Momentum MN 39 Series User manual

Published June 1, 2017
U-0181-MFT Series MN 39
OPERATORS MANUAL – MN 39 SERIES

Momentum Fuel System
MN 39 Series
Fuel Management Module
Revision 2A 01 Jan 2017

MN 39 Series Stand Alone FMM i
I. Legal Disclaimer
All information and illustrations in this manual are
the property of Momentum Fuel Technologies. Any
photographs or graphics presented in this manual are for
representational purposes only. All content is based on
the latest information available at the time of publishing.
As part of our continuous product improvement policy,
we may modify information, illustrations, and/or
specications to explain and/or exemplify a product,
service, or maintenance improvement. We reserve the
right to make any change at any time without notice.
No part of this publication may be reproduced or used in
any form without the without the written permission of
Momentum Fuel Technologies.
II. Preface
This manual is for Stand Alone Fuel Management
Modules (FMM) MN 39 Series. Service information is
available by calling Momentum at 1-844-CNG-TANK.
DO NOT attempt to fill, defuel, vent, or perform basic
maintenance on the system until you have read and fully
understand the information presented in this manual.
If you have questions about any part of this manual,
contact Momentum at 1-844-CNG-TANK.
This manual must always be kept in the vehicle so it
is accessible to the operator at all times. This manual
includes information that is important for the safety of the
operator and First Responders (i.e. police, re ghters) in
the event of an emergency.
The following abbreviations are used throughout this
manual:
1. CNG, which means Compressed Natural Gas.
2. FMM, which means Fuel Management Module
III. Warning Statements
Warning statement denitions used in this
manual.
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury. The word
“DANGER” applies to the most extreme situations.

ii MN 39 Series Stand Alone FMM
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
Indicates a hazardous situation or unsafe practice
which, if not avoided, could result in minor or
moderate injury.
NOTICE
Indicates practices not related to personal injury. The
safety alert symbol shall not be used with this signal
word.

MN 39 Series Stand Alone FMM iii
Table of Contents
In Case of Emergency .................................................... 1
Fuel System Shut Down Procedure................................... 1
Location of Manual Shut-Off Valves ................................ 1
If You Suspect a Fuel Leak ................................................4
If the Vehicle is Involved in an Accident...........................4
If the Vehicle is on Fire...................................................... 5
First Responder Alerts and Procedures ...........................6
Fire Response Guidelines ..................................................6
Safety..................................................................................9
Safety Tips........................................................................ 10
CNG Vehicle Safety Precautions.......................................11
Codes and Compliances................................................... 12
Introduction .................................................................. 13
System Overview.............................................................. 13
Compressed Natural Gas................................................. 13
Fuel Standards................................................................. 14
Specications ................................................................... 14
Components..................................................................... 14
Inspection and Operation .......................................... 19
Pre-Trip Inspection ......................................................... 19
Weekly System Inspection............................................... 19
Starting the Vehicle .........................................................20
Fueling ............................................................................20
Fueling the CNG System.................................................. 21
Fast and Slow Fill and Pressure/
Temperature Guidelines..................................................24
Defueling and Fuel Transfer Guidelines .........................25
Fuel System Defueling Procedure ................................... 27
Scheduled Maintenance..............................................28
Maintenance Schedule.....................................................28
Maintenance Part Numbers ............................................29
Depressurizing Procedure ...............................................30
Re-pressurizing Procedure..............................................30
High Pressure Filter Drain Procedure ............................ 31
High Pressure Filter Change Procedure.......................... 31
Cylinder and Fuel System Inspections............................32
Periodic In-Service Inspection Requirements ...............32
Welding and Hot Work Procedures ...............................33

iv MN 39 Series Stand Alone FMM
CNG Decals ........................................................ 34
CNG Labels ......................................................................34
Towing and Lifting........................................................35
Lifting the Vehicle............................................................35
Towing the Vehicle ..........................................................35
Service and Support.....................................................36
Momentum Parts and Service Hotline ...........................36
Dealer Locator ................................................................36
Warranty.........................................................................37
Warranty Procedures....................................................... 37
Warranty Statement ....................................................... 37

MN 39 Series Stand Alone FMM 1
Section 1 — In Case of Emergency
In Case of Emergency
Natural Gas Vehicles (NGVs) are subject to the
requirements of the National Fire Protection Association
(NFPA). NFPA 52, the Vehicular Gaseous Fuel Systems
Code, details the safety requirements for NGVs and their
fueling facilities.
Fuel System Shut Down Procedure
In the event of an emergency or the vehicle requires
service, shut down the CNG fuel system using the
procedure below.
Location of Manual Shut-Off Valves
(Figure 1)
•Red Handle on the Fuel Management Module
(FMM)
FMM
MANUAL
SHUT-OFF
VALVE
FIGURE 1 – MANUAL SHUT-OFF VALVES

2 MN 39 Series Stand Alone FMM
Section 1 — In Case of Emergency
Step 1 – Turn OFF the Fuel Management Module
(FMM) Manual Shut-Off Valve
The FMM Manual Shut-Off Valve isolates the fuel storage
system from the engine. The FMM Manual Shut-Off Valve
is RED and clearly labeled for easy identication.
(Figure 2)
To turn OFF the FMM Manual Shut-Off Valve:
1.
2.
Turn the ignition OFF and set the parking brake. Do
not set the parking brake if the vehicle is being towed.
Open the fuel access door and locate the red Manual
Shut-Off Valve.
3. Turn the valve clockwise 1/4 turn to the OFF position.
Step 2 – Turn OFF the Fuel Cylinder Manual Shut-
Off Valve(s)
The Fuel Cylinder Manual Shut-Off Valve on each tank
isolates the fuel inside that tank.
NOTE: The Fuel Cylinder Manual Shut-Off Valve is
designed so that it does not turn off pressure in the
Pressure Relief Devices (PRDs) lines. This is a safety
design so the CNG fuel system PRDs can still activate
when the valves are shut off.
1/4 TURN
FIGURE 2 – FMM MANUAL SHUT-OFF VALVE

MN 39 Series Stand Alone FMM 3
Section 1 — In Case of Emergency
To turn OFF the Fuel Cylinder Manual Shut-Off Valve:
1. Open the valve access cover to the fuel cylinder by turning the butterfly
bolts counterclockwise. Locate the Fuel Cylinder Manual Shut-Off Valve.
(Figure 3)
Turn the valve clockwise until handle stops. (Figure 4)
NOTE: Use this method to turn OFF the valve on EACH tank. (Figure 5)
FIGURE 4– CYLINDER MANUAL SHUT-OFF VALVE
2.
TURN
FIGURE 3 – CYLINDER MANUAL SHUT-OFF VALVE ACCESS COVER
FIGURE 5– CYLINDER MANUAL SHUT-OFF VALVE

4 MN 39 Series Stand Alone FMM
Section 1 — In Case of Emergency
If You Suspect a Fuel Leak
Compressed natural gas is flammable and explosive.
Serious personal injury can occur if leaking gas is
ignited. If you suspect a leak, do not operate the
vehicle. The vehicle must be inspected by a qualified
technician before being returned to operation.
If You Smell a “Rotten Egg” Odor
An odorant which smells like rotten eggs is added to
compressed natural gas to aid in detection of a leak. If
you notice this kind of lingering odor coming from your
vehicle, you may have a leak in the CNG fuel system.
NOTE: It is normal to detect this slight odor when the
fueling nozzle is being connected or disconnected during
the refueling process. The odor should quickly dissipate
when fueling has been completed.
Other Signs of a Fuel Leak
If you notice any of the following, you may have a leak in
the CNG fuel system:
• Frosting at suspected leak point
• Bubbling in wet area
• Blowing or hissing sound
• Flames, if a leak has ignited
If the Vehicle is Involved in an Accident
If the vehicle is involved in any accident or is leaking fuel,
perform the following procedure.
If the vehicle is involved in any accident occurring in
excess of 5 mph, the fuel system MUST be inspected
by a CSA-qualified fuel system inspector before being
returned to service.
1. Turn the ignition switch OFF, turn the main battery
OFF, and set the parking brake.

MN 39 Series Stand Alone FMM 5
Section 1 — In Case of Emergency
2. Eliminate all ignition sources such as re, sparks,
electronics, lights, or electrostatic charges. Never
smoke near the disabled vehicle and do not light road
ares or let First Responders near the vehicle.
3. If it is safe to do so, open the FMM access door and
turn the FMM Manual Shut-Off Valve 1/4-turn
clockwise to OFF position.
4. Open the service access panel. Turn all Fuel Cylinder
Manual Shut-Off Valves clockwise 1/4-turn to the OFF
position.
5. Conduct a visual check of the damaged area of the fuel
system for signs of leaks.
6. Keep pedestrians and trafc away from the area.
7. If towing service is called, inform the operator of
the presence of CNG and give guidance on proper
safety procedures. Refer to the CNG Vehicle Safety
Precautions procedure.
8. Have a qualied Momentum Service Technician
inspect the fuel system and make any necessary
repairs. Qualied service support can be found at
www.momentumfueltech.com
If the Vehicle is on Fire
1. Turn the ignition switch OFF.
2. Exit the vehicle in the safest manner possible.
3. Call 911.
4. If safe to do so, extinguish the re using an
appropriately-rated re extinguisher.
5. Establish a safety zone of not less than 100 feet.
6. Report the following to the First Responder (i.e. police,
re ghters) when they arrive on site.
a. Vehicle is a CNG vehicle
b. Amount of fuel in the tank (psi reading if known)
c. Number of tanks
d. Location of the vent system
7. Have the vehicle inspected by a qualied technician
to ensure integrity of the CNG fuel system. Qualied
service support can be found at www.momentum
fueltech.com

6 MN 39 Series Stand Alone FMM
Section 1 — In Case of Emergency
First Responder Alerts and Procedures
These procedures are intended for EMERGENCY
PERSONNEL ONLY (i.e. police, re ghters). Emergency
First Responders are specially trained to handle
emergencies involving alternative fuel vehicles. These
instructions are not intended for untrained, unqualied
individuals. DO NOT attempt to perform these procedures
on your own. Call 911 and follow any preliminary
emergency steps listed at the beginning of this section.
First Responder Emergency Procedure
1. Shut down the fuel system per the Fuel System Shut
Down Procedure at the beginning of this section.
2. Turn the battery disconnect switch to OFF.
3. Notify additional emergency personnel, if needed.
Fire Response Guidelines
Observe the following warnings when responding to
a fire involving a CNG vehicle. Failure to do so can
result in serious personal injury or death.
If the fuel cylinders or fuel cylinder housing ARE NOT
involved in the fire, use normal response tactics to
extinguish the fire.
If fire is impinging on the cylinder housing or the
cylinders are on fire, move to a safe distance and let
the vehicle burn to protect the public and yourself
from the possibility of an explosion hazard.
DO NOT apply water to the cylinder housing or
cylinder. Applying water can prevent the PRDs from
activating, resulting in a catastrophic cylinder failure
causing an explosion.

MN 39 Series Stand Alone FMM 7
Section 1 — In Case of Emergency
Pressure Relief Devices (PRDs) on the CNG fuel system
will activate at 230°F, releasing pressurized gas
through the vent ports. (Figure 6 and 7) This is to
evacuate as much fuel as possible from the fuel
cylinders.
If fire exists and the PRDs do not activate, the cylinder
pressure can increase to above the rated pressure
(5,000 psi) causing a probable hazardous situation.
Clear the area as far as possible and let the vehicle
burn.
When Pressure Relief Devices (PRDs) activate, the
result could jet fire. Pressure within the system will
determine the duration and distance of the jet fire. The
fuel can re-ignite several times. Clear the area as far
as possible and let the gas burn off.
NOTICE
The amount of fuel will determine how long it takes for
the fuel to be vented. On average, it takes 20 minutes
to vent out all the gas through the vent system from
PRD activation.
FIGURE 7– PRESSUR RELIEF DEVICE
FIGURE 6– VENT PORTS

8 MN 39 Series Stand Alone FMM
Section 1 — In Case of Emergency
NOTICE
Once PRDs have activated and gas has stopped
venting, it is safe to put water on the system.
NOTICE
After the fire is out, allow time for the system to cool
before approaching the vehicle.

MN 39 Series Stand Alone FMM 9
Section 2 — Safety
Safety
The CNG fuel system has several significant
differences from the typical diesel fuel systems used
in heavy trucks. The fuel lines are under high pressure
and leaking fuel can easily ignite. It is important to
observe all safety statements in this manual to ensure
safe operation of a CNG vehicle. Never disregard a
safety directive.
It is the responsibility of the operator to read and
understand all Warnings, Cautions, and guidelines
in this manual BEFORE operating the vehicle or
performing maintenance. Contact Momentum Fuel
Technologies if you do not clearly understand any
part of the material presented here. Do not attempt
to conduct any procedure you do not completely
understand. Do not perform any procedure for which
you do not have the specified Momentum Fuel
Technologies parts or required tools. Failure to do so
can result in serious personal injury, or death.
Compressed natural gas is flammable and highly
explosive. Serious personal injury can result if leaking
natural gas ignites. If a leak is suspected, have the
vehicle immediately inspected and repaired before
returning it to operation.

10 MN 39 Series Stand Alone FMM
Section 2 — Safety
One should never detect (smell) gas or hear gas
escaping at any other time besides refueling. If the
smell of natural gas or a hissing sound is detected at
any time besides refueling, the CNG system should
be shut down. Refer to the Fuel System Shut Down
Procedure.
Only trained and qualified personnel should service
this natural gas vehicle. Components in the fuel
system are under extreme pressure. Severe injury or
death can result from improper service or failure to
follow safety precautions.
Safety Tips
1. A portable re extinguisher having a UL rating not
less than 20 B:C should be accessible and visible. Fire
extinguishers must always be kept fully charged and up
to date.
2. Always wear protective footwear and eyewear when
conducting fueling operations.
3. Inspect for leaks using a methane detector or Swagelok
Snoop® only. Do not use any other method or products
to nd leaks.
4. Do not attempt to tighten or loosen ttings when the
fuel system is under pressure.
5. Always use tools that are in proper working order and
properly calibrated.
6. Appropriate work attire must always be worn when
servicing or maintaining fuel system. Never wear loose
clothes, rings or loose neck chains.
7. All maintenance and service procedures must be
conducted in an environment that is free of dust.
8. Perform service only in CNG-approved facilities.
9. For any maintenance that may create a spark or ame,
follow the Welding and Hot Work Procedures.

MN 39 Series Stand Alone FMM 11
Section 2 — Safety
10. In accordance with federal law, any CNG fuel system
vehicle must always be labelled to signify it as a CNG
vehicle. The vehicle must be marked with a weather-
resistant diamond-shaped label located on an exterior
vertical or near-vertical surface on the lower right rear
of the vehicle (on the trunk lid of a vehicle so equipped,
but not on the bumper of any vehicle), inboard from
any other markings. The label shall be approximately
4-3/4 inches by 3-1/4 inches. The marking shall consist
of a border and the letters “CNG” (one inch minimum
height centered in the diamond) of silver or white
reective luminous material on a blue background.
CNG Vehicle Safety Precautions
Following proper safety and handling practices is
necessary when operating a compressed natural
gas fuel system. Adhere to the following safety
precautions when operating compressed natural gas
fuel systems. Failure to do so can result in serious
personal injury or death.
1. Always have at least one re extinguisher with a UL
rating of 20 B:C or more installed on the vehicle in a
place that is easily accessible. The extinguisher must be
labeled or marked with that rating. Fire extinguishers
must always be kept fully charged and in good
mechanical condition. Fire extinguisher mounting
brackets must allow visual determination of being fully
charged.
2. If a gas leak is detected, do NOT try to start vehicle.
Refer to the If You Suspect a Fuel Leak procedure.
3. Never perform service on the system when it is
pressurized.
4. Do not allow the system pressure to exceed working
pressure.
5. Do not smoke or produce open ame within 50 feet a
CNG dispensing/lling station.
If the vehicle requires service work that would
generate flames, sparks, or excess heat, purge the
CNG system completely with an inert gas. Failure to
do so can result in a fire or explosion.

12 MN 39 Series Stand Alone FMM
Section 2 — Safety
Codes and Compliances
For more information on CNG fuel system requirement in
general, refer to following CNG codes and regulations:
•CGA C-6.4 CNG System Inspection Standard (also
covers installation)
•FMVSS 304 (DOT) Cylinder Standards
•NFPA 52 Vehicular Gaseous Fuel Systems Code. 2016
Edition
•ANSI/NGV 2 CNG Vehicle Container requirements
•ANSI/IAS PRD 1 Pressure Relief Devices
•ANSI/IAS NGV 3.1 Valves, Fittings and Brackets
•Canada: CAN/CGA B109, CSA Group
•North America: ANSI/AGA NGV 3.1/CGA 12.3 and
NGV 12.3-M95
•Compressed Natural Gas and Liquefied Natural Gas,
Railroad Commission of Texas January, 2013

MN 39 Series Stand Alone FMM 13
Section 3 — Introduction
Introduction
System Overview
The engine in this vehicle is fueled by a compressed
natural gas (CNG) system designed by Momentum Fuel
Technologies. The system uses the same type of gas used
in household appliances such as ovens and dryers.
The main difference is that natural gas vehicle fuel is
stored under high pressure (3,600 psi [24,800 kPa]).
Compressed Natural Gas
CNG is a naturally occurring hydrocarbon gas mixture
which consists primarily of methane.
It is:
• Colorless
• Odorless
• Non-corrosive
• Non-toxic
This gas is lighter than air, which means if gas were to
leak, it would oat upwards and quickly dissipate into
the atmosphere. CNG will burn only when in an air-
to-gas mixture of approximately 5-15% so its range of
ammability is limited compared to other fuels. The
gas also has an ignition temperature of 1076°F which
is signicantly higher than diesel. As a fuel, CNG is less
expensive and burns cleaner than diesel fuel, producing
low emissions. These characteristics make CNG an
efcient, safe choice for fueling vehicles.
Compressed natural gas is flammable and highly
explosive. Serious personal injury or death can result
if leaking natural gas ignites. If a leak is suspected,
have the vehicle immediately inspected and repaired
before returning it to operation.
CNG is odorless and invisible in its natural state. To
aid detection, a chemical odorant called mercaptan
is added to it which gives it a distinctive, pungent
smell, similar to “rotten eggs”. If you notice this kind
of lingering odor coming from your vehicle, you may
have a leak in the CNG fuel system.

14 MN 39 Series Stand Alone FMM
Section 3 — Introduction
One should never detect (smell) gas or hear gas
escaping at any other time besides refueling. If the
smell of natural gas or a hissing sound is detected at
any time besides refueling, the CNG system should
be shut down. Refer to the Fuel System Shut Down
Procedure.
Only trained and qualified personnel should service
this natural gas vehicle. Components in the fuel
system are under extreme pressure. Severe injury or
death can result from improper service or failure to
follow safety precautions.
Fuel Standards
This vehicle is designed to run on CNG that meets North
American standards, NFPA-52 and SAE J1616 for fuel
composition.
Specications
Momentum Fuel Technologies CNG fuel systems are
available in side mount, back-of-cab, or roof mount, refuse
tail mount configurations. Systems may have one or more
fuel storage cylinders in varying capacities. All systems use
common components with slight variations, depending on
the configuration.
Components
The CNG fuel system consists of the following main
components. (Figure 8)