WOODWARD

PRODUCT LINE OVERVIEW
FUEL LOCKOFFS & FILTERS .
N -VFF-30 Vacuum Fuelock Filter
Fuel Lock . .
REGULATORS & VAPORIZERS .
N-LPR Vapor Regulator .
N-51 Vapor Regulator .1
N-PJ Vapor Regulator .
N-H420-NG Vapor Regulator .
N-J Regulator
N-2001 Regulator/Vaporizer
N-E Regulator .
N-H420 Regulator .
N-H420 Turbo
N-S Regulator
N-L Regulator Repair Kit
Model N-IMP Reduction Valve .
Flow Capacity Chart
CARBURETORS
Model N-CA55-500 Series
Model N-CA70 Series .
Model N-CA100 Series .
Model N-CA 125 Series .
Model N-CA200 Series .
Model N-CA225 Series .
Model N-CA300 Series .
Model N-CA475 Series .
Custom Fit Carburetors .
COMPONENTS .
Throttle Components . .
Air Flow Components .
Hoof Governors .
Century & Zenith .
Primers & Thermostats .
Model Microvac N-1501L Vacuum Safety Switch .
Switches & Gauges .
Hours Meters .
Low Fuel Warning Light .
Hose Components .
Brass Fittings .
Bulkheads, Inline Filters & Sealants .
Tank Fittings & Accessories .
Tank Brackets .
Warning Labels
FORKLIFT KITS .
Introduction .
Caterpillar .
Clark .
Datsun/Nissan . .
Hyster . . .
Komatsu/Mistubishi .
Toyota . .
Yale
Universal Kits . .
TECHNICAL INFORMATION .
Typical Forklift Schematic . .
Automotive Duel Fuel Schematic .
Stationary Engine Schematic . .
Stationary Engine Dual Fuel Schematic .
Standard Dual Fuel Wiring W/ Vacuum, Lift
3-way Vacuum Control Solenoid Duel Fuel Operation . .
Air-Valve Diaphragm Installation .
Fuel Characteristics . . . . .
LPG Fuel Tanks . . . . . .
Carburetor Selection Chart .
Carburetor Position/Bolt Spacing .
Fuel System Adjustment . .
Preliminary Engine Inspection Before Conversion .
Ignition Modifications for LP-Gas .
Engine Starting Problems . .
Maintenance Suggestions & Checks . .
Return Goods Authorization Procedures . .
Order Form . . .
Product Warranty .
PRODUCT LINE OVERVIEW CARBURETORS, REGULATORS & FUELOCKS
2
Typical LPG Fuel System (Items highlighted in boldface blue are shown on the diagram)
Vacuum Fuelock Filter The Streamline carburetion system
starts with the vacuum fuelock filter (VFF). When a slight
vacuum signal from the engine (2h of water column [W.C].) is
sensed by the VFF, the fuel is allowed to flow through a tenmicron
filter to the pressure regulator/vaporizer. When the
vacuum ceases, a spring force pushes on a lever and the
valve operating pin closes against the orifice, thus shutting-off
the fuel flow. Therefore, the vacuum fuelock filter has two
primary functions: (1) it prevents dirty fuel from reaching the
carburetor and (2) it shuts off the fuel flow automatically,
regardless of the ignition being on or off.
Pressure Regulator/Vaporizer Streamline pressure regulators
are categorized as two-stage, negative pressure,
regulator/vaporizers because they:
1. Reduce fuel pressure in two stages,
2. Meter the fuel output in relation to a negative
pressure signal (vacuum) from the carburetors, and
3. Convert the fuel from a liquid to a vapor.
The negative pressure signal from the carburetor acts upon
the secondary diaphragm, allowing atmospheric pressure from
the upper side to move the diaphragm down. This causes the
secondary seat to open; thus allowing fuel to progress from
the primary chamber of the regulator to the secondary
chamber. To assist in engine start-up, some regulator models
have a primer button. These regulators use engine coolant to
assist in vaporizing the fuel via a heat transfer process that
occurs in the vaporizing chamber.
Carburetors The air valve carburetors consist of a mixer,
throttle body and an optional air horn. The air horn enables
the connection of an air hose or air filter assembly. The
throttle valve controls delivery of the air-fuel mixture into the
engine intake manifold based on the operatorfs command
(foot pedal).
The air and fuel are mixed at controlled amounts in the
mixer. The air valve spring pushes the air valve assembly
closed until vacuum from the engine causes the spring to
compress and release fuel. The vacuum signal is transmitted
to the air valve assembly via the communication passages on
the air valve assembly. The greater the vacuum draw from
the engine, the more the air valve spring is compressed and
allows a larger amount of fuel to flow and mix with the air.
The air valve spring begins to compress in the presence of 6h
W.C. of vacuum, and the maximum spring displacement will
occur with 24h W.C. of vacuum.
The air-fuel metering device, or mixer, is completely selfcontained.
It requires no linkage or idle vacuum line from the
engine intake manifold. This construction allows for great
flexibility in the assembly and service of Streamline
carburetors. The mixer has a replaceable air valve assembly.
Fuel systems using air valve carburetors provide triple safety
seals. When the engine is stopped, fuel cannot pass the air
valve because the air valve spring holds the air valve closed.
At the same time, neither the pressure regulator nor the
vacuum fuelock filter allows the fuel flow as there is no
vacuum signal from the engine.
SELECTION CHART WOODWARD
CARBURETOR & REGULATOR SELECTION CHART
The chart below shows the Streamline carburetors and regulators that are available for specific applications. Simply match
your enginefs flow rate (CFM) and/or horsepower (HP) to the model of carburetor and regulator that best suits your needs.
Carburetor models are listed at the bottom of the chart under each set of vertical bars. Regulators, shown at the top of the
chart, are listed according to fuel type: natural gas (NG), compressed natural gas (CNG) and liquified petroleum gas (LPG).
Regulator models N-LPR, N-PJ, N-51, N-J, and N-S can be used with carburetors shown in the white area (left side of chart).
Regulator models N-H420, N-2001, N-EB, and N-H420 can be used with carburetors shown in the blue area (right side of
chart).
For Example: If an industrial engine has 200 CFM of air flow and runs on CNG, then the recommended carburetor would be
Model N-CA200 and the recommended regulator would be Model N-H420. Or, referencing horsepower, a 300 HP industrial
engine running on LPG would use carburetor Model N-CA-475 and any of the regulator Models N-2001, N-EB, or N-H420.
Note that this chart should be used for reference only. To determine the ideal fuel system components for your engine,
contact a Streamline application engineer.
N-CA55 N-CA70 N-CA100 N-CA125 N-CA200 N-CA225 N-CA300 N-CA475
600
550
500
450
400
350
300
250
200
150
100
50
0
200
400
Flow Rate (CFM)
Maximum Engine Power (HP)
Minimum Flow Maximum Flow - Industrial Maximum Flow - Vehicle
0
50
100
150
250
300
350
CARBURETOR AND REGULATOR SELECTION REFERENCE CHART
NG N-LPR
N-PJ
N-51, N-J, N-S
N-H420
N-2001, N-EB, N-H420
CNG
LPG
FUELOCK SPECIFICATIONS
A. Overall Height . . . . . . . . . . . . 49.32" (108.7 mm)
B. Overall Width . . . . . . . . . . . . . 41.2" (114.3 mm)
C. Overall Depth . . . . . . . . . . . . . . 23.4" (69.9 mm)
D. Front of Fuelock to Center of
Mounting Hole . . . . . . . . . . . . . 15.16" (23.8 mm)
E. Mounting Holes Center to Center17.8" (47.6 mm)
F. Mounting Hole Diameter . . . . . . . . . . . . . . 1.4-20
G. Back of Fuelock to Center of
Fuel Outlet . . . . . . . . . . . . . . . 17.16" (36.5 mm)
H. Back of Fuelock to Center of
Vacuum Port . . . . . . . . . . . . . . 11.4" (31.6 mm)
J. Air Valve Vacuum Port NPT . . . . . . 1.8" (3.2 mm)
K. Fuel Outlet NPT . . . . . . . . . . . . . 1.4" (6.35 mm)
L. Fuel Inlet NPT. . . . . . . . . . . . . . . 1.4" (6.35 mm)
M. Vent . . . . . . . . . . . . Accepts 1.8" (3.2 mm) NPT
Model N-VFF30 Series Vacuum Fuelock Filter . 325 HP
Parts Description, Installation & Operation
GENERAL The N-VFF30 is a vacuum operated lockoff designed for
low engine vacuum activation. It also contains a filter to remove
foreign materials from the fuel. It is used with high pressure LPG
vapor or liquid withdrawal, where dependable fuel shut-off is
required. It can be used for many mobile powered applications,
such as forklifts, floor buffers or pressure washers.
WARNING! The N-VFF30 should be installed and maintained per
these instructions and all applicable federal, state, and local laws
and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor applications
by NFPA definition, a regulator is not considered a positive shut-off
valve. An approved automatic shut-off device is required to be
installed. This will shut off the fuel supply should the engine fail
while unattended. Shut-off devices come in vacuum- or solenoidactuated
configurations.
OPERATION The N-VFF30 is a dedicated vacuum operated fuelock
designed to shut-off and release fuel. When engine vacuum ceases,
a spring force causes the valve seat to close, shutting off the fuel.
It is important to remember that fuel should not flow to the engine
when it is not in operation. A properly installed N-VFF30 requires
approximately 2 inches of water vacuum to start the opening
sequence.
INSTALLATION The N-VFF30 should be mounted between the fuel
supply and the vaporizer/regulator and be connected to an available
manifold vacuum source.
SERVICE The N-VFF30 should be periodically checked for leakage.
If the unit requires service, we suggest you take it to a qualified
service technician. If not available, Woodward will furnish a list of
repair facilities or provide service information.
FUEL LOCKOFFS N-VFF30 VACUUM FUELOCK FILTER Information & Dimensions
4
U.L Listed
N-VFF30 Series
. Fuel lock and filter in one unit
. Low (2" W.C.) vacuum signal activation
. Liquid or vapor fuel
. Rated to 312 psi maximum inlet pressure
PARTS LISTING
Item Part No. Description Qty.
1* N00-6443 N-S1-59, Screw, 8-32 x 5.8" SEMS 6 (RK 2)
2 N00-4525 N-C1-37, Cover, Diaphragm 1
3* N00-4723A N-AD1-26, DIAPHRAGM ASSEMBLY, SILICONE 1
4 N00-6404 N-S1-7, Screw 8-32 x 1/4" 2
5 N00-5016 N-F3-2, Fulcrum 1
6 N00-5654 N-L1-39, Lever, Valve Opening 1
7 N00-4230A N-AB1-34, Body Assembly 1
8 N00-6402 N-S1-5, Screw, 1/4-20 x 5/8" SEMS 2
9* N00-7511 N-W1-42, WASHER, SEAL RETAINING 1
10* N00-6735-1 N-S3-42, SEAL, O-RING 1
11* N00-5908 N-P1-15, PIN, VALVE OPERATING 1
12* N00-6806 N-S4-18, SEAT, VALVE 1
13 N00-6623 N-S2-40, Spring, Valve 1
14 N00-6408 N-S1-12, Screw, 8-32 x 5/16" SEMS 1
15* N00-7003 N-S7-3, SCREEN, FILTER BACKUP 1
16* N00-4910 FILTER PAD 1
17* N00-5260 N-G1-89, GASKET, FILTER COVER 1
18* N00-4910A FILTER PAD AND GASKET 1
19 N00-4526 N-C1-38, Cover, Filter 1
20* N00-6478 N-S1-10, SCREW, 12-24 X 3.4" SEMS 7 (RK 2)
* Indicates Repair Kit Components
REPAIR KITS: (Components shown in blue)
N00-6321A N-RKVFF30-2, Repair Kit with Silicone Diaphragm
N00-4910A Item 18, Filter Pad and Gasket only
Parts Listing N-VFF30 VACUUM FUELOCK FILTER FUEL LOCKOFFS
p
Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
Note: Parts in blue are components of Repair Kit
(N-RKVFF30-2).
ORDERING INFO
Check UL
Part No. Model No. Diaphragm Primer Valve Listed
N00-0124A N-VFF30-2 * Silicone .
N00-0125A N-VFF30-2 Silicone .
N00-0126A N-VFF30-2-3 Silicone . .
N00-0128A N-VFF30-2-4 Silicone . . .
N00-0129A N-VFF30-2-5 Silicone . .
(*) Blank Cover
FUEL LOCKOFFS FUEL LOCKS
6
Part No. Description
N3-0225-4 1/8" (3.2 mm) NPT Female Inlet and
Outlet, Self-Grounded
Part No. Description
N3-0173-1 1/4" (6.4 mm) NPT Female Inlet,
1/4" (6.4 mm) Male Outlet
Part No. Description
N3-0343 1/4" (6.4 mm) NPT Female Inlet,
1/4" (6.4 mm) Male Outlet
N3-0343-1 Repair Kit
Part No. Description
N3-0342 1/4" (6.4 mm) NPT Female Inlet,
1/4" (6.4 mm) Male Outlet
N3-0344-1A Repair Kit
Dual Fuel Gasoline Inline Solenoid, 12V
LP-Gas Multi-fuel Shut-off Solenoid Valve, 12V
Inline LP-Gas Filter Shut-off Valve,12V
Inline LP-Gas Multi-fuel Shut-off with Magnet
FUEL LOCKS FUEL LOCKOFFS
phone: 847.967.7730 / 800.451.7040 fax: 815.639.5299 web: www.woodward.com/fsp 7
Part No. Description
N3-0165-2 1/4" (6.4 mm) NPT Female Inlet & Outlet
N3-0148 3/4" (19.1 mm) NPT Female Inlet & Outlet
(Low Pres.)
Part No. Description
N3-0239 Use with N3-0083-1 Vacuum Switch
(see Control Components section)
N3-0220-1 Repair Kit
Part No. Description
N3-0164-2 1/4" (6.4 mm) NPT Female Inlet & Outlet
N3-0362 3/8" (9.5 mm) NPT Female Inlet & Outlet
N3-0183 1/2" (12.7 mm) NPT Female
Inlet & Outlet
LP-Gas Multi-fuel Shut-off Solenoid Valve, 90‹
LP-Gas Multi-fuel Shut-off Solenoid Valve, 180‹, 12V
LP-Gas Electric Filter Shut-off Solenoid Valve
Model N-LPR Series Regulator . 25 HP
GENERAL The N-LPR is designed for sensitivity and simple operation.
It is used with low pressure gaseous fuels, where dependable starting is
required. Because of its extreme sensitivity, the N-LPR offers excellent
results in most remote starting applications (standby power generators,
etc.) if installed and maintained properly. Suitable for engines up to
25 HP.
WARNING! The N-LPR should be installed and maintained per these
instructions and all applicable federal, state, and local laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor applications by
NFPA definition, a regulator is not considered a positive shut-off valve. An
approved automatic shut-off device is required to be installed. This will
shut off the fuel supply should the engine fail while unattended. Shut-off
devices come in vacuum- or solenoid-actuated configurations.
OPERATION The N-LPR is an automatic zero regulator. The engine
creates a vacuum which acts through the outlet of the N-LPR on the
diaphragm. Atmospheric pressure then forces the diaphragm toward the
vacuum, depressing the lever and pulling the valve seat away from the
orifice which allows fuel to flow as long as the demand persists. When
the vacuum ceases, a spring force pushes on the lever and forces the
seat valve against the orifice shutting off the fuel flow. It is important to
remember that fuel should not flow through the N-LPR when the engine is
not running. A properly adjusted N-LPR requires a vacuum of less than
0.35" of water column to start the opening sequence. Due to this
sensitivity, most installations do not need priming to start unless low
cranking speed or restricted and lengthy piping are required.
If priming is necessary and a manual primer is installed, use only
1 or 2 second bursts of fuel and immediately start the engine.
If there is a choke on the carburetor, do not use it as this will probably
cause flooding and hard starting.
INSTALLATION The N-LPR should be mounted as close to the carburetor
as possible with the outlet on top (the arrow on the cover pointing up)
and the diaphragm in a vertical position. This helps to minimize the
effects of gravity on diaphragm travel. The unit should also be placed for
easy access to the primer if provided.
There are two sets of mounting holes provided. Either set of mounts will
adequately support the N-LPR. The bottom set of holes has a 1-3/4"
(44.5 mm) bolt spacing. The mounting bosses on cover are spaced
5-3/4" (146.1 mm) apart for use with 5/16" (7.9 mm) bolts.
Before installing the fuel supply line, be sure that the gas pressure
is no more than the maximum inlet pressure shown on the front of the
N-LPR. If the pressure is greater, leakage could result in a fire hazard
and/or hard starting. The piping to the inlet should be of sufficient size
to allow full fuel flow to the N-LPR. This is very important in natural gas
installations, as any restrictions can affect engine performance.
If a solenoid is used ahead of the N-LPR in the low pressure line,
it should have an orifice at least 7/16" (11.1 mm) in diameter.
Flexible piping to the inlet should be used to prevent cracking from
vibration if the N-LPR is mounted on the engine or other vibrating
surface.
SERVICE The N-LPR should be periodically checked for leakage. If the
unit requires service, we suggest you take it to a qualified service
technician. If not available, Woodward will furnish a list of repair facilities
or provide service information.
REGULATOR SPECIFICATIONS
A. Overall Width . . . . . . . . . . . . . . . . . 61.4" (158.8 mm)
B. Overall Depth . . . . . . . . . . . . . . . . . 35.8" (92.1 mm)
C. Overall Height . . . . . . . . . . . . . . . . 61.2" (165.1 mm)
D, E. Mounting Holes 53.4"; 13.4"
Center to Center . . . . . . . (146.1mm; 44.5 mm)
F. Mounting Holes
Distance from Center . . . . . . . . . . . 121.32" (42.1 mm)
G. Air Vent NPT . . . . . . . . . . . . . . . . . . . . 1.8" (3.2 mm)
H. Vapor Fuel Inlet NPT. . . . . . . . . . . . . 3.4" (19.1 mm)
J. Vapor Fuel Outlet NPT . . . . . . . . . . . . . 3.8" (9.5 mm)
K. Test Port NPT . . . . . . . . . . . . . . . . . . . 1.8" (3.2 mm)
REGULATORS N-LPR VAPOR REGULATOR Information & Dimensions
8
U.L. Listed
K
. Sensitive, low pressure vapor regulator with
precise break-off setting
. 11" W.C. (6 oz.) maximum inlet pressure
N-LPR Series
PARTS LISTING
Item Part No. Description Qty.
1* N-C11-1 CAP, ADJ. SCREW, TR 1
2 N-S2-18 Screw, Lock, Adj. Spring 1
3 N-S2-11-LPR Screw, Pressure Adjustment 1
4 N-J1-3 Jet 1
5* N-W1-6 SEAL, JET 1
6* N-S3-14 SPRING 1
7 N2-1011 Plug, 1.8 NPT, Slotted Head 1
8 N-B1-3-LPR Standard Body 1
9* N-S5-1 SEAT 1
10* N-W1-5-LPR WASHER, SEAT BACKUP 1
11 N-L1-5A Lever Assembly 1
12 N-P1-11-LPR Pin, Lever Fulcrum 1
13 N-S10-11 Screw, #4-40 x 1.4" Pan Head 2
14 N-P1-12 Pin, Connector 1
15* N-D1-7A DIAPHRAGM ASSEMBLY, SILICONE 1
16 N00-7505 N-W1-27, Washer, Primer 1
17 N-C1-7-LPR Cover, Back 1
18 N-S2-21-LPR Spring, Primer 1
19 N-R11-2 Pin, Primer 1
20* N00-6400 SCREW, 10-24 X 5/8" SLOTTED 6
FILISTER HEAD WITH SPLIT (RK4)
LOCKWASHER, SEMS
* Indicates Repair Kit Components
REPAIR KIT: (Components shown in blue)
N-RK-LPR Repair Kit with Silicone Diaphragm
Parts Listing N-LPR VAPOR REGULATOR REGULATORS
p
Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
Note: Parts in blue are components of Repair Kit
(N-RK-LPR).
ORDERING INFO
Maximum Tamper- UL
Part No. Inlet Pressure Resistant Primer Listed
N-LPR-1A 11" WC (6 oz.) . .
N-LPR-2A 11" WC (6 oz.) . .
N-LPR-3A 11" WC (6 oz.) . . .
N-LPR-4A 11" WC (6 oz.) .
Model N-51 . 25 HP
Parts Description, Installation & Operation
GENERAL The N-51 is designed for sensitivity and simple operation. It is
used with high pressure propane vapor in applications up to 25 HP.
Because of its compactness, it offers excellent results in most mobile
equipment applications.
WARNING! The N-51 should be installed and maintained per these
instructions and all applicable federal, state, and local laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor applications by
NFPA definition, a regulator is not considered a positive shut-off valve.
An approved automatic shut-off device is required to be installed. This
will shut off the fuel supply should the engine fail while unattended.
Shut-off devices come in vacuum- or solenoid-actuated configurations.1
OPERATION LP-gas vapor enters the primary chamber and is then
reduced from the tank pressure to about 4 psi.2 As negative pressure is
transmitted from the carburetor to the regulator, the regulator will allow
fuel to be drawn into the carburetor. Some N-51 models are equipped
with an idle circuit that allows for adjustment of the fuel mixture at low
engine speeds. Some regulators are equipped with a primer button.
Correctly installed regulator should not require priming. If priming is
required, a maximum duration of only 1 second should be used.
INSTALLATION The N-51 should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the lowest position
for best flow.
SERVICE The N-51 should be periodically checked for leakage. If the
unit requires service, we suggest you take it to a qualified service
technician. If not available, Woodward will furnish you a list of repair
facilities or provide service information.
N-51 Series
REGULATOR SPECIFICATIONS
A. Overall Height. . . . . . . . . . 53.8" (136.5mm)
B. Overall Depth . . . . . . . . . . . 35.8" (92.1mm)
C. Overall Width . . . . . . . . . . 53.8" (136.5mm)
D. Back of Regulator to Center of
Vapor Fuel Inlet/Outlet . . . . 15.16" (33.3mm)
E. Mounting Holes Center . . . . 4.73"; 1.024"
To Center (2) Locations (120mm; 26mm)
F. Fuel Inlet NPT. . . . . . . . . . . . . 1.4" (6.4mm)
G. Vacuum Port NPT . . . . . . . . 1.8" (3.2 mm)
H. Primary Test Port NPT . . . . . . 1.8" (3.2mm)
J. Vent/Balance Line . . . . . . . . . . . . . . . . N/A
K. Vapor Fuel Outlet NPT . . . . . . 3.8" (9.5mm)
REGULATORS N-51 VAPOR REGULATOR Information & Dimensions
10
U.L Listed*
J
C
K
ORDERING INFO
Idle Vacuum No. Of UL
Part No. Circuit Lockoff Primer Mounting Ears Listed*
N-51A . . 2 .
N-51A-C . . 1 .
N-51-1A . . 2 .
N-51-1A-C . . 1 .
N-51-2A . . . 2 .
N-51-2A-C . . . 1 .
N-51-3A . 2
N-51-3A-C . 1
N-51-4A 2
N-51-4A-C 1
N-51-5A . 2
N-51-5A-C . 1
N-51-6A . . 2
N-51-6A-C . . 1
. LP vapor withdrawal regulator
. Primary pressure setting may be specified
to meet engine displacement requirements
. Adjustable idle circuit with internal
lock off available
. Ideal for indoor mobile maintenance
equipment applications
PARTS LISTING
Item Part No. Description Qty.
1 N-C2-3 Cap, Tamper Resistant 1
2 N-R2-2 Retainer, Spring 1
3* N-S2-5 SCREW, COVER, 10-32 X 5.8" SEMS 6 (RK 4)
3B* N-S2-5T SCREW, COVER, 10-32 X 5.8" TAMPER RESISTANT 4 (RK 2)
4 N-C1-4-1 Cover, Primary 1
5 N-S3-8 Spring, Primary 1
6* N-G1-3 GASKET, PRIMARY 1
7* N-D1-6A DIAPHRAGM ASSEMBLY, PRIMARY 1
8 N-S2-4 Screw, Lever Bridge, 10-32 x 5/16" SLFH 2
9 N-B2-1 Bridge, Primary Lever 1
10 N-P1-5 Pin, Primary Lever 1
11* N-L1-2 LEVER, PRIMARY 1
12* N-V1-4 VALVE, SECONDARY SEAT 2
13 N-S3-7 Spring, Primary Lever 1
14 N00-6104 Plug, 1.8" NPT, Hex Head 1
15 N00-6402 Screw, 1.4-20 x 9/16" SEMS 2
16 N-B1-2A Body Assembly 1
17 N-S3-9 Spring, Vacuum Lock 1
18* N-D1-4A DIAPHRAGM ASSEMBLY, VACUUM LOCK 1
19 N-R3-1 Ring, Vacuum Lock 1
20 N-S2-6 Screw, Vacuum Lock Ring, 10-32 x 3/8" 4
Slotted Pan Head
21 N-S3-12-2 Spring, Secondary Lever 1
22 N-S2-10 Screw, Secondary Lever, 10-32 x 1/4" 2
Slotted Pan Head
23* N-L1-3A LEVER ASSEMBLY, SECONDARY 1
24 N-P1-10 Pin, Secondary Lever 1
25* N-D1-5A DIAPHRAGM ASSEMBLY, SECONDARY 1
26* N-C2-2 CAP, TAMPER RESISTANT FOR IDLE SCREW 1
27 N-S2-8 Screw, Idle Adjustment (Part of Item 28) 1
28 N-C1-5A Cover Assembly, Secondary 1
N-C1-5A-1 Cover Assembly, Sec., with Primer
N-C1-5A-C Cover Assembly, Sec., One Mounting Ear
N-C1-5A-1C Cover Assembly, Sec., w/ Primer, One Mounting Ear
* Indicates Repair Kit Components
REPAIR KIT: (Components shown in blue)
N-RK-51A
Parts Listing N-51 VAPOR REGULATOR REGULATORS

1. Although some N-51 models are equipped with an internal lockoff to override the idle circuit, this
is not considered a positive shut-off valve per NFPA pamphlet 58.
2. Alternate primary pressure settings are available to meet engine displacement requirements,
ranging from 2.5 psi to 4.5 psi, in 0.5 psi increments. To order primary pressure other than 4.0 psi
add as a suffix to the part number. Ex. N-51A-C-3.0
Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
Note: Parts in blue are components of Repair Kit
(N-RK-51A).
ORDERING INFO
Part No. Description
N00-0027A N-PJ, CNG Regulator,
Silicone Diaphragm
N00-0027A
REGULATOR SPECIFICATIONS
A. Overall Height . . . . . . . . . . . . . 43.8" (111.1 mm)
B. Overall Depth . . . . . . . . . . . . . 313.16" (96.8 mm)
C. Overall Width. . . . . . . . . . . . . . 45.8" (117.5 mm)
D. Back of Regulator to Center of
Vapor Fuel Outlet . . . . . . . . . . . 15.8" (41.3 mm)
E. Back of Regulator to Center of
Water Outlet . . . . . . . . . . . . . . . 13.8" (34.9 mm)
F. Mounting Holes
Center to Center. . . . . . . . . . . . . 15.8" (41.3 mm)
G. Coolant Inlet & Outlet NPT . . . . . . 3.8" (9.5 mm)
H. Vapor Fuel Inlet NPT. . . . . . . . . . . 1.4" (6.4 mm)
J. Primary Test Port NPT . . . . . . . . . . 1.8" (3.2 mm)
K. Vapor Fuel Outlet NPT. . . . . . . . . 1.2" (12.7 mm)
L. Vent/Balance Line Connect NPT . . 1.8" (3.2 mm)
Model N-PJ (CNG) . 100 HP
Parts Description, Installation & Operation
GENERAL The N-PJ type regulator is a two-stage positive
pressure regulator for CNG applications up to 100 HP output.
WARNING! The N-PJ should be installed and maintained per
these instructions and all applicable federal, state, and local
laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not considered a
positive shut-off valve. An approved automatic shut-off device is
required to be installed. This will shut off the fuel supply should the
engine fail while unattended. Shut-off devices come in vacuum- or
solenoid-actuated configurations.
IMPORTANT NOTE: The N-PJ is rated to 312 psi inlet pressure. In
CNG applications (where tank pressure may exceed 3000 psi) a
separate high-pressure regulator must be installed between the
tank and the N-PJ to reduce the incoming pressure below 312 psi.
OPERATION The low pressure N-JP regulator is a positive pressure
output, two-stage regulator. The unit reduces the compressed
natural gas received from the high pressure regulator to an outlet
pressure slightly above atmospheric pressure.
INSTALLATION The N-PJ should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the lowest
position for best flow.
SERVICE The N-PJ should be periodically checked for leakage.
If the unit requires service, we suggest you take it to a qualified
service technician. If not available, Woodward will furnish a list of
repair facilities or provide service information.
REGULATORS N-PJ VAPOR REGULATOR Information & Dimensions
12
L
. Positive pressure regulator for natural gas, CNG
and LP applications
. Rated to 312 psi maximum inlet pressure
PARTS LISTING
Item Part No. Description Qty.
1* N00-6443 N-S1-59, SCREW, 8-32 X 5.8" SEMS 6 (RK2)
2 N00-6416 N-S1-22, Screw, 6-32 x 1/4" SEMS 4
3 N-C2-4 Cap, Spring Retainer 1
4 N-S2-9 Screw, Spring Retainer 1
5 N-N1-1 Nut, Spring Housing 1
6 N00-5255 Gasket, Spring Retainer 1
7 N00-7004 N-S7-4, Screen, Atmospheric Vent 1
8 N00-4523-2 N-AC1-34-3, Cover Assembly, Secondary 1
9 N-S3-6 Spring, Positive Pressure 1
10* N00-4733A N-AD1-26-2, DIAPHRAGM ASSEMBLY, SILICONE 1
11* N00-6434 N-S1-42, SCREW 8-32 X 3.8" SEMS 1
12 N00-5651 N-L1-37, Lever, Secondary Regulator 1
13 N00-5904 N-P1-8, Pin, Secondary Fulcrum 1
14* N00-6812 N-S4-27, SEAT, SECONDARY REGULATOR 1
15 N00-4229A N-AB1-33, Body Assembly 1
16 N00-6402 N-S1-5, Screw, 1/4-20 x 5/8" SEMS 2
17 N00-6105 N-P3-14, Plug 1.2" NPT 1
18* N00-6804 N-S4-16, SEAT, PRIMARY REGULATOR 1
19* N00-5256 N-G1-85, GASKET, BODY TO PLATE 1
20 N00-6009 N-P2-26, Plate, Converter Body Cover 1
21 N00-6104 N-P3-13, Plug, 1.8" Pipe, Hex Head 1
22 N00-6711 N-S3-15, Spring, Primary Valve 1
23* N00-5907 N-P1-14, PIN, PRIMARY VALVE 1
24* N00-4717A N-AD1-22, DIAPHRAGM ASSEMBLY, PRIMARY 1
25 N00-4521 N-C1-33, Cover, Primary Regulator 1
26* N00-6406 N-S1-10, SCREW, 8-32 X 1" SEMS 7 (RK2)
* Indicates Repair Kit Components
REPAIR KIT: (Components shown in blue)
N00-6315A N-RK-PJ, Repair Kit with Silicone Diaphragm
Parts Listing N-PJ VAPOR REGULATOR REGULATORS

Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
Note: Parts in blue are components of Repair Kit
(N-RK-PJ).
N-H420-NG
REGULATOR SPECIFICATIONS
A. Overall Width . . . . . . . . . . . 57.10" (144.8 mm)
B. Overall Length . . . . . . . . . . 57.10" (144.8 mm)
C. Depth (N-H420-SNGA). . . . 49.10" (124.5 mm)
D. Depth (N-H420-SONGA) . . 49.10" (124.5 mm)
E. Mounting Holes
Center to Center. . . . . . . . . . 222.25" (73.2 mm)
F. Mounting Screws (4). . . . . . . . . . . . 1.4-20 x 5.8"
G. Fuel Outlet NPT . . . . . . . . . . . . 1" (25.4 mm)
H. Fuel Inlet NPT . . . . . . . . . . . . . . 1.4" 6.4 mm)
J. Coolant Inlet and Outlet NPT . . . 3.8" (9.5 mm)
Model N-H420-NG
Parts Description, Installation & Operation
GENERAL The N-H420-NG regulator is designed for use with stationary
engines fueled by natural gas, or in on-highway applications fueled by
compressed natural gas (CNG).
WARNING! The N-H420-NG should be installed and maintained per
these instructions and all applicable federal, state, and local laws
and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor applications
by NFPA definition, a regulator is not considered a positive shut-off
valve. An approved automatic shut-off device is required to be
installed. This will shut off the fuel supply should the engine fail
while unattended. Shut-off devices come in vacuum- or solenoidactuated
configurations.
IMPORTANT NOTE: The N-H420-NG is rated to 250 psi inlet pressure.
In CNG applications (where tank pressure may exceed 3000 psi) a
separate high-pressure regulator must be installed between the tank
and the N-H420-NG to reduce the incoming pressure below 250 psi.
OPERATION Natural gas enters the regulator primary chamber and the
pressure of the incoming gas is reduced to approximately 1.5 psi.
The zero governor N-H420-NG will not pass fuel without a vacuum
signal from the carburetor. Its orange secondary spring (N-S3-3)
requires approximately -0.5" of water column to initiate fuel flow.
The positive pressure N-H420-NG works well in venturi applications
where the vacuum signal to the regulator outlet may be weak at low
engine speeds. It will flow fuel at a volumetric rate of approximately
1 CFM with the outlet at atmospheric pressure. Flow is interrupted
when approximately 8 inches of water backpressure is developed at the
outlet.
INSTALLATION The N-H420-NG should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the lowest position
for best flow.
SERVICE The N-H420-NG should be periodically checked for leakage.
If the unit requires service, we suggest you take it to a qualified service
technician. If not available, Woodward will furnish a list of repair
facilities or provide service information.
REGULATORS N-H420-NG VAPOR REGULATOR Information & Dimensions
14
. Mounts vertically or horizontally
. Positive pressure version flows fuel at 1.0 CFM
with outlet at atmospheric pressure
. Zero governor version with orange secondary
spring initiates fuel flow at -0.5 inches of
water column
PARTS LISTING
Item Part No. Description Qty.
1 N00-6416 Screw . N-S1-22, 6-32 X 1/4" (N-H420-SNGA only) 4
2 N-C2-4 Cap . Spring Retainer (N-H420-SNGA only) 1
3 N-S2-9 Screw . Spring Adjust (N-H420-SNGA only) 1
4 N-N1-1 NUT . Spring Adjust (N-H420-SNGA only) 1
5 N00-6443 SCREW . N-S1-59 COVER, 8-32 X 5/8" SEMS 8 (RK 4)
6 N00-5255 Gasket . N-G1-84, Spring Cap (N-H420-SNGA only) 1
7 N00-7004 Screen . Secondary Vent 1
8 N-C1-1-1 Cover . Secondary (N-H420-SNGA only) 1
N-C1-1 Cover . Secondary (N-H420-SONGA only) 1
9 N-S3-6 Spring . Positive Pressure (N-H420-SNGA only) 1
10* N-D1-2A DIAPHRAGM ASSEMBLY, SECONDARY, SILICONE 1
11 N00-6443 Screw . N-S1-59 Cover, 8-32 X 5/8" SEMS 8
12 N-P1-2 Pin . Secondary Lever Fulcrum 1
13 N-L1-1 Lever . Secondary 1
14* N-V1-1A VALVE . SECONDARY 1
15 N-S3-3 Spring, Secondary Orange (N-H420-SONGA only) 1
16 N-C1-2 Cover . Primary Diaphragm 1
17 N-S3-4 Spring . Primary Regulator 2
18* N-D1-3A DIAPHRAGM ASSEMBLY, PRIMARY 1
19 N00-6104 Fitting . 1/8" NPT Hex Pipe Plug 1
20 N-B1-1CA Body . Sub-Assembly 1
21 N-P1-3 Pin . Primary Valve Operating 1
22* N-G1-1 GASKET . GAS & WATER CHAMBER 1
23 N-C1-3 Cover . Gas & Water Chamber 1
24 N-V1-2A VALVE . PRIMARY 1
25 N-S3-5 Spring . Primary Seat 1
26 N-O1-1 O-RING . LP-GAS INLET 1
27 N-P3-2 Plug . LP-GAS Inlet 1
28* N00-6400 SCREW . N-S1-3, COVER, 10/24 X 5/8" SEMS 12 (RK 2)
29 N00-6402 Screw . 1/4-20 UNC-2A X 5/8" Hex 4
* Indicates Repair Kit Components
REPAIR KIT: (Components shown in blue)
N-RKH420SA Repair Kit with Silicone Diaphragm
ORDERING INFO
Part No. Description
N-H420-SNGA Natural Gas Regulator, Adjustable
Positive Pressure
N-H420-SONGA Natural Gas Regulator, Zero Governor
w/ Orange Spring (-0.5" WC)
Parts Listing N-H420-NG VAPOR REGULATOR REGULATORS
Note: Parts in blue are
components of Repair
Kit (N-RKH420SA).
N-J Series
REGULATOR SPECIFICATIONS
A. Overall Height . . . . . . . . . . . . . 43.8" (111.1 mm)
B. Overall Depth . . . . . . . . . . . . . . . 3" (76.2 mm)
C. Overall Width. . . . . . . . . . . . . . 45.8" (117.5 mm)
D. Back of Regulator to Center of
Vapor Fuel Outlet . . . . . . . . . . . 15.8" (41.3 mm)
E. Back of Regulator to Center of
Water Outlet . . . . . . . . . . . . . . . 13.8" (34.9 mm)
F. Mounting Holes
Center to Center. . . . . . . . . . . . . 15.8" (41.3 mm)
G. Coolant Inlet & Outlet NPT . . . . . . 3.8" (9.5 mm)
H. Liquid Fuel Inlet NPT . . . . . . . . . . 1.4" (6.4 mm)
J. Primary Test Port NPT . . . . . . . . . . 1.8" (3.2 mm)
K. Vapor Fuel Outlet NPT. . . . . . . . . 1.2" (12.7 mm)
L. Vent/Balance Line Connect NPT . . 1.8" (3.2 mm)
Model N-J . 100 HP
Parts Description, Installation & Operation
GENERAL The N-J type regulator is an LPG liquid withdrawal
high pressure regulator. This regulator provides excellent fuel
delivery with liquid-cooled engines up to 100 HP.
WARNING! The N-J should be installed and maintained per
these instructions and all applicable federal, state, and local
laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not considered
a positive shut-off valve. An approved automatic shut-off
device is required to be installed. This will shut off the fuel
supply should the engine fail while unattended. Shut-off
devices come in vacuum- or solenoid-actuated configurations.
OPERATION Liquid propane enters the regulator and then is
vaporized using heat from the enginefs coolant. Tank pressure
is reduced to approx. 1.5 psi. As negative pressure is
transmitted from the carburetor to the regulator, the regulator
releases propane vapor to the carburetor. Some regulators are
equipped with a primer button. Correctly installed regulator
should not require priming. If priming is required, a maximum
duration of only 1 second should be used.
INSTALLATION The N-J should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the
lowest position for best flow.
SERVICE The N-J should be periodically checked for leakage.
If the unit requires service, we suggest you take it to a
qualified service technician. If not available, Woodward will
furnish a list of repair facilities or provide service information.
REGULATORS N-J VAPORIZER/REGULATOR Information & Dimensions
16
U.L Listed ő
L
. Propane liquid withdrawal vaporizing regulator
. For liquid-cooled engines up to 100 HP
. Ideal for mobile industrial
equipment applications
. Rated to 312 psi maximum inlet pressure
PARTS LISTING
Item Part No. Description Qty.
1* N00-6443 N-S1-59, SCREW, 8-32 X 5.8" SEMS 6 (RK2)
2 N00-7004 N-S7-4, Screen, Atmospheric Vent 1
(Part of Item 3)
3 N00-4523A N-AC1-34, Cover Assembly, Secondary: 1
(N-C1-34, N-S2-21, N-W1-27, N-S7-4)
4 N00-7505 N-W1-27, Washer, Hand Primer 1
(Part of Item 3)
5* N00-4722A N-AD1-26, DIAPHRAGM ASSEMBLY,
SECONDARY, SILICONE 1
6* N00-6434 N-S1-42, SCREW, 8-32 X 3.8" SEMS 1
7 N00-5651A N-AL1-37, Lever Assembly, Secondary Regulator 1
8 N00-5904 N-P1-8, Pin, Secondary, Fulcrum 1
9* N00-6812 N-S4-27, SEAT, SECONDARY REGULATOR 1
10* N00-6618** N-S2-35, SPRING, BLUE SECONDARY 1
N00-6621** N-S2-38, SPRING, ORANGE SECONDARY 1
11 N00-4229A N-AB1-33, Body Assembly 1
12 N00-6402 N-S1-5, Screw 1.4-20 x 5/8" SEMS 2
13 N00-6105 N-P3-14, Plug 1/2 NPT 1
14* N00-6804 N-S4-16, SEAT, PRIMARY REGULATOR 1
15* N00-5256 N-G1-85, Gasket, Body to Plate 1
16 N00-6009 N-P2-26, Plate, Converter Body Cover 1
17 N00-6104 N-P3-13, Plug 1.8" Pipe, Hex Head 1
18 N00-6711 N-S2-36, Spring, Primary Valve 1
19* N00-5907 N-P1-14, PIN, PRIMARY VALVE 1
20* N00-4717A N-AD1-22, DIAPHRAGM ASSEMBLY, PRIMARY 1
21 N00-4521 N-C1-33, Cover, Primary Regulator 1
22* N00-6406 N-S1-10, SCREW, 8-32 X 1" SEMS 7 (RK2)
* Indicates Repair Kit Components
** Two outlet fuel flow initiation pressures are available. Orange secondary spring (N00-6621)
requires approximately -0.5" of water column to initiate fuel flow. Blue secondary spring
(N00-6618) requires approximately -1.5" of water column.
REPAIR KIT: (Components shown in blue)
N00-6313A N-RK-J-2, Repair Kit with Silicone Diaphragm
Blue and Orange Secondary Springs
Parts Listing N-J VAPORIZER/REGULATOR REGULATORS

Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
ő See ordering info chart for U.L. Listed models.
Note: Parts in blue are components of Repair Kit
(N-RK-J-2).
ORDERING INFO
Vacuum Check Inline UL
Part No. Model No. H2O Spring Diaphragm Primer Valve Filter Listedő
N00-0005A N-JB-2 1.5 Blue Silicone .
N00-0009A N-JB-2 1.5 Blue Silicone .
N00-0010A N-JO-2* 1.5 Blue Silicone .
N00-0014A N-JO-2 0.5 Orange Silicone .
N00-0024A N-JO-C734 0.5 Orange Silicone . . .
N00-0040A N-JB-L549 1.5 Blue Silicone . . .
(*) Blank Cover
UL Listed
F
C
D
E
G
. Mounts vertically or horizontally
. Designed for use in closed-loop certified systems
. Propane liquid withdrawal vaporizing regulator
. Internally vented (primary diaphragm is
referenced to sedondary chamber pressure)
. For liquid-cooled engines up to 150 HP
. Designed for use in closed-loop certified systems
of mobile industrial equipment
. Rated to 312 psi maximum inlet pressure
REGULATOR SPECIFICATIONS
A. Overall Height . . . . . . . . . . 51/5" (132.1 mm)
B. Overall Width . . . . . . . . . . . 44/5" (121.9 mm)
C. Overall Depth . . . . . . . . . . . . 4" (101.6 mm)
D. Mounting Holes
Center to Center . . . . . . . . . 21/10" (53.3 mm)
E. Fuel Outlet NPT . . . . . . . . . . . 1/2" (12.7 mm)
F. Coolant Inlet and Outlet NPT . . 1/4" (6.4 mm)
G. Fuel Inlet NPT . . . . . . . . . . . . . 1/4" (6.4 mm)
N-2001 Vaporizer/Regulator for LPG-fueled engine
.150 HP
GENERAL The N-2001 two-stage regulator is an LPG liquid
withdrawal high-pressure regulator with an integrated heat
exchanger vaporizer. It provides excellent fuel delivery with
liquid-cooled engines up to 150 HP.
WARNING! The N-2001 should be installed and maintained
per these instructions and all applicable federal, state, and
local laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not considered
a positive shut-off valve. An approved automatic shut-off
device is required to be installed. This will shut off the fuel
supply should the engine fail while unattended. Shut-off
devices come in vacuum- or solenoid-actuated configurations.
OPERATION Liquid propane enters the regulator primary
chamber and is vaporized using heat from the enginefs
coolant. Tank pressure is reduced to approximately 1.5 psi.
As negative pressure is transmitted from the carburetor to the
regulator, the secondary diaphragm depresses the secondary
lever and the regulator releases propane vapor to the
carburetor. The red secondary spring (N-S11-10) requires
approximately -1.0" of water column to initiate fuel flow.
INSTALLATION The N-2001 should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the lowest
position for best flow. If mounted horizontally, the secondary
cover must face up.
SERVICE The N-2001 should be periodically checked for
leakage. If the unit requires service, we suggest you take it to
a qualified service technician. If not available, Woodward will
furnish a list of repair facilities or provide service information.
REGULATORS N-2001 VAPORIZER/REGULATOR Information & Dimensions
18
N-2001
B
A
4

PARTS LISTING
Part Order No. Description Qty.
1* N00-6443 N-S1-59, COVER SCREW, 8-32 X 5/8" SEMS 4 (RK 2)
2* 1031-1158 T-15, 8-32 X 5/8" TORX TAMPER RESISTANT 2
3* 1012-939 LOCK WASHER, #8 INTERNAL TOOTH 2
4 N-C10-1-1 Secondary Cover 1
5* N-D10-1A SECONDARY DIAPHRAGM ASSEMBLY 1
6 N-S10-2 Pan Head Screw, #10-24 x 1/4" w/Star Washer 1
7 N-L10-3 Secondary Lever 1
8* N-V1-1A SECONDARY VALVE 1
9 N-P10-1 Secondary Lever Fulcrum Pin 1
10* N-S11-10 RED SECONDARY SPRING 1
11 N-L10-1 Pilot Valve Lever 1
12 N-P10-1-1 Pilot Valve Lever Fulcrum Pin 1
13 N-S10-10 Internal Hex Head Set Screw, #8-32 x 1/4" 1
14* NOO-6413 N-S1-19, COVER SCREW, 12-24 X 5/8" SEMS 6 (RK 2)
15 N-C10-3 Primary Diaphragm Cover 1
16 N-S11-1 Primary Regulator Spring 2
17* N-D1O-2A PRIMARY DIAPHRAGM ASSEMBLY 1
18 N00-6104 Fitting, 1/8 NPT Hex Pipe Plug 1
19 N-B10-1A Body Assembly 1
20* N-O10-4 BODY SEAL O-RING 1
21* N-G10-1-1 BODY GASKET 1
22 N-P11-1-1 Regulator Back Plate 1
23* N-O10-1 PRIMARY SEAL O-RING 1
24* N-V10-1 PRIMARY REGULATOR VALVE 1
25* N00-6413 N-S1-19, COVER SCREW, 12-24 X 5/8" SEMS 6 (RK 2)
26* N-O1-1 INLET SEAL O-RING 1
27 N-P3-2 Inlet Plug 1
28 N00-6402 Screw, 1/4-20 UNC-2A X 5/8" Hex Head, SEMS 2
* Indicates repair kit components
REPAIR KIT (Components shown in blue)
N-RK2001-RSA Repair Kit w/ Silicone Diaphragm
Parts Listing N-2001 VAPORIZER/REGULATOR REGULATORS
phone: 847.967.7730 / 800.451.7040 fax: 815.639.5299 web: www.woodward.com/fsp 19
Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
ORDERING INFO
Part No. Description
N-2001-RSA N-2001 Regulator, Red Spring, w/
Silicone Diaphragm (U.L. Listed)
1
Note: Parts in blue are components of
Repair Kit (N-RK2001-RSA)
3
2
N-EB-2 Series
REGULATOR SPECIFICATIONS
A. Overall Height . . . . . . . . . . . . 71.4" (184.2 mm)
B. Overall Depth . . . . . . . . . . . . . 4" (101.6 mm)
C. Back of Converter to Center
of Vapor Fuel Outlet . . . . . . . . . 2" (50.8 mm)
D. Back of Converter to Center
of Water Outlet . . . . . . . . . . . . . 1" (25.4 mm)
E. Mounting Holes,
Center-to-Center . . . . . . . . . . 65.8" (168.3 mm)
F. Mounting Hole Diameter . . . . . . 9.32" (7.1 mm)
G. Coolant Inlet & Outlet NPT . . . . . 3.8" (9.5 mm)
H. LPG Fuel Inlet NPT . . . . . . . . . . 1.4" (6.4 mm)
J. Secondary Accessory Port NPT. . 1.8" (3.2 mm)
K. Primary Test Port NPT . . . . . . . . 1.8" (3.2 mm)
L. Vapor Fuel Outlet NPT . . . . . . . 1" (25.4 mm)
M. Vent/Balance Line
Connection NPT . . . . . . . . . . . . 1.8" (3.2 mm)
Model N-EB-2 Series Regulators For LP-Gas . 400 HP
Parts Description, Installation & Operation
GENERAL The N-E regulator is an LPG liquid withdrawal high
pressure regulator. This regulator provides excellent fuel
delivery with liquid-cooled engines up to 400 HP.
WARNING! The N-E should be installed and maintained per
these instructions and all applicable federal, state, and local
laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not
considered a positive shut-off valve. An approved automatic
shut-off device is required to be installed. This will shut
off the fuel supply should the engine fail while unattended.
Shut-off devices come in vacuum- or solenoid-actuated
configurations.
OPERATION Inside the N-E regulator, liquid propane enters the
regulator and then is vaporized using heat from the engine's
coolant. Tank pressure is reduced to approximately 1.5 psi.
As negative pressure is transmitted from the carburetor to the
regulator, the regulator releases propane vapor to the
carburetor. N-E regulators are equipped with a primer button.
A correctly installed regulator should not require priming. If
priming is required, a maximum duration of only 1 second
should be used.
INSTALLATION The N-E should be mounted as close to the
carburetor as possible, with the fuel outlet placed in the
lowest position for best flow.
SERVICE The N-E should be periodically checked for leakage.
If the unit requires service, we suggest you take it to a
qualified service technician. If not available, Woodward will
furnish a list of repair facilities or provide service information.
REGULATORS N-E VAPORIZER/REGULATOR Information & Dimensions
20
. Propane liquid withdrawal vaporizing regulator
. For liquid-cooled engines up to 400 HP
. -1.5" W.C. fuel initiation (break-off) pressure
. Rated to 312 psi maximum inlet pressure
PARTS LISTING
Item Part No. Description Qty.
1* N00-6400 N-S1-3, SCREW, 10-24 X 5.8" SEMS 8 (RK3)
2 N00-7002 N-S7-1, Screen, Atmospheric Vent 1
3 N00-4509 N-ACI-22-1, Cover Assembly, 1
Secondary: with Primer Button
4 N00-7505 N-W1-27, Washer, Hand Primer 1
5* N00-4718A N-AD1-23, DIAPHRAGM ASSEMBLY, 1
SECONDARY, SILICONE: N-D1-23, N-P22-14,
N-P2-14 (2), N-L2-1, N-R2-3 (2)
6* N00-5681 N-L1-86A, LEVER, SILICONE 1
7 N00-5903 N-P1-7, Pin, Secondary Lever Fulcrum 1
8 N00-6610** N-S2-22, Spring, Secondary Regulator, (Blue) 1
-1.5" W.C.
9* N00-6820 N-S4-37, SEAT, SECONDARY 1
10* N00-6431 N-S1-39, SCREW, 12-24 X 7.8" SEMS 7 (RK2)
11* N00-6432 N-S1-40, SCREW, 10-24 X 3.8" SEMS 2
12 N00-4506 N-C1-20, Cover, Primary Diaphragm 1
13 N00-6604 N-S2-13, Spring, Primary Regulator 2
14* N00-4709A N-AD1-15, DIAPHRAGM ASSEMBLY, PRIMARY: 1
N-D1-15, N-P2-16, N-P2-17, N-R2-3 (3)
15* N00-5906 N-P1-11, PIN, PRIMARY VALVE 2
16 N00-4216 N-AB1-20, Body, Regulator: N-B1-20, N-J1-13 1
17 N00-6104 N-P3-13, Plug, 1.8" Pipe, Hex Head 2
18* N00-5225 N-G1-37, GASKET, REGULATOR BODY 1
19* N00-5015 N-F3-1, SPONGE 1
20* N00-6801 N-S4-7, SEAT, PRIMARY 1
21 N00-4212 N-AB1-19-1, Body Assembly, Heat Exchanger: 1
N-B1-19-1, N-J1-9
22* N00-5224 N-G1-35, GASKET, HEAT EXCHANGER COVER 1
23 N00-4507 N-C1-21, Cover, Heat Exchanger 1
24* N00-6400 N-S1-3 SCREW, 10-24 X 5.8" SEMS 6 (RK3)
* Indicates Repair Kit Components
** Blue secondary spring (N00-6610) requires approximately negative 1.5 inches of water outlet fuel
flow initiation pressure.
REPAIR KIT: (Components shown in blue)
N00-6301A N-RK-E-2, Repair Kit with Silicone Diaphragm
Parts Listing N-E VAPORIZER/REGULATOR REGULATORS

Note: While only certain parts are available for purchase, all parts are listed for reference purposes.
Note: Parts in blue
are components of
Repair Kit (N-RK-E-2).
ORDERING INFO
Part No. Description
N00-0001A N-EB-2 Regulator w/
Silicone Diaphragm
N-H420 Series
REGULATOR SPECIFICATIONS
A. Overall Width . . . . . . . . . . . 511.16" (144.5 mm)
B. Overall Depth . . . . . . . . . . . 41.8" (104.8 mm)
C. Mounting Holes
Center to Center 27.8" x 27.8" (73 mm x 73 mm)
D. Mounting Hole Diameter . . . . . . . . . 1.4"-20 (4)
E. Fuel Inlet NPT . . . . . . . . . . . . . . 1.4" (6.4 mm)
F. Fuel Outlet NPT . . . . . . . . . . . . 1" (25.4 mm)
G. Coolant Inlet and Outlet NPT . . . 3.8" (9.5 mm)
Model N-H420 Regulator . 400 HP
Parts Description, Installation & Operation
GENERAL The N-H420 two-stage regulator is an LPG liquid
withdrawal high pressure regulator with a heat exchanger
that will vaporize enough fuel for up to 400 HP engines.
WARNING! The N-H420 should be installed and maintained
per these instructions and all applicable federal, state, and
local laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not
considered a positive shut-off valve. An approved
automatic shut-off device is required to be installed. This
will shut off the fuel supply should the engine fail while
unattended. Shut-off devices come in vacuum- or
solenoid-actuated configurations.
OPERATION With the N-H420's improved vaporization
characteristics, liquid propane enters the regulator and
then is vaporized using heat from the engine's coolant.
Tank pressure is reduced to approximately 1.5 psi. As
negative pressure is transmitted from the carburetor to
the regulator, the regulator releases propane vapor to the
carburetor. Some regulators are equipped with a primer
button. Correctly installed regulator should not require
priming. If priming is required, a maximum duration of
only 1 second should be used.
INSTALLATION The N-H420 should be mounted as close
to the carburetor as possible, with the fuel outlet placed in
the lowest position for best flow.
SERVICE The N-H420 should be periodically checked for
leakage. If the unit requires service, we suggest you take
it to a qualified service technician. If not available, we will
furnish a list of repair facilities or provide service
information.
REGULATORS N-H420 VAPORIZER/REGULATOR Information & Dimensions
22
U.L Listed
. Propane liquid withdrawal vaporizing regulator
. For liquid-cooled engines up to 400 HP
. Compact, low-profile design
. Rated to 312 psi maximum inlet pressure
PARTS LISTING
Item Part No. Description Qty.
1* N00-6443 COVER SCREW, 8-32 X 5.8" 8 (RK4)
2 N00-7004 Screen, Secondary 1
3 N-C1-1A Cover Assembly, Secondary 1
4* N-D1-2A DIAPHRAGM ASSEMBLY, SECONDARY, SILICONE 1
5 N00-6443 Cover Screw, 8-32 x 5/8" 8
6 N-P1-2 Pin, Secondary Lever Fulcrum 1
7 N-L1-1 Lever, Secondary 1
8* N-V1-1A VALVE, SECONDARY 1
9 N-S3-2 Spring, Secondary (Blue)** 1
10 N-S3-3 Spring, Secondary (Orange)** 1
11 N-C1-2 Cover, Primary Diaphragm 1
12 N-S3-4 Spring, Primary Regulator 2
13* N-D1-3A DIAPHRAGM ASSEMBLY, PRIMARY 1
14 N-B1-1A Body Assembly 1
15 N00-6104 Plug, 1.8" Pipe 1
16 N-P1-3 Pin, Primary Valve Operating 1
17* N-G1-1 GASKET, GAS & WATER CHAMBER 1
18 N-C1-3 Cover, Gas & Water Chamber 1
19* N00-6400 COVER SCREW, 10-24 X 5.8" 12 (RK2)
20 N00-6402 Mounting Screw, 1.4"-20 x 5/8" 4
21* N-V1-2A VALVE, PRIMARY REGULATOR 1
22 N-S3-5 Spring, Valve Closing 1
23* N-O1-1 O-RING, LP-GAS INLET 1
24 N-P3-2 Plug, LP-Gas Inlet 1
* Indicates Repair Kit Components
** Two outlet fuel flow initiation pressures are available. Orange secondary spring (N-S3-3) requires
approximately negative 0.5 inches of water pressure to initiate fuel flow. Blue secondary spring
(N-S3-2) requires approximately negative 1.5 inches of water pressure.
REPAIR KIT: (Components shown in blue)
N-RKH420SA Repair Kit with Silicone Diaphragm
ORDERING INFO
Part No. Description
N-H420-SA N-H420 Regulator, Blue Spring with
Silicone Diaphragm (UL Listed)
N-H420-OSA N-H420 Regulator, Orange Spring with
Silicone Diaphragm (UL Listed)
Parts Listing N-H420 VAPORIZER/REGULATOR REGULATORS

Note: While only certain parts are available for individual purchase, all parts are listed for reference purposes.
Note: Parts in blue are
components of Repair Kit
(N-RKH420SA).
REGULATOR SPECIFICATIONS
A. Overall Width . . . . . . . . . . . . . . 61.2" (165.1 mm)
B. Overall Length . . . . . . . . . . . . 61.10" (154.9 mm)
C. Body Width. . . . . . . . . . . . . . . 57.10" (144.8 mm)
D. Overall Depth . . . . . . . . . . . . . 53.5" (142.2 mm)
E. Mounting Holes Center to Center222.25" (73.2 mm)
F. Mounting Screws (4). . . . . . . . . . . . . . 1.4-20 x 5.8"
G. Fuel Outlet NPT. . . . . . . . . . . . . . 1" (25.4 mm)
H. Fuel Inlet NPT. . . . . . . . . . . . . . . . 1.4" (6.4 mm)
J. Coolant Inlet and Outlet NPT . . . . . 3.8" (9.5 mm)
K. Hose Barb . . . . . . . . . . . . . . . . . . . 3.8" (9.5 mm)
Model N-H420 Turbo
Parts Description, Installation & Operation
GENERAL The N-H420 Turbo two-stage regulator is an LPG liquid
withdrawal high-pressure regulator with an integrated heat
exchanger vaporizer.
WARNING! The N-H420 Turbo should be installed and
maintained per these instructions and all applicable federal,
state, and local laws and codes.
Special Note in regards to NFPA Pamphlet 58: For indoor
applications by NFPA definition, a regulator is not considered a
positive shut-off valve. An approved automatic shut-off device is
required to be installed. This will shut off the fuel supply should