OMS Workhorse Series User manual

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Service Guide for the OMS
Workhorse Regulator
OMSLLCP.O. Box 146, Montgomery, NY 12549
Toll Free Dealer only numbers (domestic)
Phone: [phone] fax: [phone]
Phone: [phone] fax: [phone]
www.omsdive.com
E-mail: [email protected]

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Service Guide for the OMS Workhorse Regulator
Introduction
This manual is to be used only by technicians authorized by Ocean Management
Systems (OMS LLC). It is a guide to assist in the servicing of the OMS Workhorse Regulator
and should be used only after the technician has received sanctioned training on servicing this
specific regulator. It is necessary for the technician to have an understanding of basic
regulator principles, compressed air safety, and the proper use of the tools required. This
manual is not intended to be a complete regulator repair course.
NOTE: Many repair parts may be similar in appearance but have different physical or
chemical properties. Use only parts from OMS repair kits for OMS regulators.
Substituting parts can compromise the function of OMS regulators.
General Guidelines
xOMS regulators should be serviced annually regardless of usage. There are seals
under constant spring tension that must be replaced every year to insure peak
performance. Regulators under heavy use conditions may require more frequent
service.
xThe customer should also understand the importance of a pre-dive inspection of
external regulator parts like hoses and mouthpieces.
xThe customer should be advised of the importance of post dive maintenance as
outlined in the user manual.
xMoisture should never be allowed to enter the inlet of the first stage.
xNever depress the purge button of the second stage while submerged if there is no
pressure from the first stage. This could allow water to enter the demand valve.
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adjustments inside the regulator. Adjustments or repairs are to be performed only
by authorized technicians.
xNever use aerosol products such as lubricants or cleansers on OMS regulators.
Aerosol propellants can attack rubber and plastic parts.
xA technician encountering any unusual situations or conditions not outlined in this
manual should contact OMS technical support immediately

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Pre-service Inspection
The Workhorse Regulator from OMS consists of an unbalanced piston first stage and a
downstream demand valve second stage. The first step in servicing the regulator is to
assess its condition prior to servicing. Note the condition of the second stage housing,
looking for any obvious cracks or other damage. Inspect the body of the first stage for
corrosion or damage. Compromises in the chrome finish can allow corrosion to form
causing pitting in the metal underneath. Any parts found to be worn and damaged should
be replaced during the servicing. All the parts found in the service kit should be replaced
annually regardless of condition.
Connect a quick disconnect BC hose to a low pressure port on the first stage then attach
an intermediate pressure gauge (0-300 p.s.i.). When the regulator is pressurized to 200
bar (3000p.s.i.) the pressure at the low pressure port should read 135 p.s.i. Make a note
of the intermediate pressure before servicing.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
First Stage Disassembly
Use an open end wrench to disconnect the second stage hose from the first stage. Use an
open end wrench to remove the high pressure console hose if present. Use an allen
wrench to remove any remaining port plugs.
Secure the first stage (end cap up) in a padded vise being careful not to scratch or damage
the chrome finish. You can also thread an expended CO2 cartridge into a low pressure
port to provide a work handle.
Use a heavy strap wrench (or an appropriately sized pipe spanner) to remove the first
stage end cap. There is spring tension under the cap so be careful as the end cap
unthreads. Remove the end cap and grasp the exposed stem of the piston exposed inside.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Remove the main spring, piston, and shims from the endcap. Inspect the first stage body,
spring, and piston for cracks, corrosion or other damage. Replace if needed. Pay
particular attention to threaded areas.
Use an allen wrench to remove the filter retainer from the DIN connector assembly.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Once the filter retainer has been removed from the tip of the DIN connector assembly, the
DIN handwheel should slide off the DIN connector body.
With the filter retainer removed, the conical filter should drop out of the DIN connector.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Remove the body of the DIN connector assembly using an open end wrench.
Remove O-rings from piston head and piston stem. Be careful not to scratch metal
surfaces. Use a narrow metal probe to push up through the piston head and dislodge the
high pressure seat at the end.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
The high pressure seat should come out of the piston by gently pushing on the probe. If
the seat does not move make sure the diameter of the probe is smaller than the passage
through the shaft of the piston.
Cleaning and Lubrication
Clean parts in CORROSTOP cleaning solution or ultrasonic cleaner. Do not expose parts
to ultrasonic agitation for more than five minutes otherwise chrome plated surfaces could
be damaged. A soft nylon brush can be used to loosen deposits. Thoroughly rinse all
parts in clean fresh water then use clean dry compressed air to gently blow parts dry.
Examine all metal surfaces for corrosion, cracking or scratches paying particular attention
to threaded areas and the internal orifice that contacts the high pressure seat.
OMS ® Oxygen Compatible Grease is the recommended lubricant for OMS regulators.
Use minimal amounts of lubricant where called for. Excess lubricant can trap
particulates and act as a contaminant.
If the regulator is to be used for oxygen service, clean all parts using the appropriate O2
cleaning procedures.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
First Stage Reassembly
Install new O-ring on piston head. Place new high pressure seat on a clean flat surface.
Push the piston stem straight down on the new seat and press into place.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Lightly lubricate the piston head O-ring with a very small amount of oxygen compatible
grease. The O-ring should look shiny but no lubricate should be seen. If you can see
OXEULFDQWLW¶VWRRPXch. Re-install piston (head first) into end cap being careful not to
dislodge the O-ring from its groove.
Replace plastic shim onto piston stem followed by the main spring. Place the next plastic
shim on the exposed end of the main spring.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Mate the first stage body with the threads of the end cap. It will be necessary to apply
downward pressure while rotating the body before the threads will engage. Maintain the
alignment of the main spring and shim while rotating the body.
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WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Replace O-ring on the DIN connector body. Apply a small drop of mild threadlocker
solution to the internal threads of the first stage body then mate the body of the DIN
connector with the first stage body.
Install O-ring on the new conical filter and insert conical filter (narrow end first) into
DIN connector body.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
Slide DIN handwheel onto DIN connector body oriented with the handwheel against the
1st stage body. Replace the O-rings on the filter retainer then thread filter retainer into
DIN connector body.
Use an allen wrench to tighten the filter retainer to the DIN connector body.

WARNING! OMS£SERVICE MANUALS ARE TO BE UTILIZED BY OMS TRAINED AND
AUTHORIZED TECHNICIANS ONLY. Improper service and or repair attempts by an untrained or uncertified
person(s) is not authorized by OMS, and could result in equipment failure causing serious injury or death .
First Stage Testing
I. Connect a tested second stage or an over-pressure relief valve to one of the low
pressure ports of the first stage prior to testing. This will allow excess air pressure
to vent in the event of a problem with the first stage.
II. Connect an intermediate pressure gauge (0-300 PSI) to one of the first stage low
pressure ports and plug the rest of the ports.
III. Slowly turn on the air to the first stage. If the reading on the intermediate gauge
starts to rise above 150 PSI turn off the air immediately.
IV. The pressure should rise to 135 PSI (+\- 9 PSI) and remain steady. This is the
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V. Once the intermediate pressure has stabilized check the first stage for air leaks.
Pay particular attention to the ambient openings on the first stage body.
VI. Purge the second stage and watch the reading on the intermediate pressure gauge.
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When the purge button is released and the air flow stops the intermediate pressure
gauge should return precisely to the original lock up pressure.
VII. Cycle the regulator by pressing the purge button several times. The intermediate
pressure gauge needle should respond mechanically and precisely returning to its
lock up pressure each time without any rise or drop.
Basic First Stage Troubleshooting
Symptom Possible Causes Correction
High pressure air
seeping past seat and
orifice
Check condition of high
pressure seat and replace if
needed.
Check orifice for corrosion or
flaws and replace first stage
body if needed.
Intermediate pressure above 145 PSI
Increased spring
tension from main
spring
Check shims under main
spring, remove one shim if
needed.
Check for deposits or corrosion
under piston head. Re-clean
piston.
Low inlet pressure Be sure regulator is connected
to 3000 PSI air source.
Intermediate pressure below 125 PSI
Decreased spring
tension from main
spring
Add one extra shim under
spring. Replace spring if
needed.
Buzzing or honking upon inhalation Air flow causing
harmonic vibration of
internal components
Check piston for excess
lubricant. Reverse main spring
or replace spring if problem
persists.