Regulators
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S.E.A. -Sequential Exhaust Assist [PAT.P.] (RS-681[S-81], SS-81)
The Sequential Exhaust Assist (S.E.A.) is an auxiliary exhaust valve, located on top of the
S-81 and SS-81 elliptical case that reduces primary exhaust resistance and significantly
decreases workload,
thus allowing the diver to be more air efficient.
SECTION III
PRE-DIVE PROCEDURES
WARNING
Do not attempt to connect low pressure hoses to the high pressure ports with the use of
an adapter. Improper connection will cause damage to the equipment and could result in
serious personal injury. Low pressure components are not intended to withstand pressures
greater than 400PSI ≈ (28bar) When installing your accessory hoses, avoid damaging the
O-ring. Tighten gently, but firmly into the first stage housing.
PRE-DIVE OPERATING INSTRUCTIONS
1. Position the tank valve so the outlet points toward the diver.
2. Remove the dust cap from the first stage inlet and place the yoke in the center of the
cylinder valve connection.
3. Position the first stage body so that the second stage hose goes over the right shoulder of
the diver.
4. Hand-tighten the yoke screw.
5. Check all the hose connections to the first and second stages. If they can be loosened by
hand, they should be tightened with a wrench before pressurizing.
6. Check the submersible pressure gauge to make sure it indicates zero pressure.
7. Open the tank valve slowly to gradually allow air into the regulator.
NOTE: During this operation, depress the second stage purge button to reduce shock to
the valve mechanism. Do not perform this operation in a cold environment below 50˚F(10˚C).
Performing this in a cold environment may cause“freeze-up”of the regulator which can lead it
to free flow. If this occurs, you should contact a TUSA authorized service center.
8. Check the submersible pressure gauge to ensure that it indicates the proper tank pressure.
9. Check the tank/regulator connection for leakage. If leakage exists, it may be caused by
incorrect mounting of the regulator on the tank valve, or by a damaged O-ring in the tank valve.
10. To confirm that the regulator delivers air properly, first exhale through the mouthpiece to
blow any foreign matter out of the second stage, then inhale. A few of these breathing
cycles should immediately indicate proper function.
11. If you are using the second stage as an Octopus regulator, it is strongly recom- mended
to utilize an Octopus plug to prevent any foreign matter from entering the second stage
through the mouthpiece.
12. When the second stage is not in your mouth, uncontrolled air delivery can take place. This
can be stopped by turning the second stage upside down and allowing it to fill with water.
Should the air delivery continue, abort the dive and have the regulator inspected by a TUSA
Authorized Service Center.
Regulators
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SECTION VII
SCHEDULED MAINTENANCE
1. Do not assume that a regulator is in good working order because of storage or infrequent
use. Prolonged or improper storage can still result in internal corrosion and/or deterioration
of O-ring seals.
2. 2. Have your regulator cleaned and adjusted frequently. The frequency will depend upon
the amount of use given the regulator and the conditions of use. However, TUSA strongly
recommends inspection, overhaul and scheduled parts replacement at least once a year in
order to ensure the optimum functioning of the regulator. Certain parts require replacement
at specific intervals. This work must be carried out by a certified TUSA repair facility.
Freguent use such as rental equipment and/or in salt, chlorinated (swimming pool), or
polluted fresh water might require cleaning and overhaul of the regulator every three to six
months. Chlorinated water is an especially bad environment for regulators as the chlorine
chemically deteriorates the neoprene rubber components.
3. Regularly inspect the sintered filter in the inlet port of the first-stage. If it is discolored
or corroded, replacement by trained personnel is required. Also, at this point, the entire
regulator may need a general overhaul with replacement of all soft seals and non-reusable
components. Rust or aluminium oxide (grey powder) deposits on the sintered filter are
usually an indication that salt water has entered the air cylinder and caused internal
corrosion. At this time you air cylinder(s) should be internally inspected by a qualified and
competent service control facility and then cleaned, or hydrostatically tested as required.
4. Do not disassemble your regulator. There are no adjustments which can or need to be
carried out by the user. Take the regulator to a qualified TUSA dealer or service facility for
service. Ensure that only original parts are used to service your regulator.
FINAL NOTE
Frequently service your regulator, your personal safety and the mechanical integrity of
your regulator depend on it.
Regulators
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2.1 FIRST STAGE
R-600 first stage
With the R-600, offers a compact design weight of just 630g during actual use. This allows
the R-671 to only be a total weight of just 955g for the first and second stages. The balanced
diaphragm method first stage features minimum variation in intermediate pressure in response
to changes in residual cylinder pressure and depth. The ports are in left-right symmetry (H.P.×
2, L.P. × 4) for easier attachment to tanks, even for beginners. The R-600 always supplies the
diver with stable air at any tank pressure or depth, delivering maximum breathing ease and
comfort for them.
R1100 First stage
The TUSA R1100 offers a first stage with the balanced diaphragm design. This design features
minimum variation in intermediate pressure in response to changes in residual cylinder pressure
and depth. The ports are in left-right symmetry (H.P. × 2, L.P. × 4) for easier attachment to
tanks, even for beginners.
2.2 SECOND STAGE
Demand system
The demand system is designed to significantly reduce rubbing resistance of moving parts
and air resistance. The result is smoother and more natural valve opening/closing. Lightweight
housing The second stage main unit is smaller and lighter to reduce water resistance during
diving, thus reducing the load on the face during use. The body materials are thermo plastic
resin reinforced with glass fiber for outstanding hardness and shock resistance. The materials
also offer superior tensile strength, dimensional stability, heat resistance, weather resistance
and chemical resistance.
Intake resistance
The second stage includes a director to forcibly guide air from the demand valve. That prevents
free flow while significantly lessening intake resistance. The result is one of the lightest
intake resistance values in the industry compared with products from other companies.
New mouthpiece
The new mouthpiece, developed on the basis of ergonomic engineering, further enhances the
comfort of bite, fit, and stability. Even with a light bite, a high level of stability is achieved, so
there is no fatigue from long periods of usage.
Venturi Adjustment Lever(RS-681[S-81], SS-81)
The addition of a venturi adjustment lever on the S-81 allows the regulator to power assist the
diver when underwater utilizing the natural venture effect to turn the adjustment to “DIVE”.
The diver can also adjust the lever to prevent free flow such as on a surface swim to turn the
adjustment to the other side.
Adjustment knob(RS-681[S-81], 671, 606, 1104, SS-81)
The adjustment knob also introduces a TUSA innovation, an“Easy touch”adjustment of the
breathing resistance at need. Ten full turns provides smooth, accurate adjustment for effortless
breathing.
Regulators
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SECTION IV
POST-DIVE PROCEDURES
Providing the best possible preventative and routine maintenance before, after, and between
dives will help to ensure the maximum life of your TUSA Regulator. To achieve this goal, there
are a number of simple, yet important, routine maintenance procedures that should be
followed by the diver after each use of the equipment. The following procedures should be
diligently followed in order to obtain the maximum life and serviceability from your regulator.
1. After each day of diving, the regulator must be cleaned, inspected, and prepared for the
next use, or for storage. As soon as the regulator is removed from the air cylinder, reinstall
the dust cap over the regulator inlet port. This cap is normally attached to the First Stage
and therefore has been under water. Be sure to dry all the water out of this cap before
securing it over the inlet port. Ensure that the O-ring, if fitted, is in place inside the dust cap.
2. 2. After diving, the regulator should be soaked in warm, not over 122˚F (50˚C) water to
remove salt and mineral deposits as soon as possible. The preferred method is to attach
the regulator to a charged air cylinder, open the cylinder valve, and thoroughly soak both
the first and second stage regulators . Pay particular attention to directing water into the
mainspring cavity of the first stage regulator, the second stage mouthpiece, and the holes
in the second stage cover. Depress the purge button several times while the regulator is
submerged in water. Dry the regulator by pressing on the purge button with the mouthpiece
pointing down. Place the dust cap in position in the yoke, or over the DIN screw. Soaking
regulator parts in warm water will remove more salt and mineral deposits than will
conventional rinsing. It will loosen deposits on interior components that rinsing will not (If
no charged air cylinder is available, follow the above procedure but be very careful NOT to
depress the purge button, or leave dust cap off, when the regulator is submerged in water.
Failure to do this will allow water to enter both regulator stages and may result in internal
corrosion). Simply soak the entire exterior of the first stage thoroughly, and proceed as
above when cleaning the second stage.
3. Store in a clean equipment box, or as an alternative, seal inside a plastic bag. Store in a
clean dry place.
4. Never store the regulator while it is still connected to the diving cylinder.
5. Do not use any type of solvent to clean any part of the regulator. Do not expose any part of
the regulator to silicone spray, as some aerosol propellants attack or degrade rubber and
plastic material.
6. Do not carry the diving cylinder by the regulator as such abuse will eventually damage
the regulator or the cylinder valve. Do not expose the regulator to unnecessary shocks or
impact.
SECTION V
CONTAMINATED WATER DIVING
Sophisticated diving gear designed for use in contaminated water provides constant positive
pressure inside the regulator case and utilizes redundant exhaust valve passages. TUSA
regulators are not designed to provide this requirement and therefore are not recommended for
use in contaminated water diving.
