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1. Overview (1) The availability of subassemblies and components, repair parts, specialized tools, and maintenance manuals does not imply qualification to assemble and/or service scuba equipment. Improper service of dive equipment can lead to severe injury or death. Dive Gear Express recommends that nonqualified individuals seek professional training/mentoring before attempting repairs or servicing on any diving equipment Failure to follow the procedures outlined herein may result in injury or death! (2) In the following pages will be found, the disassembly, assembly, tuning, and troubleshooting steps for these components. Photos are used throughout to illustrate the procedures. Please pay special attention to all caution notes! (3) Whenever an item of extra importance needs to be observed, a “Caution Note:” will appear, followed by the required information. See below. Caution Note: This must be read and followed! (4) Included in this manual is a list of recommended/required tools for each disassembly, assembly, and testing section. They are identified in each section where they are used. (5) ...
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Cleaning and Rinsing General Considerations (11) Cleaning and rinsing of the components should be done using clean, fresh water. If available, distilled water is recommended to maintain oxygen cleanliness. (12) Only use degreasers that leave no organic residue (clear Simple Green, dyefree Dawn dishwashing liquid, or Blue Gold Cleaner as examples). (13) To deal with corrosion, use a 50/50 vinegarwater solution and nylon brushes. (14) Allow parts to air dry without the use of cloths that may leave fibers. For regulators that are going to be used with Oxygen percentages above 40%, a UV light is strongly recommended to check for organic contamination. (15) Once all service procedures have been completed and bench testing done, in water testing in a confined environment ...
Inspection After Cleaning (21) Before assembling the regulator, it is necessary to inspect all of the cleaned components. Using the magnifying glass, check all the components for damage that may have been hidden by corrosion or lubricant. Look for scratches that may affect the sealing of the regulator. In a darkened room, use the UV light to look for organic material. It will show up as glowing lines or fragments. If any are present, the part needs to be re cleaned and dried! This is critical for use with oxygen percentages above 50%! (22) Another way to check for residual lubricants is to fill a tray with clean, fresh, water deep enough to cover the parts by an inch or so. Lay the components in the water and circulate the water around them. Allow the pieces to soak for several minutes and the water to settle. Once it has settled, look for a rainbow sheen on the surface of the water. Any residual lubricants will float and form a “slick” on the surface. If one is present, the parts must be cleaned again. (23) Now that all parts have been cleaned and checked, the assembly can begin. Make sure all old parts that are to be replaced have been discarded or segregated. Remove the new parts from the service kit bag and lay them out in the order they will be used. Do not take the new parts out of the bags yet! Caution Note: Removing parts from their individual bags, before they are to be used, runs the risk of mixing them up. Some orings are very close in size but are not interchangeable! Keep the parts in the bags until you actually need them. (24) As with the parts that have been cleaned, it is a good idea to inspect the new parts as well. Especially the HP seat. Make sure it is free of any defects. Check all of the orings and inspect them as you use them for nicks or other concerns. Inspect the washers to ensure they are free of excess burrs or other concerns that could affect their function. It is also a good idea to use the parts list on the schematic to ensure that all of the new parts that are needed are present and accounted for in their required quantities. (25) Lubrication of Orings; Lubrication can be overdone. Doing so runs the risk of trapping excess dirt or debris on the parts. One way of reducing the risk of overdoing it is to use the lubeinabag method. This involves using a small clean plastic bag and putting a small amount of lube in it. Then the oring is inserted into the bag, worked around, excess squeezed off, and taken out of the bag, and used in its location. Fig. 1 Fig. 2 ...
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(26) Another way is to apply a small amount of Tribolube to the gloved index finger and massage the oring between the thumb and index finger. Either way works, but the bag method tends to give better distribution results and uses less lubricant. (27) Under most circumstances, a lubricant is used correctly very sparingly or not at all. In nearly all scuba applications, if you can see the lubricant, you’ve used too much. Before using any lubricant, any existing lubrication should be removed before new is applied. In dynamic applications, it is used to reduce excessive wear. Static orings do not generally require the use of lubricant. (28) Where parts are not necessary to be lubricated, it is good practice to avoid getting any lubricant on them. Primarily when the regulator is used with high O2 content mixes. It also helps to keep those parts clean and free of debris that will cling to the lubricant. (29) Maintaining oxygen clean conditions for 2nd stages is technically not mandatory. The 2nd stage is a low pressure device operating at 135 psi. Regardless, best practice is to maintain oxygen clean conditions along with the exclusive use of oxygen compatible lubricants when servicing the regulator. The next section lists the tools you will need to service the regulator. ...
2. TOOL LIST (1) The tool list for the second stage is not as extensive as that for the first stage. They are still divided into Required and Recommended. The required tools are necessary for servicing the regulator. Recommended are those items that make servicing easier or more efficient as well as lessening the chance of damage. Required tools Fig. 3 2 Adjustable Wrenches (thin jawed) or thin 11/16 wrench and proper wrench for LP hose 3/16 hex wrench Brass Picks for removing orings Tribolube 71 Soft Bristle Cleaning Brushes (Nylon) Inline second stage adjustment tool with slotted orifice selected Wooden or plastic dowels Recommended tools Fig.4 1. Soft Rubber Pad 2. Magnifying Glass 3. Flashlight 4. UV light 5. Magnahelic Gauge with 03 inches of water scale Fig.5 6. Waterproof Ruler/Scale for testing when no magnahelic is available (2) You can purchase tools from Dive Gear Express. The InLine Adjusting Tool with IP gauge, Brass Picks, and the IP Gauge that is shown that plugs into the LP inflator hose can be found at the link below. https://www.divegearexpress.com/tools/scubatools Phone: 9549776009 ...
3. Preliminary Testing (4) Preliminary testing of the regulator is necessary to identify any issues with the first and second stages and verify the overall regulator function. This testing will include: 1. Visual inspection of the first and second stages 2. Inspection of the hoses 3. Intermediate Pressure check 4. Cracking Pressure and Second Stage Negative Pressure Test Visual inspection is done to identify issues that could affect servicing and to ensure that pressurizing the system will not compromise the safety of the service technician. The technician will check all connections to make sure they are secure. The technician will check that on the first stage, there are no extruded orings, and hoses are tight. The technician will check there are no defects to the SPG. The technician will ensure that the DIN assembly is secure, and the O ring is intact and able to form a seal. The technician will inspect the filter for signs of discoloration. Detailed Inspection of Hoses is done to ensure it is safe to pressurize the regulator set. The technician will check all hoses, looking for evidence of possible failure. The technician will check all hose connection crimps. Defects must be taken care of before pressurizing the system! Replacement of any suspect hoses is recommended. Caution Note: Defects in hoses require replacement before pressurizing the regulator! Failure to do so may result in serious injury or death! (5) Detailed Visual Inspection of the SPG and connection – The technician will check the SPG for any signs of cracking of the face, water intrusion, and corrosion around the SPG to the hose connection. If using a console or boot, it is necessary to remove the SPG from the rubber boot. Once this is done, the HP spool should be inspected and, if necessary, replaced. (6) Checking of Intermediate Pressure (IP) – The Intermediate Pressure (IP) of the system should be tested only after the preceding checks have been done to ensure technician safety. Checking of intermediate pressure is done by attaching an intermediate pressure gauge to the LP pressure inflator hose. The system is ...
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Caution Note: If the second stage is leaking even slightly, IP will be affected. If the second stage is leaking, turn the adjustment knob to stop it or use a second stage that is not leaking through when paired with the first stage. It is also a clear indication that the second stage requires rebuilding if turning the adjustment knob does not stop the flow. (7) The standard operating range for the system is with an IP of 135 PSI. Ideally, the system is operating at 135 PSI +/ 5 PSI and show no signs of “creep” or instability at 3000 PSI. Caution Note: “Creep” will show as the IP steadily increasing while the regulator is not in use. Normally the IP will drop 510 PSI during a breath or purge and then return to its setting. It should not return to the setting and keep increasing. This would indicate a problem with the highpressure seat, Piston, or sealing orings. (8) If the system shows no sign of creep or IP instability, it is generally not necessary to rebuild the 1 stage with some exceptions. Caution Note: If the unit shows signs of internal corrosion or the filter shows evidence of contamination, the unit must be rebuilt! Regardless of the Intermediate Pressure. (9) The regulator will require rebuilding if small bubbles are leaking from between the turret retainer and main body, from under the rubber cap, or out of the highpressure seat retainer. Knowledge of flooding of the first stage will also require the unit to be rebuilt. Freshwater contains dissolved minerals and other materials that, due to internal corrosion over time, may cause the regulator to malfunction. (10) After the IP has been checked, hoses and regulator body inspected, and SPG evaluated, the second stage inspection can take place. It is necessary to perform an inspection of the 1 stage and check the intermediate ...
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4. Second Stage Evaluation Negative Pressure and Cracking Pressure evaluation – (1) The negative pressure test verifies the main and exhaust diaphragm seals as well as case integrity. With the supply pressure off, and attached to a cylinder, attempt a normal breath from the second stage. You should be unable to draw any air. If a flow is obtained, remove the second and try with a thumb over the air inlet to it. If a flow is still present, the primary and exhaust diaphragms need to be checked for damage. Salt accumulation, sand, and defects in the case will also allow airflow when the air inlet is covered. Carefully check all of these. (2) Cracking pressure testing is most accurately done with the use of a magnahelic gauge. A container of water can be used by measuring the depth to which a stage can be submerged facedown parallel to the water. This gives an indication at which level of effort the second stage will open. The normal range for the adjustable second stage is 1.0 to 2.2 inches of water. Less pressure may be desired by the diver, but the initial factory setting of 1.1 should be used. This permits a breakin period for the LP seat. It is normal to see this initial setting drop as the LP seat takes a set. Second Stage Case Integrity – (3) The case should be inspected for signs of damage. Scratches, gouges, missing parts, damaged exhaust ports, or loose faceplate that will not tighten may be an indication of a damaged case. (4) Use a negative pressure test, test the purge button, and look for defects. Check the lever and breathing effort knob. Do they move freely and with no indication of stiffness? Do they feel like there is sand or grit in them? (5) A problem with case integrity should be dealt with before starting the rebuild. A defective case will compromise final testing and pose a safety hazard to the user. ...
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Second Stage Disassembly . (1) In the following steps, the part numbers from the schematic will be used with their description. Have the schematic in front of you while following the instructions! Be sure to keep all old parts organized and separate from new ones in the service kit! 1. Remove the Second Stage from the hose after depressurizing the system. Unscrew the Case Cover (41) from the Case (11) and remove the Cover (3), Diaphragm Cover (4), and the Diaphragm (06) and Diaphragm Disc (05) assembly. Fig. 6 This reveals the Valve Spindle Assembly in the case. Fig. 7 Fig. 6 Fig. 7 2. Remove the Retaining Nut (08). Holding the Lever (20) down, slide/pull the Valve Spindle Assembly out of the case as one unit. Fig. 8 Fig. 8 3. Slide the Venturi Lever (18) off of the spindle while holding down the Lever (20). Be careful after sliding the Venturi Lever (18) off to allow it to come up slowly. Fig.9 Fig. 9 ...
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4. With the lever off, using the brass pick blunt end or another suitable tool, press the Spring Pin (21) out of the Valve Spindle (19). Note that this may require some force to remove. Secure the spindle as needed. This will allow the Adjusting Screw (30) to be removed. Remove the Rubber Cap (35) from the Adjusting Screw (30).
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6. Once you have removed the assembly from the Spindle (19), use the slotted end of the inline adjustment tool to remove the Orifice (15) from the Spindle(19). The photo below shows all of the parts to the Spindle Assembly. Item Oring (23) is located in a groove on the inside of the Spindle. Fig 12. Fig.
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8. Using the pinch method or a brass/plastic pick, remove all of the Orings from the Lever (18), Orifice (15), Shuttle Valve (25), Adjusting Screw (30), and Adjusting Spring (34). Fig. 15. Confirm that all are accounted for and segregate them with the other replaceable parts. Fig.
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Second Stage disassembled Second Stage Service Kit...
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6. Second Stage Assembly (1) Before starting the assembly of the second stage, complete a thorough inspection of all parts to be re used. Refer to the Overview Inspection section for details. At this time, open the service kit and lay out the parts.
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3. Using the InLine Tool, insert the Orifice (15) into the threaded end of the Spindle (19) – Fig. 20, and when the threads engage, turn it in 34 turns. Actual adjusting of the Orifice will be done later. – Fig. 21 Fig. 20 Fig. 21 4. Assemble the Shuttle Valve (25), Spring (27), and Counter Balance Cylinder (28). With the assembly oriented, as shown in Fig. 22, insert it into the Spindle (19). Pay special attention to the position of the notch on the Shuttle Valve. This is where the Lever (20) engages the Shuttle Valve. It must be oriented in this manner. Note also the position of the hole for the Spring Pin (21). – Fig. 22. Lever removed for clarity. ...
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6. Once the notch is lined up, carefully insert one tab of the lever to engage it and rotate the spindle so that the other leg of the lever drops into the corresponding window on the other side. Do not bend the legs of the lever! – Fig. 24. Fig. 24 7. Allow the lever to come down to rest and carefully set the assembly aside. Fig. 25. Fig. 25 8. Assemble the Adjusting Screw (30) and Adjusting Spring (34) – Fig. 26. A trace of lubricant on the threads of these will help to ensure smooth operation. The initial adjustment on the Adjustment Spring is to have approximately 1mm of the spring end showing above the end of the Adjusting Screw (34), as shown. – Fig. 27 Fig. 26 Fig. 27 ...
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9. Carefully insert the Adjustment Screw (30) and Spring (34) assembly into the Spindle (19) and begin to screw it in. The lever will rise as this is done. Screw the assembly in until you can see clearly through the hole for the Spring Pin (21). – Fig.28 Fig. 28 10. Insert the spring pin and push it into place with the blunt end of the brass pick. Fig. 29. The sharp brass pick may be used to guide it in. An equal amount of pin should be present on each side. If this is not done, the Venturi Lever may hang up on the pin that is sticking too far out. Fig. 29 11. Place the lubricated Oring (17) on the Venturi Lever (18) and slide it onto the Spindle/Lever assembly. Make sure that it moves freely around the Spindle (19). Note the position of the lever relative to the air outlet. Fig. 30. Fig. 30 ...
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12. Slide the complete assembly into the Case (11). Ensure that the lever fits between the tabs in the Case and is seated, as shown. Ensure that the Lever (20) moves freely. Place the Oring (09) on the threaded end of the Spindle (19). – Fig. 31. Place the Retaining Nut (08) on the Spindle and thread it on. Tighten with the ths 11/16 wrench. Fig. 32. Do not overtighten as this can crack the case! Fig. 31 Fig. 32 13. Turn the Case so that the Adjusting Spring (34) can be seen. – Fig.31. Install the Rubber Cap (35) onto the Adjusting Screw (30) to cover the spring. Fig.32 Fig. 33 Fig. 34 14. Using the InLine Adjusting Tool, while depressing the Lever (20), turn the orifice so that the Lever (20) is even with the face of the Case (11). Only turn the orifice when the lever is depressed to avoid cutting the LP seat! This is the preliminary adjustment of the cracking pressure. The final adjustment will be made with the tool when the second stage is pressurized. – Fig. 35 Fig. 35 ...
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15. Assemble the Diaphragm (06) and Disc (05) by gently stretching it and allowing it to go into the groove. – Fig. 36. Make sure there are no wrinkles and that the rubber is evenly seated. Place it in the Case (11). Place the Diaphragm Cover (04) in position. – Fig. 37. Fig. 36 Fig. 37 16. Place the Cover (03) and secure it with the Case Cover (41). – Fig.38. If the Exhaust Valve (12) has been replaced and the Cover Exhaust Valve (13) has been removed, it can now be replaced. – Fig. 39. Reinstall the Mouthpiece (14) and secure it with a zip tie. Fig. 38 Fig. 39 This completes the assembly of the second stage.
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6. Second Stage Testing and Adjustment (1) Second stage testing and adjustment can be accomplished by using a regulated supply or any cylinder of air. There is no required supply pressure due to the second stage being supplied by a first stage delivering air at the Intermediate Pressure.
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7. Testing for Cracking Pressure (1) Cracking pressure is the effort required to depress the lever and allow air to flow through the second stage. It is measured in inches of water. A Magnehelic is one method of doing this. The gauge is attached to the second stage, and a normal breath is taken.
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