SCUBAPRO-UWATEC MK17 Manual

MK17 revision may 2005 1 / 1
MAINTENANCE PROCEDURE FOR MK17

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MAINTENANCE PROCEDURE FOR MK 17 1ST STAGE
WARNING: this maintenance procedure is only for appointed Scubapro technicians
that followed a complete course on equipment repair and in no case can replace a
technical repair course delivered by an appointed SCUBAPRO/ UWATEC appointed
staff.
Tools needed:
1. universal tool P/N 43.040.000
2. socket P/N 43.191.107
3. socket extension P/N 43.300.009
4. field handle tool P/N 43.300.127
5. o-ring extractor P/N 43.300.107
6. filter retainer mounting tool P/N 43.026.101
7. balance chamber tool P/N 43.300.240
8. torque wrench P/N 43.300.988
9. 2nd stage adjustment tool P/N 41.043.000
10. 1st stage chamber tool P/N 43.300.999
11. Scubapro blow gun P/N 40.978.000
12. interstage pressure gauge
13. 4 mm Allen key
14. 6 mm Allen key
15. screwdriver
16. 32 mm spanner or large adjustable wrench
17. work bench with vice
DISASSEMBLY
1. Unscrew all hoses from the 1st stage with the universal tool being careful not to dam-
age the chrome plating. Remove all the plugs from the 1st stage with the 4 mm Allen
key or with the universal tool. Remove the o rings from the plugs with the o ring ex-
tractor tool and inspect.
2. Remove the inlet protector.
3. Remove carefully the 2 rubber bumpers with the screwdriver.
4. Take the field handle tool and use preferably for strength the bigger thread 7/16" and
screw it in one of the HP ports.
For the INT version: Remove the yoke screw, then firmly hold the field handle tool
fixed to the body of the 1st stage in the vice and use the socket and socket extension
to carefully remove the yoke retainer. Remove the yoke and saddle. Remove the fil-
ter retainer with the screwdriver, the filter and the o ring with the o ring remover. Put
aside the o ring (01.050.138) for inspection.

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For the DIN version: Remove with the o ring extractor the "tank" o ring, then with the
4 mm Allen key unscrew the filter retainer. Remove the spring and the filter. Firmly
hold the field handle tool in the vice and use the 6 mm socket extension to unscrew
with care the DIN knob retainer. Remove the o-ring and the knob. Put aside the o
ring (01.050.138) for inspection.
5. Remove the bumper cap on the fins side with the small screwdriver.
6 Unscrew with the multifunction or 1st stage chamber tool the diaphragm retainer.
Carefully remove the washer, the silicone diaphragm and the load transmitter.
7 Unscrew the spring adjustment screw with the 6 mm. Allen key. Remove the nylon
washer in the spring adjustment screw and the spring.
Note! : The diaphragm disc will not come out trough the spring adjustment screw
hole.
8 With the 32 mm spanner or the adjustable spanner, unscrew carefully the dry ambi-
ent chamber, remove the diaphragm disc and the 2 washers with the o ring extrac-
tor.
9 With the o ring extractor carefully remove the diaphragm, the thrust disc, the metal
disc insert and the pin.
10. Remove the bumper cap on the Allen key side of the 1st stage with the small
screwdriver.
11.Unscrew the balance chamber with the 6 mm Allen key. Remove the 2 balance
chamber o rings on the outside, the spring, the spring centring washer, the balance
chamber o ring and the bushing ring from the inside.
11.Remove the spacer, the guide from the HP poppet.
12.Use the MK 16 tool and lightly push the tool against the orifice while blowing into
the 1st stage body from the opposite side (diaphragm side) with the blowgun to
carefully remove the orifice. With the o ring extractor tool, remove the o ring from
the orifice.
13.Remove the field handle tool.
PARTS CLEANING
WARNING: refer to parts cleaning procedure.

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ASSEMBLY
After careful inspection of the cleaned parts and the static o rings that do not need re-
placement, prepare all the parts that need to be changed at every annual service.
a. the filter 01.028.109
b. the filter retaining clip ( only for INT version) 01.073.101
c. the HP seat 10.117.103
d. the poppet balancing o ring 01.050.117
e. the balance chamber o ring 01.050.145
f. or the repair kit for MK 17 10.117.040
1. For the INT version: insert the filter in the yoke retainer and then fit the filter retainer
with the filter retainer tool. Fit the o ring 01.050.138 in its cavity. Slightly grease the
threads of the yoke retainer and the o ring before inserting in the yoke and the sad-
dle.
Firmly hold the 1st stage body with the field handle tool screwed in a HP port and
fixed in a vice. Place the socket on the yoke retaining screw, and the socket exten-
sion on the torque wrench.
Adjust the torque wrench to 30 Newton meter and tighten. Never use a torque
exceeding 30 Newton meter.
For the DIN version, assemble the o ring 01.050.138 in its cavity, slightly grease the
threads and the o ring before inserting in the DIN wheel. Place the wheel retaining o-
ring and the saddle. Only use the 6 mm socket extension for tightening
Adjust the torque wrench to 30 Newton meter and tighten. Never use a torque
exceeding 30 Newton meter.
Now place the conical filter upside down (the tip of the filter facing the tank valve),
then the spring, slightly grease the threads before screwing the filter retainer with a 4
mm allen key to 4 Newton meter torque. Insert the “tank" o ring
WARNING: The use of a torque wrench is highly recommended, if unavailable,
for a torque of 30 Newton meter, screw hand tight, then use a wrench and
tighten 1/8 of a turn!!! An excess torque can lead to a permanent deformation
or even a rupture of the parts.
2. Place the o ring on the orifice and insert this assembly inside the body of the 1st
stage taking care to guide its way in with the MK16 tool. Press the orifice slightly
down in the chamber with the tool.
3. Slightly grease the bushing, the o-ring and centring washer and place the 3 parts in-
side the balance chamber.
4. Slightly grease the 2 o-rings and thread of the balance chamber and place the 2 o
rings on the balance chamber.
5. Slide the spacer and guide on the HP-poppet. Slightly grease the shaft of the HP-
poppet before inserting the spring.

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6. Insert the assembled HP-poppet inside the assembled balance chamber.
7. Insert the whole system inside the 1st stage and screw snug with the 6 mm Allen key.
Warning ! : Do not over torque.
8. Place the diaphragm pin in the HP-poppet followed by the metal disc insert and the
disc.
At this stage it is possible to check the perfect seal between the HP seat and
orifice.
9. Remove the field handle tool from the HP-port, reassemble the HP-plugs, slightly
grease the o-rings and threads and replace them in the body. Do not over torque (4
to 5 Newton meter maximum)
10. Connect the 1st stage to a tank, filled to the working pressure of the 1st stage and
carefully open the tank valve.
Once pressurised, there should be no leak. A slight push with the thumb on the
disk opens the system and air will flow. It is advisable to cycle the system a
few times to check the air lock. Purge the system before removing the 1st stage
from the tank.
11. Place the diaphragm in position, (WARNING: the diaphragm should always be dry,
no grease should be used for assembly) then the 2 diaphragm rings.
12. Place and centre the diaphragm disc on the diaphragm.
13. Lubricate slightly the threads before screwing the dry ambient chamber by hand in
the body.
14. Fix the field handle tool again in one of the HP ports and secure the tool in a vice.
Use the 32 mm spanner or adjustable spanner and tighten snug the dry ambient
chamber on the body
WARNING: If the diaphragm is not properly secured by a firm tightening, there
is a risk of the diaphragm coming off its groove resulting in a heavy air leak
that could endanger the diver's life.
15. Slightly grease the threads of the spring adjustment screw and the spring groove be-
fore placing the washer.
16. Place the spring in the cavity of the diaphragm disk.
17. Screw the spring adjustment screw in the dry ambient chamber by about 2 / 3 turns.
18. Reassemble all the plugs and / or the hoses after having slightly greased the threads.
Do not over torque (4 to 5 Newton meter maximum )
19. Place back the 2 bumper caps.

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Attention! : Place the 2nd stage and the octopus to the HI FLOW ports on the body.

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THE 1ST STAGE IS NOW READY FOR THE ADJUSTMENT PHASE.
ADJUSTMENT
FOR THE ADJUSTMENT, IT IS VERY IMPORTANT TO HAVE A SUPPLY PRESSURE
CURRENTLY USED FOR DIVING WITH THE REGULATOR CONCERNED ( 200, 230 or
300 bars ).
1. Place the 1st stage on a full tank as previously indicated.
2. Place a precise interstage pressure gauge either at one of the interstage pressure
ports or at the end of the regulator hose
Warning ! : The gauge found on the adjustment tool is not precise enough because
of it's small size and should not be used as a workshop gauge. A bigger size and
more precise gauge should be used in a repair workshop.
3. Slowly open the tank valve.
4. Observe carefully the needle of the gauge that should move in a very smooth way
before coming to a sharp stop. Cycle the regulator about 10 times by purging the 2nd
stage. This is to allow all the moving internal parts to reach their permanent working
position.
5. Take note of the interstage pressure when the needle of the gauge comes to a stop.
Three cases can occur:
the interstage pressure is in between 9 and 10 bars
the interstage pressure is lower than 9 bars
the interstage pressure is higher than 10 bars
6. If the gauge indicates an interstage pressure between 9 and 10 bars with a good sta-
bility of the needle of the gauge, a good adjustment has been reached.
7. If the interstage pressure is less than 9 bars, use a 6 mm Allen key to slowly screw
(clockwise) the adjustment screw. Every time the adjustment screw is turned, the
regulator should be cycled about 10 times before a reading of the interstage pressure
is taken. Proceed by 1/4 turn to reach the correct setting which should be in between
9 and 10 bars.
8. If the interstage pressure is higher than 10 bars, proceed as above but unscrew (an-
ticlockwise) the adjustment screw to reach the correct setting.
9. If after several unsuccessful attempts in reaching a stable interstage pressure,
change the diaphragm.
Note: As we previously carried out the leak test between the HP orifice and
seat, a bad interstage pressure lock does not come from these parts. A distort-
ed diaphragm is often responsible for a poor interstage pressure lock!!!

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10. Now fit the load transmitter through the spring adjustment screw and place the sili-
cone diaphragm and the washer. Slightly lubricate the threads of the retainer ring and
tighten with the universal tool.
Note: Placing the silicone diaphragm should be carried out only when the 1st
stage is still pressurised. Not doing so will trap air inside the dry chamber and
cause a slight overpressure thus affecting the stability of the interstage pres-
sure.
11. Close the tank valve and remove the 1st stage from the tank.
12. Place back the rubber bumpers and the inlet protector.