Si Tech Skeleton User manual

Photo: Jonas Wall
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Valve Manual
For optimal buoyancy control

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1. Optimal Buoyancy Control
Before early 70´s, drysuits was mainly used in commercial and military
diving activities. To avoid discomfort created by squeeze at greater depth,
overpressure valves were installed in the ankles, wrists and neck in order to
remove excessive air inflated through the face mask.
The inflation of gas also increased the undergarments insulation ability. This type of
drysuit was named constant volume drysuit. The wetsuit was a great improvement
and started to be popular in the early 50´s and drysuits in general became out aged.
Stig Insulán made his military service as a mine clearance diver. Stig was early invol-
ved in wetsuit and general diving gear manufacturing, which he started in 1962.
With his dedication to diving and interest in design he tested the ideas during com-
mercial diving operations. During long dives under ice in cold water Stig required
something better.
Stig´s invention of the variable volume drysuit valve, opened up for a new era of
underwater comfort. From extensive diving experience and expertise in regards to
diving physiology a number of criterias was set up:
1. It must act as an automatic overpressure valve, also at maximum setting.
2. It must have feature for manual dumping of insulation gas with occupied hands.
3. It must have a sensitive regulation of internal suit pressure.
4. It must at a given setting maintain internal gas for buoyancy control.
5. It must maintain insulation and flotation gas for prolonged surface time.
6. It must be placed on a location allowing easy gas dumping without
inadvertently deflation. E.G Rising hands for alert call.
7. It must have adequate flow rate to enable easy ascent speed control.
8. It must be removable for checking and service.
9. It must be attached in a Valve Port, preventing leakage if material is compressed.
Also to avoid rip out if tangled.
The result of Stig´s and SI TECH´s efforts is known worldwide and has
evolved modern drysuit diving to what it is today!
SI TECH Valves are designed to make your dives pleasant and easy
avoiding dangerous pressure gradients between the suits inner
and outer pressure with a maximum resistance of 25 mbar.
The focus of the valves is the pressure precision that make the SI TECH
valve superior. This also assures to prevent leakage of insulating gas
when set to maximum pressure for extended surface buoyancy and
warmth. The location of the Exhaust Valve at the upper arm ensure
an easy access of internal gas venting when controlling ascent
speed and fine adjustment of buoyancy during the dive. At minimum
setting 2 mbar the suit can be evacuated to a minimum of free
gas (not gas inherent in the underwear).
For secure attachment the valve is preferably attached with SI TECH
Valve Ports. This allows you to make service an easy task.
Basic diving physiology helps you to understand
buoyancy control!
To easier determine your buoyancy, reduce number of gas filled compart-
ments. The gas in the suit is the main compartment for a good insulation.
By utilizing the valve in an optimal way you also control your buoyancy with
the amount of gas in the suit. In a stressed situation it can be difficult to
determine which compartment to manouver if the BCD* is simultaneously
used. Also consider buoyancy change in a thick neoprene drysuit. Gas volu-
me changes in regards to depth. The weight of gas in your cylinder changes
during the dive and must be considered when determining your weighting
for a optimal buoyancy control at the end of dive. A weight loss of roughly
3 kg (6 lbs) has to be considered from start to end of dive.
*BCD = Buoyancy Control Device

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2. Basic construction 3. Mounting
(+)
•Hold the protection ring in a firm grip, turn the attachment nut on the inside of the drysuit by hand until
you feel its firmly tightened. The Anti-friction washer should always be used, positioned between the
suit and the nut. •Use the attachment tools when applying torque. Be sure that the valve is settled
correctly into the guide ridge of the Valve Port.
Do not hold the cover on the
Exhaust Valve when mounting or
detaching!
Over tightening may destroy the
valve! Please use the attachment tools.
NEVER use the cover/lid to tighten the valve. Do not
mix the Exhaust and Inflation attachment nuts when
re-fitting the valves. Note that the Exhaust Valve
attachment nut has a filter! If the valve is impossible
to detach, although using the appropriate tools
correctly, contact your dealer.
Hold the protection ring in
a firm grip!
...turn the
attachment nut
on the inside...
...Anti-friction
washer shall
always be
used...
...match the
notches on
the tools to
the barbs on
the valves.
DO NOT OVER TIGHTEN
THE VALVE!
This might cause damage to
the drysuit and/or the valve.
If you have any doubts, please
contact a qualified technician.
Usage of attachment tools!
These instructions cover drysuits equipped with SI TECH Valve Ports,
ensuring a safe and tight fitting according to standard requirement.
•Prior to detachment from the suit and prior to re-attachment into
the suit Valve Port, make sure that the Exhaust Valve cover is
adjusted clockwise to full stop (+).
Incorrect Correct
2
3
4
5
6
1 7
8
9
10
11
12
13
1. Cover/lid
2. Adjustment ring
3. Center guide
4. Protecting ring
5. Anti-friction washer
6. Attachment nut & filter lid
7. Adjustment lid
1. Cover/lid
2. House (rotating)
3. Tongue
4. Opening connector
5. O-ring
6. Stem piston
7. Push button
8. Retainer
9. Piston
10. Membrane
11. Guide sleeve
12. Filter
13. Check valve
8. O-rings
9. O-ring
10. Lock ring
11. Anti-friction washer
12. Attachment nut
Exhaust Valve
Inflation Valve
2
3
4
5
6
1 7
8
9
10
12
11
SI TECH Inflation Valves include valves operated
by push or slide button. The capacity and
function of the valves are the same.
Operated by
Push button
Operated by Slide button
SI TECH Exhaust Valves are designed to be set for
automatic buoyancy control. A ratchet function provi-
des the opportunity to fine tune the release of gas!
Cejn
Quick-On
Quick-OnInt´l
Quick-On
BasicInt´l Int´l
Variations
Connectors and Hoses
Cejn Int´l Int´l
SI TECH Inflation Valves can be delivered with either Cejn or Int´l connector (Slide Inflation Valve is only
available with Int´l). There are also the opportunity of choosing between a ”Quick-On” hose connector
or a basic version operated manually. The ”Quick-On” locks when pushed on to the male connector of
the valve. Hoses and connectors shall be inspected annually.

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4. Operating SI TECH Valves
SI TECH Exhaust Valves are very sensitive to small variations in the difference between internal and
external pressure. The Exhaust Valve is adjustable between 10-200 mm column of water (1/2 to 8
inches) to provide buoyancy variation with the inherent gas volume.
Easy adjustment of the gas volume in the drysuit is hereby simplified and the drysuit may
be used as the only method of buoyancy control during normal diving conditions (BCD emptied
of gas during the dive). This will also support a controlled ascent, approx. 10-18 meters/minute
(35-60 feet/minute), provided the diver’s buoyancy is correctly compensated and the valve is set
properly.
Set the Exhaust Valve for automatic buoyancy control
You can remain neutrally buoyant without manual deflation; when the Exhaust Valve is correctly
located (on the highest point of the drysuit, most commonly on the left upper arm) and
properly set, and when you are correctly compensated with weights. When you adjust the
setting by turning the valve cover, a clicking sound will help you determine the fine tuning.
When the valve is properly set you will be able to fine tune the gas volume in the drysuit
further by rolling the body or by raising or lowering the elbow.
The valve may need further fine tuning during the dive depending on gas consumption during dive
and the suit material. There should be no gas in your BCD during the dive. The BCD is used only
as a back-up. Adjust the valve slightly by turning the valve cover. The clicking sound that
can be heard when you turn the valve cover makes it easy for you to fine tune the valve while diving.
The symbols + and – above the logo label on the lid indicates the effect.
For reduced buoyancy (red):
adjust counter clockwise (towards-)
= lower pressure = less gas
retained in the suit.
For increased buoyancy (blue):
adjust clockwise (towards+)
= higher pressure in the suit
compared to ambient water
pressure = more gas retained in the suit.
Manual deflation
If the pressure setting of the valve
is high (clockwise, to +), press any-
where on the valve lid to override
this setting and to deflate gas. How-
ever, the valve is normally operated
by minor pressure changes.
Factors that need to be considered if the deflation capacity of the Exhaust Valve seems
inadequate are: the valve location on the suit, the suit fit (too much volume above the shoulders
could lead to a pocket of gas being trapped above the valve), the permeability of the underwear and
insufficient weight compensation.
For further information, please contact your local SI TECH dealer!

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6. Warnings & Recommendations5. Maintenance
Both valves should be checked/serviced annually by a SI TECH approved service center.
Inflation Valve
•Avoid exposing the quick connector socket on both valve and hose to water and sand.
Use the protective cap when the hose is not attached.
•Rinse the drysuit and Inflator Valve with fresh water after every dive. After rinsing, attach the hose
and purge air through the valve until clean and dry. If the action of the inflate button becomes stiff,
spray a suitable silicone based spray into the quick connect socket and work the push/slide button.
Exhaust Valve
•After each dive, especially if water contains debris and sand, flush the Exhaust Valve thoroughly with
fresh water while turning the cover/lid back and forth. Make sure the valve is empty from water
when diving in cold conditions.
•The Exhaust Valves is equipped with a filter, that prevents lint from your undergarments getting stuck
in the check valve which could cause the valve to leak. Flush the filter through the attachment nut.
Before each dive, check that the ratchet action of the lid feels distinct. Old models of SI TECH
valves might be without ratchet action.
•Before donning your drysuit – check that the valves are properly fitted.
•SI TECH AB recommends you to limit drysuit compartments that can trap and contain gases
which could cause buoyancy control problems. This means that the BCD should normally not
be used for buoyancy control during the dive.
•A tightly fitting suit, belt or other equipment may restrict the flow of gas within the suit
causing reduced deflation capacity of the Exhaust Valve. A non-restrictive-fit is desirable, but
the suit must not be too large, especially not over the shoulder area .
•Be sure that the neck seal is properly trimmed and folded for comfortable fit. A neck seal that
is too tight can restrict the flow of blood to and from the brain. A neck seal that is too loose
will allow gas to leak out and cause a reduction of pressure within the suit that will have a
negative effect on the Exhaust Valve’s capacity to provide automatic buoyancy control.
Remember to squeeze the drysuit before entering the water feet first. If not, you may
risk the neck seal turning inside out.
•Differing compositions and physical properties of various drysuit undergarments affect
the flow of gas through to the exhaust valve.
•While diving, avoid inflating when your feet are above your head.
•Using yourself and your drysuit as a lift bag will put your life in danger. For the same reason,
never attach a lift bag to your Drysuit or BCD Hose.
•If you are unfamiliar to diving with a drysuit tell your dive buddy and/or your dive master.
Allow yourself time to get familiar with the characteristics of your drysuit.
•Diving can be a potentially dangerous activity. Stressed divers can make decisions that may
prove fatal. Dive within your physical, mental and experience limitations. Get to know your
equipment and practice in a comfortable environment. Your personal fitness, experience,
knowledge and judgment are factors that will be crucial for your ability to handle a crisis
situation. Give up diving for the day if you are not feeling well or if you do not feel comfortable
with the dive situation, your own ability or equipment. Always perform a pre-dive check on all
your diving equipment and correct any malfunctions before diving.
All diving is done at your own risk.

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SI TECH Drysuit Valves
Warranty:
SI TECH warrants to the original purchaser, their valves and hoses to be free of defects in material or workmanship for a period of
thirty six (36) months from the date of purchase, to a maximum of sixty (60) months from the date of manufacture. Comments or
questions about this warranty should be directed to [email protected]. Please include information about the batch code, brand and
model of drysuit, serial numbers and proof of purchase. SI TECH AB will provide further information about where to send the product.
Limitations in warranty:
This warranty will be considered null and void when damages are caused by misuse or abuse such as, but not limited to, impact damage,
unauthorized repair or modification, chemical or gas exposure, temperatures in excess of 175 degrees F (*80 degrees C). Products with
altered or removed identification numbers are not covered. This warranty does not cover parts
normally found in SI TECH service kits, such as O-rings, gaskets, seats, etc.
Manufactured in Sweden
Quality Approved Worldwide
Exhaust ValvesInflation Valves
Skeleton
Shell
Slide
- Slide activated sideways
- Rotating 360° degrees
- Anti-friction washer
- Nipple cover
- Available with Int´l coupling
- High or low push button
- Rotating 360° degrees
- Anti-friction washer
- Nipple cover
- Available with Int´l or Cejn coupling
- High or low push button
- Rotating 360° degrees
- Anti-friction washer
- Nipple cover
- Available with Int´l or Cejn coupling
- Ratchet action
- Adequate flow performance
- Easy manouvering
- Safety Valve
- Ratchet action
- Adequate flow performance
- Easy manouvering
- Safety Valve
- Great when using heavy duty gloves
- Ratchet action
- Adequate flow performance
- Easy manouvering
- Safety Valve
- Great when using heavy duty gloves
Thetis
Argo
Gaude
Dump Valves Our complete range of valves does also
include Dump Valves for a variety of needs.
These can be found at: www.sitech.com
This manual cover standard valves and hoses. Custom made valves and hoses may differ in use and
procedures. SI TECH reserves the right to incorporate modifications in products without any notice. SI TECH reserves
the right for misprints. Images and illustrations are protected according to copyright regulations.
SI TECH is a Swedish company focusing on development,
manufacturing and marketing of innovative safety solutions
for protective suits such as; drysuits, rescue suits and similar
protective garments. SI TECH is rooted in the diving industry
and this is still the company’s core market. The company
was founded in 1971 by innovative diving pioneer Stig Insulán.
Core products:
Modular Quick Change Solutions, Drysuit Valves, Seals,
Dry Glove Systems, Gas Supply Systems.
Market Segmentation
Marine | Military | Rescue
Development & Production
We take pride in the statement ”Made in Sweden”! At SI TECH
we are running both development and production in-house at our
facilities in Brastad. Inhouse competencies include: CAD construction,
Injection Molding, CNC Machining, EMD Machining, Assembly, Sales
and Marketing, Logistics and Administration. Our team of engineers,
sales and marketing personell have a close co-operation with the
end-users of our products. Our location close to the ocean provides us
with fantastic opportunities of testing our products in situations from
normal to extremes.
Sales & Marketing
Company sales and marketing is operated from company headquarters
in Brastad, Sweden. On the international arena SI TECH is guiding a
network of distributors operating on a worldwide basis.

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SI TECH AB 2013 | Valve manual | Version: 4.0 | May 20, 2013
Thank you for choosing a drysuit equipped with valves from SI TECH,
the No. 1 choice of discerning divers! SI TECH valves are designed to
meet the highest standards of comfort and safety!
I strive to keep it that way and wish you many pleasant dives.
Jonas Axelsson, President of SI TECH AB