re-sealed, by Dräger. Replace with new factory set, or Repair Exchange balanced piston unit should problems occur (other than a requirement to replace springs on positive pressure type units). Balanced Piston Units will only be accepted for Repair Exchange after disassembly from demand valve, i.e. Balanced Piston Assembly only. For details of the Terms and Conditions of the Repair Exchange Scheme contact Dräger Service - Blyth. Replace complete balanced piston unit, or springs, as follows: Removing Balanced Piston Unit from Demand Valve Tools required: Plate Spanner R26817 Fine Point Circlip Pliers Posi-Drive Screwdriver Screwdriver Hexagon Adaptor 2mm (Locking End Cap) Torque Key (Locking End Cap) Molykote 111 Grease Loctite Connector Tool (PA90AE) Connector Tool (PA90N) Circlip Assembly Tool Remove the rubber cover (1) then using plate spanner R26817 unscrew and remove the bayonet cap (2). Press reset lever (3) - positive pressure types only. Carefully unhook diaphragm (4) from lever (5) of balanced piston assembly Fig

30 5:12 Refer to Figure Using posi-drive screwdriver unscrew retaining screw (1) until it is withdrawn from space in the castellation of connector (2). Note: Do Not attempt to remove pushin or screw-in connectors with the retaining screw in the castellation of the connector. 3 Remove connector. Push-in Type - A Unscrew push-in type connector (anti-clockwise) from demand valve body and remove antiinjector pipe (3) Fig /0127 Screw-in Type - AE Use connector tool ( ) to unscrew screw type connector and handwheel assembly from demand valve body. Remove anti-injector pipe. Screw-in Type - N Screw and tighten M40 handwheel to connector tool Turn handwheel and connector tool anti-clockwise to unscrew screw type connector and handwheel assembly from demand valve body. Remove anti-injector pipe. 4 Remove end cap (1) Fig. 13. Plastic End Cap - Insert screwdriver ( ) into radial slot of end cap and remove end cap. Scrap the end cap, replace with new. Locking End Cap Using 2mm adaptor and torque key unscrew the locking cap screw enough to enable the end cap to be removed Using fine point circlip pliers, remove circlip (2), from groove in banjo. Remove washer (3). Discard the circlip - Do Not re-use. Fig Note: On positive pressure demand valves Do Not detach reset lever (4). If lever becomes detached then reassemble lever to the demand valve as detailed in Section

31 5:13 6 Push end of the banjo and extract banjo and hose assembly (1) from demand valve body. See Fig. 14. Check O-Ring (2) is on the banjo, if not, remove the O-Ring from bore of the demand valve housing. 7 Remove balanced piston unit from inside demand valve body and if necessary return balanced piston unit to Dräger Service for replacement under the Repair Exchange Scheme Clean old grease from the banjo, inspect and if necessary replace the O-Rings. Fig Replacing/Refitting Return Spring Positive Pressure Demand Valves Note: Using a finger inside the demand valve body press the end of the positive pressure arm (1) Fig. 15 to prevent any axial movement. 1 Rotate the positive pressure arm (1) until the radial extension arm points towards outlet port of the demand valve body. 2 Insert return spring (2) into the housing recess with the radial arm of the spring located into the radial slot in demand valve body Hook the axial arm of the return spring (2) into the radial slot in the lever (3) - not onto hexagon - then carefully rotate the lever anticlockwise, against spring tension, until the first hexagon flat aligns with hexagon on the positive pressure arm. Press the lever onto the positive pressure arm. Fig Rotate the lever anticlockwise, carefully lifting the stop of the lever to the opposite side of the rib on the body of demand valve. At this position press the lever onto the positive pressure arm. 5 Check assembly and carefully press lever (3) against spring tension - lever should return freely under spring load.

32 5: Replacing Springs of Balanced Piston Unit - Positive Pressure Tools required: Fine Point Tweezers Remove Balanced Piston Unit from Demand Valve. Repeat instructions 1 to 9 in Section Refer to Figure Unhook closed loop of each spring (1) from locating lugs of balanced piston lever (2), then unhook open loop of each spring from pin of mounting block (3). Scrap the springs. Do Not re-use springs. 3 Using fine point tweezers assemble new springs to balanced piston block assembly as follows: Hook open loop, of each spring around the spigots of the mounting block (3). Using fine point tweezers hold the closed loop of each spring then extend each spring and hook closed loop onto locating lugs of balanced piston lever (2). Do Not over stretch the springs (x2) Fig Note: Position the spring on the plastic form side (4), under the pivot pin (5) as shown in Fig To re-assemble the Balanced Piston Unit to Demand Valve, repeat operation instructions 1 to 16 in Section

33 5: Assembly of Balanced Piston Unit to Demand Valve 1 Inspect and if necessary assemble new O-Rings into the grooves of the banjo. Before assembly of the banjo to the demand valve apply a coating of Molykote 111 grease around the outside diameter of the O- Rings. Safety Note: Carefully read instructions on Molykote 111 container regarding the handling of silicone grease. 2 Insert new balanced piston unit into demand valve body and locate onto internal location boss of demand valve body. See Fig. 17. Hold balanced piston in position by pressing with thumb against the end of seal cone. Fig Carefully insert banjo and hose assembly (1) Fig. 18 into bore of demand valve body, aligning the banjo through bore of balanced piston block and taking care not to detach the reset lever (2) of positive pressure demand valves. 1 Note: If reset lever (2) becomes detached, reassemble to the demand valve as detailed in Section Fig Assemble washer (1) Fig. 19. Using the assembly tool assemble the circlip (2) into groove of banjo to secure banjo to demand valve body. Following assembly of the circlip check that the banjo swivels freely. 5 Position and hold demand valve with outlet port in vertical position. Insert the anti-injector pipe (1) into the port and locate onto the balanced piston block. See Fig Fig

34 5:16 6 Assemble connector. Push-in Type - A Assemble new O-Ring (2) Fig. 20 to connector. Apply Loctite 245 to connector thread and screw connector (3) into demand valve body. Tighten until antiinjector pipe is secure. Do Not overtighten. Screw-in Type - AE Check handwheel freely rotates on connector handwheel assembly and that retaining circlip is secure. Assemble new O- Ring to connector handwheel assembly. Apply Loctite 245 to connector thread. Using tool ( ), screw connector handwheel assembly into demand valve body until antiinjector pipe is secure. Do Not overtighten. Fig /0127 Screw-in Type - N Check handwheel freely rotates on connector handwheel assembly and that retaining circlip is secure. Assemble new O-Ring to connector handwheel assembly. Apply Loctite 245 to connector thread. Screw and tighten handwheel into tool and screw connector handwheel assembly into demand valve body until anti-injector pipe is secure. Do Not overtighten. 8 Carefully turn connector anti-clockwise till first space, in castellations on end face of connector, is in line with retaining screw hole. Fully tighten the retaining screw to secure the connector to the demand valve body making sure the screw enters space in the castellation. Note: Remove assembly tools from handwheel connectors of AE and N type demand valves. 9 Check again that the banjo swivels freely. 10 Positive Pressure Demand Valves Press the reset lever, checking that spring loaded lever of the balanced piston lifts and, on releasing the reset the lever the spring loaded lever holds in position. Gently press the end of balanced piston lever checking it releases from locking plate and retracts freely under spring load. Repeat check. Press reset lever to lift and hold the balanced piston lever.

35 5:17 11 Insert the balanced piston lever into hole in centre boss of the new diaphragm (chamfered side of boss towards lever) then carefully locate outer bead of diaphragm into groove in demand valve body. See Fig. 21for correct orientation of diaphragm. 12 Moisten the lip of the bayonet cap with clean water - refit the bayonet cap to lung demand valve and using plate spanner R26817 tighten the cap. Note: Re-check orientation of diaphragm. See Fig. 21. Fig Positive Pressure Demand Valves Press the reset lever, checking that diaphragm lifts and then on releasing the reset lever that the diaphragm holds in position. Do Not press the centre of the diaphragm when pressing reset lever, or force lever against stop. Press the centre of diaphragm gently, checking it releases and retracts under spring load. Repeat check. 15 Fit new End Cap to banjo. Plastic End Cap - Insert new plastic end cap into bore of banjo. Locking End Cap Insert locking end into bore of banjo and using 2mm adaptor and torque key tighten end cap to banjo torque to 0.7Nm. 16 Assemble rubber cover to the demand valve then carry out Leak Test and Functional Test.

36 6:0 Section 6 Test Procedures

37 6:0 Contents Section Description 6.1 Test Procedures

38 6:2 6.1 Test Procedures The PA90 Series of Lung Demand Valve are approved for use with approved Dräger Compressed Air Breathing Equipment (C.A.B.E.). Standard test procedures for C.A.B.E. are as follows and are covered in the relevant Training Manual for the C.A.B.E.! Cylinder Pressure Check and Valve Leak Test! High Pressure Leak Test! Whistle Warning Unit Test! Full Flow Test! Medium Pressure Test - Pressure Reducer For detailed instructions of the following Functional Tests relating to the testing of the lung demand valve and associated ancillary items refer to the appropriate Test Equipment Manual. Type A and AE! Balanced Piston Leak Test! Positive Pressure Balance Test! Static Pressure Test! Positive Pressure Switch Over Type N! Balanced Piston Leak Test! Demand Valve Opening Pressure

39 1167 PA90 Series - Lung Demand Valve 6:3

40 7:0 Section 7 Fault Location

41 7:1 Contents Section Description 7 Fault Location 7.1 Demand Valve

42 7:2 7 Fault Location 7.1 Demand Valve The high performance PA90 Series lung demand valves incorporate a pre-set and sealed balanced piston unit that has unlimited service life. The Dräger Warranty and Guarantee is void should any attempt be made by customers to make adjustment to the balanced piston unit. Guarantee of correct operational condition of the balanced piston unit is only valid if serviced, and re-sealed, by Dräger. Replace with new factory set or Repair Exchange balanced piston unit if problems occur (other than a requirement to replace springs on positive pressure type units). Balanced Piston Units will only be accepted for Repair Exchange after disassembly from demand valve, i.e. Balanced Piston Assembly only. For details of Terms and Conditions of Repair Exchange Scheme contact Dräger Service - Blyth. The following Fault Cause Remedy chart outlines a list of possible faults that may occur. FAULT CAUSE REMEDY Leak from pressure relief valve of medium pressure hose Damaged O-ring Weak Spring Damaged O-ring retainer Replace O-ring Replace spring Replace retainer Leak from pressure relief valve of medium pressure hose. Relief valve components O.K. Reducer failure Remove hoses from reducer and return reducer to Dräger. (REX) High Medium Pressure Reducer out of specification Remove hoses from reducer and return reducer to Drâger. REX) Low Medium Pressure Reducer out of specification Remove hoses from reducer and return reducer to Drâger.(REX) Medium pressure High after one minute Continuous creep High Pressure Leak Remove hoses from reducer and return reducer to Drâger.(REX)

43 7:3

44 8:0 Section 8 Spare Parts Lists and Tool List

45 8:1 Contents stm PA90 Series Lung Demand Valve Tool List