Aqua Lung MISTRAL SECOND STAGE Technical Maintenance Manual Download Page 10

10   

CAUTION:

 Do not unscrew the crown more 

than a ½ turn, relative to the pre-set adjustment 
obtained using tool (p/n 125727) in step 3 in 
the reassembly procedures.

NOTE

:

 Before performing the following

proceedure, refer to 

Table 5: Test Bench 

Specifi cations (p. 15)

.

NOTE

:

 Test 2, 3 and 4 require the use of a

regulator test bench.

   

b. Align the mold lines on the corrugated hose and box.            

           Install the “R” clamping band so that the lugs are in    

           the same line as the fi rst stage body. Using a small   

           blade screwdriver, tighten all clamping bands.

c. Check that the corrugated hose mold line is identical  

 

     with that shown below when the regulator is laid fl at  

 

     with the mouthpiece pointing upwards.  

THIS ENDS REASSEMBLY

FINAL TESTING PROCEDURES

Second Stage Opening Effort Test

1.  Connect the fi rst stage regulator to a calibrated test bench 

and pressurize the system to 3000 (±100) psi.
2.  Turn the fl owmeter control knob shut, and then slowly 

reopen while watching both the magnahelic gauge and the 

medium pressure gauge. Turn the fl owmeter control knob 

shut, and then slowly reopen while watching both the 

magnahelic gauge and the medium pressure gauge.
   

a. If the opening effort is too low, disassemble the 

       second stage to give access to the lever: disassembly    

       steps 3-7. Screw in the crown (16) 1/2 a turn using 

       a screwdriver.

Readjust the lever height, see step 15 then reassemble

the second stage to the end. 

   

b. If the opening effort is too high, disassemble the 

   

second stage to give access to the lever: disassembly  

   

steps 3-7. Unscrew the crown (16) 1/2 a turn using a    

   

screwdriver.

CAUTION:

The mold lines on the corrugated 

hoses should fi t over those on the inhalation 
and exhalation boxes.

Readjust the lever height, see step 15 then reassemble

the second stage to the end. 
3.  Flow/depression test

. Adjust the inhalation fl ow to 

15 SCFM check that the depression does not exceed 

+6 in./H

2

O. If the depression is higher than this check 

Table 1: Troubleshooting Guide

.

4.  

Leak test

. Connect the fi rst stage to a cylinder charged 

to 2500-3000 psi, open the valve and immerse the complete 

set into a bath of water for 1 minute. Check that there are 

no leaks. If there are still leaks, completely disassemble the 

second stage and inspect all sealing surfaces and the correct 

fi tting of all parts.

Summary of Contents for MISTRAL SECOND STAGE

Page 1: ...Authorized Technician TECHNICAL MAINTENANCE MANUAL MISTRAL SECOND STAGE...

Page 2: ...Y PROCEDURE 6 FINAL TESTING PROCEDURES 10 Second Stage Opening Effort Test 10 Table 1 Troubleshooting Guide 11 Table 2 List of Tools and Service Kits 12 Table 3 Recommended Cleaners and Lubricants 13...

Page 3: ...the hose crimps If a regulator fails item 1 2 3 or 4 the entire regulator should be overhauled If a regulator fails 4 5 6 or 7 it will be up to the technician s discretion whether or not a full overha...

Page 4: ...the surface is clean and unscratched It should be exible and have a clean edge If it is in good condition it is not necessary to replace it If there are any signs of deterioration it should be replac...

Page 5: ...condition of the lever 10 and the spring 13 to ensure it is not bent corroded or other wise damaged If any signs of damage are found discard the part and do not reuse 12 Place the handle of the seat e...

Page 6: ...amage to the sealing edge 17 Remove the o rings from the crown and the inlet tting THIS ENDS DISASSEMBLY Before starting reassembly perform parts cleaning and lubrication in accordance with Procedure...

Page 7: ...er the sealing edge of the crown 7 Place the poppet bearing 12 over the pin of the extraction tool with the square feature facing up Guide the pin of the tool into the open end of the valve body 11 an...

Page 8: ...ew in the inlet tting snug by hand while pressing the lever down 14 Using a torque wrench and a 3 4 19mm crows foot torque the inlet tting 19 to 85 in lbs 15 Fit new lubricated o rings to the MP hose...

Page 9: ...ever touching the tool there should be no leaks Once the adjustment is completed turn off the air supply and purge the regulator 19 Install the sealing ring 4 onto the diaphragm 5 and place the assemb...

Page 10: ...b shut and then slowly reopen while watching both the magnahelic gauge and the medium pressure gauge a If the opening effort is too low disassemble the second stage to give access to the lever disasse...

Page 11: ...pring 12 is damaged 7 Replace the spring Breathing effort is too high 1 MP is too high 1 Readjust the lever and the crown 2 The lever 9 is adjusted too low 2 Readjust the lever and the crown 3 The MP...

Page 12: ...ing bands 944022 O ring removal and installation N A 3mm Allen Keys Assemble disassemble casing N A Cleaning inside of corrugated hoses N A Removing panduit clamps 900016 Service Kit MISTRAL Crown and...

Page 13: ...r reusable stainless steel and brass parts Household grade Liquid dishwashing detergent diluted with warm water Degreaser for brass and stainless steel parts general cleaning solution for plastic and...

Page 14: ...e stubborn deposits household white distilled vinegar acetic acid in an ultrasonic cleaner will work well DO NOT place plastic rubber silicone or anodized aluminum parts in vinegar 3 Remove parts from...

Page 15: ...CRIPTION KEY ITEM TORQUE 104106 Inlet tting 19 85 in lbs Table 5 Checking Speci cations TEST CONDITION SPECIFICATIONS Leak Test Inlet 2500 3000 100 psig No leaks allowed Opening Effort Inlet 2500 3000...

Page 16: ...16 Maintenance Notes...

Page 17: ...900016 Overhaul Parts Kit Entire Mistral 1 125929 Screw caphead 2 125935 Exhalation box 3 129174 Exhaust valve 4 124509 Sealing ring 5 125705 Diaphragm 6 125937 Inhalation box 7 7 7 125928 Locknut 8 8...

Page 18: ...Authorized Technician TECHNICAL MAINTENANCE MANUAL MISTRAL SECOND STAGE Aqua Lung America 2340 Cousteau Court Vista CA 92081 760 597 5000 www aqualung com Rev 2 2006 Aqua Lung USA Aqua Lung USA...

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