Kirby Morgan 455 User manual

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-1
455 Balanced Regulator General
455 Balanced Regulator
Contents
455BAL-1 1.1 General
455BAL-1 1.2 455 Balanced Regulator
Performance
455BAL-1 1.2.1 Test for Correct
Adjustment
455BAL-2 1.2.1.1 Purge Test
455BAL-2 1.2.1.2 Lever Play
455BAL-3 1.2.2 Adjusting the 455
Balanced Regulator
455BAL-4 1.3 455 Balanced Regulator
Removal from Helmet
455BAL-6 1.4 455 Balanced Regulator
Disassembly
455BAL-6 1.4.1 Regulator Cover
Retainer Assembly
Disassembly
455BAL-7 1.4.2 Main Tube Disassembly
455BAL-9 1.4.3 Flex Knob Disassembly
455BAL-11 1.4.4 Main Tube Components
Disassembly
455BAL-13 1.4.5 Regulator Body and
Exhaust Disassembly
455BAL-14 1.5 455 Balanced Regulator
Reassembly
455BAL-14 1.5.1 Regulator Body and
Exhaust Reassembly
455BAL-16 1.5.2 Flex Knob Reassembly
455BAL-19 1.5.3 Main Tube Components
Reassembly
455BAL-22 1.5.4 Installing the Main
Tube into the Regulator Body
455BAL-25 1.5.5 Regulator Cover
Retainer Assembly
Reassembly
455BAL-27 1.6 Installing the 455 Balanced
Regulator onto the Helmet
1.1 General
VIDEO
Kirby Morgan 455
Balanced Regulator
https://www.youtube.com/
watch?v=niLRuNUNmTw
The 455 Balanced Regulator is an ultra-high per-
formance regulator, continuing the long line of
exceptional regulators from Kirby Morgan®. Its
construction and materials make it an extremely
rugged regulator.
NOTE
When storing the helmet for any length
of time, ensure that the flex knob, for
adjusting the regulator, is turned “out” fully
counterclockwise to avoid stressing the bias
spring. This will prolong the life of both the
inlet valve, seat, and bias spring.
1.2 455 Balanced Regulator
Performance
The 455 Balanced Regulator is an all stainless
steel regulator of a balanced design that offers
far greater overall breathing performance than
the non-balanced SuperFlow®and SuperFlow®
350 regulator.
1.2.1 Test for Correct Adjustment
Tools required:
• Regulated air supply, 135 to 150 psig
through Standard Scuba Second Stage Hose
To maintain optimum performance of the de-
mand regulator, it should be checked for proper
function and adjustment prior to commencement
of diving each diving day, in accordance with the
KMDSI Daily Set Up and Functional Checklist.
See the Kirby Morgan®or Dive Lab websites for

455BAL-2 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Performance 455 Balanced Regulator
the latest checklists at www.kirbymorgan.com or
www.divelab.com.
Check the regulator for adjustment and proper
function with the assembly complete, and at-
tached to a regulated gas supply (normally the
EGS system), adjusted to between 135–150 psig.
This can be done with the bent tube in place or
with the bent tube and bent tube adapter re-
moved and gas supplied through a standard
SCUBA hose.
Checking for proper adjustment of the 455
balanced regulator must be done with the
L.P. gas attached and turned on.
NOTE
135 to 150 psig over ambient is the standard
supply pressure to be used when adjusting
the 455 Balanced regulator.
1.2.1.1 Purge Test
1) Rotate the ex knob in, clockwise towards the
regulator body, until a clicking can be heard with
each full turn of the knob.
NOTE
This is an audible indication the tension of
the bias adjustment spring is as tight as it will
get. The adjustment knob will never bottom
out or stop turning in this direction and no
damage to the mechanism will occur. The
adjustment knob should only stop turning
when it is turned all the way out (counter
clockwise away from the regulator body).
2) Attach an L.P. regulated gas supply to regula-
tor inlet or helmet side block.
3) Turn on gas supply slowly.
4) Rotate the Flex Knob out counterclockwise
slowly, three full turns.
5) Lightly depress the regulator purge cover sev-
eral times and ensure the gas ow is stable.
NOTE
The regulator may free flow when purged
if there is no backpressure (resistance) in
the oral nasal, (e.g. the diver's face is not
correctly positioned into the oral nasal
mask). If the regulator free flows, simply
covering the air outlet tube of the regulator
inside the helmet or BandMask®should stop
any free flow.
6) Push in gently on the cover of the regulator.
There should be ⅛"–¼" free travel in the cover
before gas ow starts. When the cover is fully de-
pressed, a strong surge of gas must be heard.
7) If the purge cover has NO play, or play is
greater than ¼" BEFORE GAS ow is heard, the
demand regulator requires internal adjustment,
per "1.2.2 Adjusting the 455 Balanced Regulator"
on page 455BAL-3.
1.2.1.2 Lever Play
1) Turn the adjustment knob all the way in,
clockwise toward the regulator.
2) Remove the regulator cover retainer assembly
and diaphragm.
3) Attach an L.P. supply to the regulator inlet or
helmet side block.
4) Slowly turn on the gas supply.
⅛ " – ¼ "
Diagram of maximum lever arm travel.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-3
455 Balanced Regulator 455 Balanced Regulator Performance
5) Rotate the ex knob out (counterclockwise)
three full turns.
6) Check lever arm play, there should be between
⅛to ¼inch of free play in the lever and no gas
ow.
7) Depress the lever arm several times, ensure
a good ow and conrm the lever play does not
change.
If the lever play is outside the recommended pa-
rameters or if there is no strong gas ow when
the lever arm is depressed the regulator will re-
quire adjustment.
1.2.2 Adjusting the 455
Balanced Regulator
Tools required:
• Regulated air supply, 135 to 150 psig
through standard SCUBA Second Stage
Hose
• ¼inch Flat Head Screwdriver
•  inch Open End Wrench
• ⅞ (2) inch Open End Wrench
NOTE
The quickest and easiest way to supply
gas to the regulator for testing in between
adjustments is to use a standard first
stage scuba regulator with an open ended
standard second stage supply hose. The
female fitting will thread onto the inlet tube
in place of the bent tube adapter.
It is not necessary to remove the regulator from
the helmet to perform eld maintenance, howev-
er, for scheduled overhauls the regulator should
be completely removed from the helmet and dis-
assembled. The design of this regulator also al-
lows the technician to remove the main tube as
a complete unit for service or as a rapid replace-
ment in the eld.
NOTE
If there is too much play in the lever, the
adjustable nipple will need to be turned
out (counter clockwise). Too little play, the
nipple will need to be turned in (clockwise).
If the purge cover can be pushed in further
than ¹ ⁄₄ " the nipple will need to be turned out
slightly.
Exploded view of 455 Balanced regulator.
FLEX KNOB
WASHER
TRANSFER PIN
BALANCE SPACER
EXHAUST VALVE INSERT
JAM NUT
EXHAUST VALVE
RETAINER RING
INLET VALVE
LEVER
MAIN TUBE
LOCK CLIP
REGULATOR
COVER RETAINER
FRAME
REGULATOR
PURGE COVER
REGULATOR
COVER GUARD
DIAPHRAGM
ADJUSTMENT
SHAFT
ADJUSTMENT
NIPPLE
PACKING NUT
BEARING CLIP
SEAT
O-RING
O-RING
BENT TUBE
ADAPTER
O-RINGS
NOTE: two LP plugs for manufactur-
er’s test purposes only. Do not remove
unless O-rings require replacement.

455BAL-4 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Removal from Helmet 455 Balanced Regulator
Whatever direction is needed, make the adjust-
ment in very small increments and re-check af-
ter each adjustment. Usually  turn at a time or
less will sufce.
1) Remove the bent tube assembly, per "1.3.1 Re-
moval of the Bent Tube Assembly" on page BNT-4.
Remove the bent tube assembly.
2) Remove the bent tube adapter.
Remove the bent tube adapter.
3) Turn the adjustment knob all the way in
(clockwise toward the regulator) then back out
(counter clockwise) three full turns.
4) Insert a ¼ inch wide at head screwdriver into
the slot in the end of the adjustment nipple to
make adjustments as necessary. Be sure to at-
tach an L.P. gas supply and test the regulator
between adjustments.
Helpful
Hint
Turning the adjustment nipple in (clockwise)
will increase lever play and increase the
free range of the purge cover. Turning the
adjustment nipple out (counterclockwise)
decrease lever play and decreases the free
range of the purge cover.
Turn the adjustment nipple of a turn at a time
to adjust the performance of the regulator.
1.3 455 Balanced Regulator
Removal from Helmet
Tools required:
• Cutting Pliers
•  inch Open End Wrench
• (2) ⅞ inch Open End Wrench
• 1 ⅜inch socket or Regulator Mount Socket
Wrench P/N 525-625 (Found in 525-620 Tool
kit).
• ⅜inch Drive Extension with driver, mini-
mum 3 inches in length
• ¼inch Flat Blade Screwdriver
1) Remove the bent tube assembly, per "1.3.1 Re-
moval of the Bent Tube Assembly" on page BNT-4.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-5
455 Balanced Regulator 455 Balanced Regulator Removal from Helmet
Remove the bent tube assembly.
2) Remove nose block assembly, per "1.2.1 Nose
Block Assembly Removal" on page FCPRT-6.
3) Remove the screws, anodes or kidney plates
and whisker spacers from the whiskers.
Be sure to remove and set aside the whisker spacers.
4) Release the Oral Nasal Mask from its secure
t around the Regulator Mounting nut.
5) Clear the mask away from the Regulator
Mounting Nut and remove nut with sealing O-
ring.
6) Cut the tie wrap that connects the quad valve
exhaust main body to the water dump tube on
the helmet pod.
Cut the tie wrap that connects the quad valve exhaust
main body to the water dump tube on the helmet pod.
7) Remove the regulator assembly from the hel-
met.
Remove the regulator from the helmet.
8) The center section of the exhaust ange on

455BAL-6 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Disassembly 455 Balanced Regulator
the regulator body has a tie wrap holding it to
the helmet. Remove the tie wrap then stretch
the main exhaust body off the regulator exhaust
ange.
Remove the tie wrap.
Separate the regulator from the Quad
Valve™exhaust whiskers.
1.4 455 Balanced Regulator
Disassembly
1.4.1 Regulator Cover Retainer
Assembly Disassembly
Tools required:
• ¼inch Flat Blade Screwdriver
The 455 regulator cover retainer assembly in-
cludes the Cover Retainer Frame, Purge Cover,
Cover Guard and its associated mounting hard-
ware.
It is secured to the regulator body with four
stainless steel screws using a washer and lock
washer conguration. The two lower screws can
be changed to a bishop type pin which is stan-
dard when using the KM 97 water shroud.
The screws are captive and allow the technician
to partially unscrew the four screws to release
the cover assembly from the regulator body. The
screws will remain with the assembly. It is un-
necessary to completely unscrew the screws from
the retainer frame.
NOTE
If the purge cover is in good condition there
is no reason to remove it from the Regulator
Cover Retainer Frame.
1) Remove the four screws from the cover re-
tainer assembly completely only to inspect the
screws and verify all washers are present.
Loosen the screws and washers on
either side of the cover.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-7
455 Balanced Regulator 455 Balanced Regulator Disassembly
2) With the screws removed and the cover guard
separated pull the purge cover out of the cover
retainer.
3) Remove diaphragm and inspect. Check to de-
termine if diaphragm rubber has separated from
the metal disc. Hold the diaphragm to a bright
white light, while pulling and stretching to re-
veal damage, deterioration, or holes. Diaphragms
showing any indication of damage should be re-
placed. The diaphragm should always be replaced
during scheduled annual overhauls
Remove the diaphragm and inspect it carefully.
If it is torn or punctured it must be replaced.
1.4.2 Main Tube Disassembly
Tools required:
• ¼inch Flat Blade Screwdriver
• ⅞ inch Open End Wrench
•  inch Open End Wrench
1) Remove the bent tube assembly from the hel-
met, per "1.3.1 Removal of the Bent Tube Assem-
bly" on page BNT-4.
Remove the bent tube assembly.
2) Using a ⅞inch wrench, remove the bent tube
adapter and O-ring. Be careful not to lose the O-
ring.
Remove the bent tube adapter and O-ring.
3) Loosen the four screws on both sides of the
regulator cover.

455BAL-8 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Disassembly 455 Balanced Regulator
Loosen the screws and washers on
either side of the cover.
NOTE
These four screws should NOT be removed
from the cover assembly. The cover assembly
is designed to retain the screws to prevent
loss. Unthread the screws only enough to
allow the cover assembly to separate from
the main body of the regulator to expose the
interior parts.
4) Remove the cover assembly and diaphragm.
IMPORTANT
Inspect the diaphragm for holes or tears. If
it is torn or punctured it must be replaced.
Inspect the interior of the regulator for
foreign matter and clean if necessary.
Remove the cover assembly.
Remove the diaphragm and inspect it carefully.
If it is torn or punctured it must be replaced.
5) Insert the tip of a at blade screwdriver into
the slot at the top of the lock clip and slide the
clip away from the regulator main tube.
Carefully insert the tip of a at blade screwdriver
into the slot at the top of the lock clip to remove.
6) Using the " open end wrench, loosen the
packing nut about one turn. Next, while fully de-
pressing the lever arm, grasp the ex knob and
pull it straight away from the regulator body.
NOTE
It may be necessary to use a soft hammer to
break the main tube loose from the regulator
body.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-9
455 Balanced Regulator 455 Balanced Regulator Disassembly
This will remove the main tube as a single, easy
to handle unit.
When you pull the ex knob assembly out, the
main tube and related parts will follow.
1.4.3 Flex Knob Disassembly
Tools required:
• Small Screwdriver or Wooden Dowel (Chop-
stick)
• Table Vise
• O-ring Pick
1) Unscrew the ex knob assembly from the main
tube.
Unscrew the ex knob assembly from the main tube.
The transfer pin may fall from the end of
the shaft. Be careful not to lose it.
2) Remove the O-ring from the ex knob assem-
bly packing nut.
Inspect for signs of wear and replace if necessary.
Otherwise, if it is in good condition, set it aside
for cleaning and lubrication.
Remove the O-ring from the ex knob packing nut.
You can use a credit card, toothpick, or any clean soft
device that will not damage the O-ring or the nut.

455BAL-10 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Disassembly 455 Balanced Regulator
FLEX KNOB
WASHER
TRANSFER PIN
O-RING
ADJUSTMENT
SHAFT
“BOSS”
ADJUSTMENT
PACKING NUT
The adjustment shaft must be completely re-
moved to allow the removal of the ex knob. DO
NOT ATTEMPT to SEPARATE THE KNOB and
PACKING NUT without FIRST REMOVING the
ADJUSTMENT SHAFT.
3) Hold the packing nut while turning the ex
knob clockwise until it stops.
NOTE
You will notice the internal adjustment shaft
will travel outward AWAY from the packing
nut.
4) Insert a small screwdriver into the outer end
of the ex knob and push into the Flex Knob to
dislodge the adjustment shaft from the assembly
and remove.
The adjustment shaft must be completely removed to
allow the separation of the ex knob and packing nut.
5) Grab the packing nut with one hand or vise,
and the ex knob with the other and bend to sep-
arate the two parts.
With the shaft out, the ex knob can be
separated from the packing nut.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-11
455 Balanced Regulator 455 Balanced Regulator Disassembly
6) Using an O-ring pick, carefully remove the
shaft bearing washer and O-ring.
Using an O-ring pick, carefully remove the
bearing washer and adjustment shaft O-ring.
1.4.4 Main Tube Components
Disassembly
Tools required:
• Flat Blade Screwdriver
• Wooden Dowel (Chopstick)
1) Remove the O-ring from the exterior of the
main tube.
NOTE
Check the condition of this O-ring very
carefully. If there are any signs of damage, it
must be replaced. Pay close attention to this
seal!
Remove the O-ring from the main tube.
2) Remove the bearing clip.
Remove the bearing clip.
3) Remove the lever by slightly pulling one leg
out from the slot on the main tube, followed by
the second leg.
4) Slide the balance spacer, spring, and inlet
valve assembly out from the main tube and sepa-
rate.

455BAL-12 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Disassembly 455 Balanced Regulator
Remove the balance spacer, spring and inlet
valve assembly from the main tube.
5) Using a at blade screwdriver, unscrew the
adjustment nipple all the way out to free the
threads from the main tube.
Unscrew the adjustment nipple all the way
out to free the threads from the main tube.
6) Use the wooden dowel rod (chopstick) to push
it free.
NOTE
Carefully check the inlet nipple O-ring for
damage, even small cuts may cause leaking.
Inspect all parts for signs of wear or damage
and replace if necessary.
BALANCED SPACER
INLET VALVE
LEVER ARM
MAIN TUBE
ADJUSTMENT
NIPPLE
BEARING CLIP
SPRING
SEAT
O-RINGS
O-RINGS
Details of the 455 Balanced main tube and associated parts.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-13
455 Balanced Regulator 455 Balanced Regulator Disassembly
Use the wooden dowel rod to push it free.
1.4.5 Regulator Body and
Exhaust Disassembly
Tools required:
• Small Flat Blade Screwdriver
•  inch Allen Wrench
1) Remove the exhaust valve insert retainer ring
from the regulator body.
Use a small at blade screwdriver to
remove the exhaust valve insert retainer
ring from the regulator body.
2) Remove the exhaust valve assembly and its
sealing O-ring from the regulator body and sepa-
rate the exhaust valve from the insert.
Remove the exhaust valve insert assembly.
3) Inspect all parts for signs of wear or damage
and replace if necessary.
4) Inspect the interior of the regulator for foreign
matter and clean if necessary.
If performing an annual overhaul
5) Remove the two port plugs and their O-rings
and replace the O-rings.

455BAL-14 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Reassembly 455 Balanced Regulator
Remove the two port plugs and
their O-rings and replace.
1.5 455 Balanced
Regulator Reassembly
When reassembling the 455 Balanced regulator
use only an oxygen compatible lubricant. We cur-
rently use the reference to lubricate using Chris-
to-Lube®or equivalent oxygen compatible lu-
bricant and would like to acknowledge Krytox®,
Fluorolube®and Tribolube®as equivalent oxygen
compatible lubricants.
1.5.1 Regulator Body and
Exhaust Reassembly
Tools required:
• Flat Blade Screwdriver
1) Inspect the interior of the regulator body and
make sure that it is clean and there is no foreign
matter.
S.S.
REGULATOR BODY
EXHAUST VALVE INSERT
RETAINER RING
O-RING
EXHAUST
VALVE
455 Balanced exhaust valve mechanism.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-15
455 Balanced Regulator 455 Balanced Regulator Reassembly
The regulator body must be clean
and free of foreign matter.
2) Install the O-ring for the exhaust valve insert,
into the regulator body.
3) Install the new exhaust valve into the exhaust
valve insert.
NOTE
Use care to ensure the valve is mated to the
proper side of the exhaust valve insert. The
exhaust valve installs on the side that has the
ring support.
BWARNING
If the exhaust valves are installed
backwards, they will leak. This may
result in serious injury or death.
Install the new exhaust valve (if needed) into
the insert. Use care to ensure the valve is mated
to the proper side of the exhaust insert.
4) Place the exhaust valve insert with exhaust
valve installed on top of the O-ring.
NOTE
The exhaust valve insert must be oriented
so that it seals against the O-ring and the
exhaust valve will mate properly with the
insert.
Install the O-ring and valve insert.
5) Install the retainer clip.
NOTE
A flat blade screwdriver can be used to
push the retainer clip into the groove. The
clip should lock into place. Make sure it is
pressed into the groove completely. This is
extremely important to prevent the exhaust
components from becoming dislodged. The
ends of the ring should have a gap between
them.
GAP
FREE END
Install the retainer clip.
6) Cut off any excess tail from the exhaust valve
that protrudes into the regulator body.
7) To test to see if the insert is installed properly
by trying to spin the insert. It should be difcult,
or not able to turn. You should not be able to dis-

455BAL-16 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Reassembly 455 Balanced Regulator
lodge the insert by hand. Also check to make cer-
tain the exhaust valve will not get caught on the
free end of the retainer clip which will cause the
valve to ap open.
To test to see if the insert is installed
properly, try to spin the insert. It should
be difcult, or not able to turn.
If performing an annual overhaul
8) Install O-rings onto port plugs and install into
regulator body.
Install O-rings onto port plugs and
install into regulator body.
1.5.2 Flex Knob Reassembly
Tools required:
• Christo-Lube®or Equivalent
• Table Vise
• A Rag or Cloth
1) Lubricate the O-ring and shaft bearing washer
then place the O-ring into the adjustment pack-
ing nut followed by the shaft bearing washer.
Press the washer down with a nger to lock the
components into the adjustment packing nut.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-17
455 Balanced Regulator 455 Balanced Regulator Reassembly
Place the O-ring into the adjustment packing
nut followed by the shaft bearing washer.
2) Lightly lubricate the groove in the end of the
ex knob where it presses into the packing nut
with Christo-Lube®or equivalent oxygen compat-
ible lubricant.
Lightly lubricate the groove in the end of the ex knob.
3) Place the packing nut into a vise and insert
the ex knob into the adjustment packing nut at
an angle, twisting the knob while pushing down
into the adjustment packing nut.
NOTE
Use of a rounded tool or the shaft of a
screwdriver to push the flex knob into the
adjustment packing nut can be useful.
Place the packing nut into a vise and insert the ex
knob into the adjustment packing nut at an angle.
4) Lubricate the threads of the adjustment shaft
with Christo-Lube®or equivalent and insert into
the ex knob.

455BAL-18 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Reassembly 455 Balanced Regulator
Lubricate the threads of the adjustment
shaft with Christo-Lube®or equivalent
and insert into the ex knob.
5) Push on the adjustment shaft’s end while
turning the ex knob counterclockwise to engage
threads. Continue turning the ex knob counter-
clockwise until the ex knob stops.
Push in on the adjustment shaft while turning the
ex knob counterclockwise to engage threads
6) Lubricate and install the external O-ring onto
the adjustment packing nut.
BALANCED SPACER
INLET VALVE
LEVER ARM
MAIN TUBE
ADJUSTMENT
NIPPLE
BEARING CLIP
SPRING
SEAT
O-RINGS
O-RINGS
Details of the 455 Balanced main tube and associated parts.

© MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002 455BAL-19
455 Balanced Regulator 455 Balanced Regulator Reassembly
1.5.3 Main Tube Components
Reassembly
Tools required:
• Christo-Lube®or Equivalent
• Small Flat Blade Screwdriver
Replace any parts if damage is present or sus-
pected. If a normal overhaul is being conducted
replace all soft goods. Lubricate O-rings and mov-
ing parts with a light coating of Christo-Lube®,
Krytox®, Fluorolube®, or Tribolube®are also ac-
ceptable lubricants.
1) Install the O-ring onto the main tube.
Install the O-ring onto the main tube.
2) Install the two O-rings onto the balance spacer
and lubricate with Christo-Lube®or equivalent
and set aside.
BWARNING
DO NOT OVER LUBRICATE THE O-
RINGS ON THE BALANCE SPACER.
Excess lubrication could possibly col-
lect at the end of this part and block
the critical air balancing hole.
Do not over lubricate the O-rings
on the balance spacer.
3) Spread the arms of the lever just enough to in-
stall it onto the main tube. The cross member on
the lever should rest on the at spot of the main
tube where you can read the part number 550-
161.
NOTE
Study the features of the inlet valve
assembly. There are four “wings” towards
one end of the assembly and a bore that
creates the balance chamber on the opposite
end.
The wings that align with the lever arm are the
two that have an additional wall for the lever
arm to bear on. The valve assembly should be
inserted into the main tube with these walls to-
ward the bottom of the regulator tube.

455BAL-20 © MMXXI Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 210914002
455 Balanced Regulator Reassembly 455 Balanced Regulator
Close-up detail of the inlet valve.
4) With the spring in place, using the balance
spacer with the two O-rings installed, insert the
balance spacer into the stainless steel tube of the
inlet valve, stop at the second O-ring.
Using the balance spacer with the two
O-rings installed, insert the rst O-ring into
the open end of the inlet valve and stop.
5) Properly align the wings found on the inlet
body and insert the inlet valve into the main
tube, as previously noted.
NOTE
If this is done properly, the lever should lift
up when pressure is applied. If it does not,
the valve has not been inserted correctly.
Align and insert the inlet valve into the main tube.
6) While holding the inlet valve in position, pinch
each arm of the lever and slowly remove the bal-
ance spacer.
The inlet valve should remain in place while
pinching the lever arms. If it comes out, repeat
the process until the valve stays in place.
7) Install the spring and balance spacer as a unit
into the main tube.
NOTE
Confirm the balance spacer is properly
aligned inside the main tube by pushing in
on the end of the spacer, to see that the lever
arm moves when pressure is applied.
Install the spring and balance spacer
with O-ring into the main tube.
8) Lightly lubricate the ends of the transfer pin
and install into the end of the balanced spacer.