PN RG300
Service & Repair Manual
Revised - 02/11
AltAir Octo
Section 1 - Introduction
Scheduled Service................................................................................................................................. 3
EAN/ Nitrox Service................................................................................................................................ 3
Facility Requirements............................................................................................................................. 4
Specialty Tools........................................................................................................................................ 5
Section 2 - Preliminary Inspection
External Inspection................................................................................................................................. 6
Immersion / Leak Test............................................................................................................................ 6
Section 3 - Disassembly Procedures
General Guidelines................................................................................................................................. 7
Section 4 - Reassembly Procedures
General Guidelines................................................................................................................................11
Section 5 - Final Testing Procedures
Subjective Breathing Test..................................................................................................................... 16
Flowbench Testing (optional)................................................................................................................ 16
External Leak Test................................................................................................................................ 17
Troubleshooting Guide................................................................................................. 18
Schematic & Parts List............................................................................................. 19
AltAir Octo Service and Repair Manual
Service & Repair Manual
This manual provides factory prescribed procedures for the correct service and repair of
the AltAir™ second stage regulator. It is not intended to be used as an instructional manual for
untrained personnel. The procedures outlined within this manual are to be performed only by
personnel who have received factory authorized training through a repair seminar that has been
directly sponsored by XS Scuba.
If you do not completely understand all of the procedures outlined in this manual, contact XS
Scuba to speak directly with a Technical Advisor before proceeding any further.
Warnings, Cautions, & Notes
Pay special attention to information provided in Warnings, Cautions, and Notes that are accompanied by one of these symbols:
A WARNING indicates a procedure or situation that may result in serious injury or death if instructions are not followed correctly.
A CAUTION indicates any situation or technique that will result in potential damage to the product,
or render the product unsafe if instructions are not followed correctly.
A NOTE is used to emphasize important points, tips, and reminders.
Scheduled Service
Because the AltAir™ regulator is considered to be a life-supporting product, it is extremely critical that it receives
service according to the procedures outlined in this manual on a regularly scheduled basis; at least once a year with
normal or infrequent use.
NOTE: A unit that receives heavy or frequent use, such as in rental, instruction, or commercial applications, should be serviced at least twice each year - or more often - depending on the conditions of use and the manner in which it is maintained. (Refer to the
care and maintenance procedures outlined in the AltAir User's Guide.)
When performing service, whether it is a routine overhaul or a repair of a specific problem, it is important to
understand how the regulator is designed and how it operates. If you have any questions, please consult your XS
Scuba representative.
EAN/ Nitrox Service
Newly manufactured XS Scuba regulators are assembled and packaged to be compatible with oxygen enriched
air (EAN/ Nitrox), not to exceed 40% oxygen content. If the regulator is going to be used for this application, however, it must be dedicated and clearly labled as such, in order to prevent any crossover use with standard compressed
air. Refer to the instructions provided in the XS Scuba Authorized Service Document, titled - Regulator Parts
Cleaning Procedures.
CAUTION: It is important to avoid using, testing, or otherwise pressurizing a dedicated
EAN regulator with standard compressed air, which contains hydrocarbon contaminants.
Copyright ©2011 XS Scuba
AltAir Octo
Facility Requirements
As an Authorized XS Scuba Dealer, your customers expect
you to provide top-notch overhaul service, both before and
after the sale. Next to airfills and gas blending, it is the single
most important commodity your store can provide.
The service department is therefore the most important
part of your store. It should be clean and well lighted, and
stocked with a complete inventory of parts and all the specialty
tools you will need to get the job done right. As a minimum
requirement, your service facility should be equipped with the
following items:
❏ Ultrasonic Cleaner – Select the right size model that can keep up with
the volume of equipment that your store services. A built in timer and
heater will help control the cleaning time and temperature of the solution, since most solutions work best when heated.
Ultrasonic Cleaner
❏ Bench Mounted Vise – A vise is sometimes needed to hold the regulator secure – especially when removing the first stage yoke retainer.
Special care must be taken, however, to avoid damage that can result
from improper use of this tool. Be sure to follow the instructions provided in this manual.
NOTE: XS Scuba especially endorses and recommends the Jaws
Gripmaster Bench Vise, available from Peter Built Co. It is designed
specifically for the professional dive store service bench, and will prevent damage that can easily be caused by a conventional vise.
❏ Magnification Lamp – Strong lighting and magnification are essential
requirements for performing a thorough parts inspection - especially
when locating the source of a small leak.
"Jaws" Gripmaster Vise
❏ Quality Wrenches & Sockets – When working with brass parts, it is
especially critical to use the correct size wrench and to ensure that it
fits properly over the part. The use of an adjustable wrench is very
likely to cause damage to your customer's equipment, and should be
strictly avoided at all times.
❏ Calibrated Inch-Pound and Foot-Pound Torque Wrenches –
It is important to follow the manufacturer's torque values whenever they
are specified, in order to avoid overtightening or undertightening a part.
This is especially important for smaller parts and fittings, when overtightening can easily damage the part. Torque wrenches that can be
set for both inch-pound and foot-pound measurements tend to be less
accurate than wrenches that are designed to measure torque within a
specific range.
AltAir Octo Service and Repair Manual
Service & Repair Manual
Specialty Tools
For the finest tools, fixtures, and supplies that are designed and manufactured specifically for
servicing SCUBA equipment, we recommend one source for all your service facility’s needs.
Peter Built Co., in Galion, Ohio, is dedicated to serving the diving industry, and offers a wide
selection of the most innovative specialty tools found anywhere to help you get the job done
efficiently - and done right.
Select Tool Kit (5 pcs) # 11-090-500
260 2.0 x 50
260 3.5 x 60
O-ring Tool Set #10-102-100
125-150 PSI
125-150 PSI
the making"
in the making"
(419) 468-2212
(419) 468-2212
Dual Drive In-Line Adjusting Tool # 20-500-200
Intermediate Pressure
Test Gauge, #20-510-100
Alt Air Retaining Ring Clamp # 20-795-200
Illustrations courtesy of Peter Wolfinger.
Required Tools/ Lubricant
Dual Drive Adjusting Tool PN #20-500-200
Tech Driver IPG
PN #20-165-111
O-ring Tool SetPN#10-125-400
1/4" Slotted Screwdriver
PN #11-465-500
1/4" Nut Driver
PN #11-168-500
Small (.02) Blade Screwdriver
PN #11-133-500
Cristo LubePN #MS150
Hakko Side Cuts, 5"
PN #16-020-500
11/16" Open End Wrench
3/4" Open End Wrench
Galion, OH 44833
Phone: 419-468-2212
Copyright ©2011 XS Scuba
AltAir Octo
Preliminary Inspection
External Inspection
1. Closely examine the conical filter inside the first stage
yoke to check for any signs that contaminants have
entered the system, including sea water, rust, or
aluminum oxide.
NOTE: A green discoloration of the filter indicates
that moisture has entered the regulator, and internal
corrosion has possibly occurred. Other types of
discoloration may indicate that the regulator has been
used with a corroded cylinder. Advise the customer
of this, and the possible need to obtain service for the
2. Slide back the hose guards, if present, to visually inspect
the condition of the hoses at their fittings.
3. Check the overall condition of the mouthpiece, exhaust
grill, and other external parts to evaluate the type of use
and maintenance the regulator has received.
Immersion / Leak Test
1. Check to ensure that the regulator is fully assembled and
connected to a first stage, and that there are no open
ports or hoses. Connect the first stage to a cylinder that
is filled with 3,000 psi, and open the cylinder valve to
pressurize the regulator.
2. If leakage cannot be heard, or if the source of leakage
detected audibly is not obvious, immerse the first stage in
fresh water to check further for any signs of air leakage,
especially at the fittings of hoses.
3. Note the source of any leakage found and refer to
Troubleshooting Guide to determine its possible cause.
4. Close the cylinder valve and depress the second stage
purge button to depressurize the regulator before
performing the next procedure.
AltAir Octo Service and Repair Manual
Service & Repair Manual
Disassembly Procedures
General Guidelines
▼ Prior to performing any disassembly, check to ensure that
the service facility is well equipped with all the tools and
parts needed to perform a complete service from start to
finish. DO NOT attempt to perform the service unless all
of the required tools and parts are available.
▼ All o-rings are classified as being either dynamic or
static. Dynamic o-rings are those which sustain friction
and movement, as they are either mounted directly onto
a moving part, or create a seal against a moving part.
Static o-rings simply create a seal between two nonmoving parts, and are therefore less subject to wear than
dynamic o-rings. After passing close inspection, static
O-rings may sometimes be reused, although this is not
necessarily recommended. Dynamic O-rings must
be automatically discarded and replaced with every
service, regardless of age or appearance.
▼ Refer to the schematic and parts list while performing
these procedures. Each part is identified by its reference
number shown on the drawing the first time it is referred
to in the procedure.
▼ Do not attempt to reuse parts that are designated to
be automatically discarded and replaced with the parts
provided in the overhaul parts kit. These parts should be
shown to the customer, however, to instill confidence that
complete overhaul service has been performed.
▼ Inspect all reusable parts as directed, either during or
immediately following the disassembly procedures. When
in doubt, compare the part with one that is new to best
determine its condition.
Copyright ©2011 XS Scuba
AltAir Octo
Second Stage Disassembly
CAUTION: Whenever possible, use only plastic or brass
O-ring tools for removing O-rings in order to prevent
damage to the sealing surface. Steel instruments, such
as dental picks, can easily damage the sealing surface
of a softer brass part, causing irreparable leakage and
requiring the part to be replaced with new.
1. Slide back the hose guard(25) to expose the connection
of the LP hose.
Fig. 1 – Removal of LP Hose
2. While holding the inlet fitting(22) secure with a w" openend wrench, apply a n" open-end wrench to the fitting of
the LP hose(26). Turn the fitting counter-clockwise to
loosen and remove. (See Fig. 1.)
3. Using a plastic or brass O-ring tool, carefully remove the
O-ring(27) from the post inside the hose fitting. (See Fig.
CAUTION: When performing the above step, be very
careful to avoid scratching the O-ring sealing surface.
Doing so may cause a permanent leak that will require
the replacement of the LP hose.
4. Snip the plastic tie-strap(6) that holds the mouthpiece(7),
and gently pull the mouthpiece off the second stage
housing(5). Inspect the mouthpiece to ensure that it is
supple and free of any tears or corrosion. If any damage
is found that could result in discomfort or leakage, discard
the mouthpiece and do not reuse.
5. Hold the diaphragm purge cover(2) lightly depressed,
and apply a a w" open end wrench to turn the inlet fitting
counter-clockwise until loose. Then, unscrew it completely by hand to remove.
6. Squeeze the O-ring(21) between thumb and forefinger to
remove it from the inlet fitting. Discard the O-ring and do
not reuse.
7. While holding the inlet fitting secure, apply a medium
blade screwdriver to the slotted head of the adjustable
orifice(23), and turn it counter-clockwise to disengage its
NOTE: The orifice is O-ring sealed, and it will remain
inside the lever support after it has been unthreaded.
The following step must be performed correctly in order
to remove the orifice without damaging its polished
sealing surface.
AltAir Octo Service and Repair Manual
Fig. 2 – Removal of LP Hose O-ring
Service & Repair Manual
8. When the orifice has been unthreaded from the inlet
fitting, carefully insert a small wooden or plastic dowel
through the opposite end of the valve body, directly over
the sealing edge of the orifice. Gently press out the orifice. (See Fig. 3.)
9. To avoid using a sharp tool that can damage the orifice,
squeeze the O-ring(24) between thumb and forefinger to
remove it from the orifice head. Discard the O-ring and
do not reuse.
Fig. 3 – Removal of Adjustable Orifice
10. Closely examine the orifice with the use of a magnifier,
checking for any scratches or other damage to the sealing
edge and the groove that holds the O-ring (see Fig. 4). If
any damage or wear is found, discard the orifice and do
not attempt to reuse. If it is in reusable condition, set it
aside on a soft surface to keep it isolated from other metal
11. While holding the second stage secure in one hand with
the purge facing up, firmly grasp the retaining ring(1) with
the other, and turn the ring counter-clockwise to loosen
and remove it.
Fig. 4 – Orifice Inspection
NOTE: If the retaining ring is difficult to loosen, XS
Scuba recommends using the Rim Clamp (P/N 20795-200), available from Peter Built Co. Complete
instructions are provided with the tool.
12. Lift off the diaphragm purge cover, and then gently pull
out the diaphragm(4) with the thrust washer(3). Closely
inspect these parts to ensure they are perfectly round and
free of any distortion, tears, or other damage. If any part
is found to be damaged, discard it and replace with new.
NOTE: Do not attempt to disassemble the anti-friction
disc from the center of the diaphragm.
Fig. 5 – Disassembly of Valve Mechanism
13. Through the inlet opening of the second stage housing,
gently press the lever support(17) with the complete valve
assembly into the second stage housing to remove.
14. Reassemble the inlet fitting with the lever support by hand
until finger snug, in order to hold the shaft of the poppet(19) in place without turning, inside the keyed (square)
hole of the lever support.
15. While holding the assembly secure, apply a 4" nut driver
to turn the locknut(14) counterclockwise until it is completely unthreaded from the poppet (see Fig. 5).
Discard the locknut and do not reuse. Remove the spacer(15)
Copyright ©2011 XS Scuba
AltAir Octo
and lever(16), and examine the lever to ensure that it is
not bent or damaged. Replace with new if any damage is
16. Disassemble the inlet fitting from the lever support, and
remove the poppet and low pressure spring(18). Closely
examine the spring under strong magnification to check
for any signs of corrosion, and replace with new if any
corrosion is found.
17. Using a sharp pick or straight pin, lightly pierce the center
of the LP seat(20) and remove from the poppet. Discard
the seat and do not reuse.
18. Examine the condition of the lever support and poppet
to check for any signs of thread damage, corrosion or
chrome loss. Replace with new if significant damage is
19. Remove the exhaust grill(9) from the second stage housing by inserting a small (.02mm) flat blade screwdriver
into both slots on either side of the second stage housing.
(See Fig. 6.) Gently pull the grill out of the housing, being
careful to avoid bending.
Fig. 6 – Exhaust Grill Removal
20. Remove and discard both of the exhaust valves(8) by
pulling each one straight out of the housing. Do not attempt to reuse.
21. If the male portion of the quick disconnect assembly(12)
is undamaged, no further disassembly is required. To
remove the QD clip from the second stage housing, follow
these steps (see Fig. 7):
a. Remove the small C-clip(13) from the underside of the
stainless steel post.
b.Tap out and remove the stainless steel post(11), and
pull the male clip away from the housing.
c.Examine the housing to check for any damage that
may impair a secure connection of the QD Clip. If found,
it will be necessary to replace the housing.
d.Reassemble the QD Clip in reverse order.
▼ After completing the disassembly of the second stage,
refer to the instructions provided in the XS Scuba Authorized Service Document, titled - Cleaning & Lubrication.
AltAir Octo Service and Repair Manual
Fig. 7 – Disassembly of QD Cllip
Service & Repair Manual
Reassembly Procedures
General Guidelines
▼ Refer to the schematic parts list, that highlights automatic
replacement parts which should be discarded and replaced
with new during reassembly. These parts are provided in the
Annual Service Kit.
Before performing any reassembly, it is important to individually inspect all parts, both new and those that are being reused,
to ensure that each part and component is perfectly clean and
free of any dust, decay, or blemishes.
If the regulator has been serviced for use with EAN/Nitrox, it is
important to don powderless latex gloves before handling any
parts, including O-rings, in order to avoid contaminating the
parts with skin oil.
Prior to dressing, inspect all O-rings with magnification to ensure they are supple, clean, and completely free of any scoring
or decay that would impair proper sealing.
XS Scuba recommends Christo-Lube® MCG-11 (PN MS150)
to be used exclusively for the lubrication and dressing of Orings and other internal parts. Christo-Lube® provides superior
lubrication to that of silicone grease, especially in high pressure
(DIN) systems greater than 3,000 psi, and extreme temperature conditions. It is also non-reactive to oxygen, and is approved for use with EAN/Nitrox.
CAUTION: Silicone grease is not compatible with oxygen
enriched air, and must be strictly avoided when servicing
a regulator that will be used with EAN/ Nitrox. The entire
regulator will otherwise become contaminated, and rendered unsafe for use with any mixture of oxygen enriched air.
▼ Dress all O-rings with a visible film of Christo-Lube, but avoid
applying excessive amounts, as this may attract particulate
matter that can cause accelerated wear or damage to the
CAUTION: The use of aerosol spray or petroleum based
lubricants must be strictly avoided. The propellant gas or
petroleum base may attack or weaken plastic or rubber
▼ Use all replacement parts provided in the XS Scuba Authorized
Dealer parts kit.
Copyright ©2011 XS Scuba
AltAir Octo
WARNING: DO NOT attempt to use any other manufacturer's part as a substitute for any XS Scuba part,
regardless of any similarity in shape, size, or appearance. Doing so may render the product unsafe, and
could result in serious injury or death.
1. Install both exhaust valves(8), if they were removed, into
the second stage housing(5) by gently pulling the stem
through the hole in the center of the sealing area, until the
barb has passed through and is securely seated against
the opposite side. Trim the excess stem material close to
the barb.
Fig. 8 – Exhaust Grille Installation
2. Fit two tabs on one side of the exhaust grill(9) into the
mating slots of the second stage housing, and then flex
it inward slightly to engage the tabs on the opposite side.
(See Fig. 8.)
3. Install a new LP seat(20) into the head of the poppet(19)
with the smooth side facing out, and press it into place so
that it is seated flush. DO NOT use adhesive.
4. Apply a light coat of lubricant to both ends of the LP
spring(18), and place the spring over the threaded shaft
of the poppet.
Fig. 9 – Correct Lever Orientation
5. Mate the squared poppet shaft through the lever support(17), and then fit the inlet fitting(22) over the poppet
head. Screw the inlet fitting clockwise into the lever support by hand, in order to hold the poppet shaft securely in
place without turning.
6. Place the lever(16) over the poppet shaft inside the flange
of the lever support as shown in Fig. 9, followed by the
7. Turn the locknut(14) clockwise by hand until the threads
are engaged by at least two turns. Apply a 4" nut driver
to turn the locknut clockwise until exactly two threads of
the poppet shaft are visible outside the locknut. (See Fig.
Fig. 10 – Valve Reassembly
8. Remove the inlet fitting from the lever support, and install
the O-ring(21) onto the groove of the inlet fitting above
the smaller section of threads.
9. Install the valve assembly into the second stage housing
with the lever facing up (see Fig. 11). While holding it securely in place, mate the inlet fitting through the opposite
side of the second stage housing, and turn clockwise by
hand until finger snug.
Fig. 11 – Installation of Inlet Fitting
AltAir Octo Service and Repair Manual
Service & Repair Manual
10. Apply an inch-lbs torque wrench with w" socket to tighten
the inlet fitting to a torque measurement of 90(±5) inchlbs.
11. Install the O-ring(24) onto the head of the orifice(23), and
insert the orifice into the open end of the inlet fitting with
the threaded end facing in. Apply a blunt probe, such as
a pencil or wooden dowel, to seat the orifice against the
threads inside the inlet coupling.
12. Apply a medium blade screwdriver to engage the slotted
head of the orifice, and turn it clockwise approximately 5
full revolutions. Then, grasp the screwdriver by the shaft,
rather than the handle, for best sensitivity of touch (see
Fig. 12). Continue turning the orifice very slowly while
closely observing the lever. STOP turning the orifice
when the lever begins to drop. This will indicate that the
orifice has made contact against the LP seat.
Fig. 12 – Preliminary Setting of Orifice
CAUTION: Do not continue to turn the orifice further
beyond the point where it makes contact with the
low pressure seat. Doing so may wear the LP seat or
sealing surface of the orifice, and can also result in an
incorrect adjustment of the second stage.
13. Lay the diaphragm(4) inside the second stage housing,
directly over the lever, with its raised surface facing up.
14. Fit the thrust washer(3) over the diaphragm and press it
into place so that it is seated at the base of the housing
threads on all sides.
15. Place the diaphragm purge cover(2) over the the diaphragm and thrust washer, followed by the retaining
ring(1). Turn the purge cover as needed to align the logo
straight between the mouthpiece and inlet, and hold in
place while tightening the retaining ring clockwise until
16. Install the mouthpiece(7) onto the mouthpiece tube of the
second stage housing. Fit a tie-strap(6) over the mouthpiece with the locking tab facing toward the retaining clip,
and cinch it snug. Snip off the excess strap that extends
outside the locking tab.
▼ After completing the reassembly of the second stage,
proceed to Section 5 – Final Testing
Copyright ©2011 XS Scuba
AltAir Octo
Final Testing Procedures
CAUTION: If the regulator will be used with EAN/ Nitrox,
it is important to pressurize and flow test the regulator
using only hydrocarbon-free gas. The regulator will
otherwise become contaminated with hydrocarbons
if normal compressed air is used. Industrial grade
compressed Nitrogen is strongly recommended as a
lower cost alternative to EAN/ Nitrox for the purposes
of flow testing.
1. Connect the IP Test Gauge onto the inlet fitting of the Inline Adjusting Tool and mate the opposite fitting of the tool
onto the inlet fitting of the second stage. Pull back the
knurled knob to retract the slotted drive, and tighten the
tool clockwise onto the inlet fitting only until finger snug.
(See Fig. 13.)
2. Install the O-ring(27) onto the post inside the female fitting
of the LP hose(26). Mate the female fitting of the LP hose
onto the male fitting of the IP Test Gauge, and tighten the
swivel nut clockwise until finger snug.
3. Install the O-ring(28) onto the male fitting of the LP hose,
and install the hose into an intermediate pressure port of
a first stage regulator that has been verified to be properly
serviced, with a stable intermediate pressure of 140 (±5)
psi . Apply a torque wrench with a crow-foot to tighten
the fitting to 38 (±2) inch-lbs.
CAUTION: If the second stage has been cleaned and
serviced for use with EAN/ Nitrox, it is important to connect it with a first stage that has also been cleaned and
serviced accordingly, and to use only hydrocarbon-free
gas while performing this procedure. Use of standard
compressed air will otherwise contaminate the system.
4. Ensure that all the first stage ports are sealed, and connect the first stage with a filtered gas supply of 2,5003,000 psi. Slowly pressurize the regulator. Listen to
verify that a leak can be heard from the second stage
valve, and proceed to step 5.
AltAir Octo Service and Repair Manual
Service & Repair Manual
a. If airflow cannot be heard, it will be necessary to initiate a slight leak between the orifice and poppet. Press
the knurled knob inward to engage the slotted drive of
the Inline Adjustment Tool with the head of the orifice
inside the inlet fitting. Then, turn the orifice slightly
counter-clockwise while lightly depressing the purge
cover to prevent wear on the seat. Do not adjust any
further than is needed to establish a slight leak.
NOTE: If more than a slight adjustment is required to
initiate a leak, it is important to check the adjustment of
the locknut on the poppet shaft to verify once again that
it is set correctly to its preliminary setting, as specified
in Step 8 of the Reassembly Procedure.
5. Hold the drive of the Inline Adjustment Tool engaged with
the orifice. While lightly depressing the purge cover, turn
the orifice slightly clockwise a very small fraction of a turn.
Pause after each adjustment to listen, and be careful to
avoid over-adjusting beyond the point that the leak has
stopped. When the leak has stopped, purge the second
stage several times to ensure that it does not return. Observe the IP Test Gauge while purging the second stage to
verify that it indicates a stable intermediate pressure after
each cycle, with no creep or fluctuation.
CAUTION: Over-adjustment of the orifice can cause
excessive spring load in the second stage valve, and
may impair the regulator’s performance.
6. While holding the second stage with the mouthpiece facing down, gently shake it up and down. Listen closely
to determine whether any movement of the lever can be
heard inside, indicating that the lever has dropped. If lever
movement cannot be detected, proceed to step 8. Otherwise, perform the following steps to raise the lever:
Fig. 13 – Inline Adjustment Tool w/ IP Gauge
a. Remove the retaining ring, purge cover, thrust washer
and diaphragm to expose the valve assembly.
b. Apply a 4" open-end wrench to turn the locknut clockwise a small fraction of a turn. Do not over-adjust,
since it is important to tighten the nut onto the poppet
only as far as necessary to remove lever slack.
c. Repeat the above step until lever slack is eliminated.
d. Reinstall the diaphragm, thrust washer, purge cover,
and retaining ring.
Copyright ©2011 XS Scuba
AltAir Octo
CAUTION: Over-adjustment of the locknut can cause
excessive spring load in the second stage valve, and
may impair the regulator’s performance. If leakage
returns after following the above steps, disassemble
the second stage valve assembly and repeat the above
procedure following a close inspection of the orifice
and LP seat and reassembly.
7. When the second stage is properly adjusted with no leaks
or lever slack, depressurize and purge the system to disconnect the LP hose.
8. If the inlet coupling was removed, apply a torque wrench
with w" socket to tighten it to a torque measurement of 90
inch-lbs (±5).
9. Reconnect the LP hose to the inlet coupling, and apply
a torque wrench with n" crow-foot to tighten the LP hose
fitting to 55(±5) inch-lbs.
Subjective Breathing Test
1. Connect the regulator to a cylinder containing 2,500 –
3,000 psi, and open the valve to pressurize the system.
2. Fully depress the second stage purge to ensure that an
adequate volume of air flows through the mouthpiece,
sufficient to clear the second stage. Then, breathe several times from the second stage.
NOTE: A properly serviced and adjusted regulator
should deliver air upon deep inhalation without excessive inhalation effort, freeflow, or vibration. When
exhaling, there should be no resistance or sticking of
the exhalation valve. If any of these problems occur,
refer to Table 2 - Troubleshooting.
Flowbench Testing (optional)
The Subjective Breathing Test, combined with the
Intermediate Pressure Test, will sufficiently verify the
regulator's performance in most circumstances. As an
additional test, a Magnahelic flowbench can be used to verify
the opening effort, which should not exceed 1.5 – 2.0 column
inches H2O.
AltAir Octo Service and Repair Manual
Service & Repair Manual
External Leak Test
After first stage reassembly and final adjustment of the
second stage has been completed, submerge the entire regulator in a test tank of clean water while pressurized with 2,5003000 psi. Observe any bubbles arising from the submerged
regulator over a one minute period. The recommended time
is necessary due to slower bubble formation that occurs in
smaller leaks. Disassemble the regulator at the source of the
leak to check sealing surfaces, assembly sequence and component positioning in order to correct the problem(s).
NOTE: The location of extremely small leaks can best be
detected by applying a soap solution to the leak area.
Before disassembling to correct any leaks, rinse the
entire regulator thoroughly with fresh water and blow
out all residual moisture with filtered, low-pressure (25
psi) test gas. Refer to the Troubleshooting Guide.
▼ When the second stage has been adjusted and tested
according to the prescribed procedures, close the cylinder
valve completely, and purge the second stage to depressurize the system. Loosen the yoke screw to remove the
first stage from the cylinder, and seal the dust cap over
the inlet fitting. Disinfect the mouthpiece, and dry the
regulator completely with a clean towel. This completes
the overhaul service procedures for the ALTAIR regulator.
Copyright ©2011 XS Scuba
AltAir Octo
Troubleshooting Guide
Second Stage
SymptomPossible CauseTreatment
Freeflow or leakage
1. Excessive intermediate pressure.
1. Refer to first stage troubleshooting
2. Damaged or worn LP seat.
2. Replace with new.
3. Damaged orifice sealing surface.
3. Replace with new.
4. Damaged orifice O-ring.
4. Replace with new.
5. Orifice incorrectly adjusted.
5. Reset to preliminary setting and readjust.
6. Poppet spring damaged.
6. Replace with new.
Excessive Inhalation Resistance 1. Insufficent intermediate pressure.
1. Refer to first stage troubleshooting
or Hesitation
2. Orifice incorrectly adjusted.
2. Reset to preliminary setting and readjust.
3. Lever is damaged.
Insufficient airflow when
purge is depressed
1. Lever is slack, or orifice incorrectly adjusted. 1. Reset to preliminary settings and readjust.
2. Lever is bent.
Water entering second stage
1. Exhaust valve diaphragm worn or damaged. 1. Replace with new.
2. Mouthpiece worn or damaged.
2. Replace with new.
AltAir Octo Service and Repair Manual
3. Replace with new.
2. Replace with new.
Service & Repair Manual
Service Kit
Part # RK4
Dealer 8.00
Part #
# Part #
Retaining Ring
Purge Cover
Lever Support
Thrust Washer
“No Bump” Tie Strap
Exhaust Valve
Inlet Fitting
Exhaust Grill 3.00
Adjustable Orifice
Female Buckle Assembly
Attachment Post
Hose Guard
Male Buckle
LP Hose - 36” Yellow
13 14
20 21 24 27 28
Service Notes:
Adjust with intermediate pressure
125 to 140 psi
Lightly lubricate with Christo-Lube
MCG-111 part number TL108
Tighten nut until two full threads show
Protect the sealing edge of the orifice from
Remove o-rings without damaging parts
using brass pick part number TL111
* Bold Indicates Overhaul Replacement Part - Provided In Parts Kit #RK4
Copyright ©2011 XS Scuba
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