Manufacturing Cost Estimation for
Class 2B/3 CNG Systems
£EPA
United States
Environmental Protection
Agency
-------
Manufacturing Cost Estimation for
Class 2B/3 CNG Systems
Assessment and Standards Division
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
Prepared for EPA by
FEV North America, Inc.
EPA Contract No. EP-C-12-014 WA2-03
NOTICE
This technical report does not necessarily represent final EPA decisions or
positions. It is intended to present technical analysis of issues using data
that are currently available. The purpose in the release of such reports is to
facilitate the exchange of technical information and to inform the public of
technical developments.
&EPA
United States
Environmental Protection
Agency
EPA-420-D-15-004
June 2015
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Table of Contents
Executive Summary
1. Introduction and Program Objectives
1.1. Objective
1.2. Vehicle Selection
1.3. Background
2. System Overview & Cost Structure
2.1. System Design
2.2. Hardware
2.3. BOM Creation
2.4. Costing Methodology
3. Storage Subsystem
3.1. Tank Cover Sub-Subsystem
3.2. Cradle Sub-Subsystem
3.3. Tank Sub-Subsystem
4. Safety Devices Subsystem
4.1. High Pressure Lock-Off Valve Sub-Subsystem
4.2. Safety Relief Valve Sub-Subsystem
4.3. Excess Flow Valve Sub-Subsystem
4.4. Purge Sub-Subsystem
5. High Pressure Circuit Subsystem
5.1. Filler (Refueling) Sub-Subsystem
5.2. Distribution, High Pressure Sub-Subsystem
5.3. Filter Sub-Subsystem
5.4. Pressure Regulator Sub-Subsystem
6. Low Pressure Circuit Subsystem
6.1. Distribution, Low Pressure Sub-Subsystem
6.2. Fuel Rails Sub-Subsystem
6.3. Fuel Injector Sub-Subsystem
7. Controls Subsystem
7.1. Control Module Sub-Subsystem
7.2. Wire Harnesses Sub-Subsystem
8. Cost Summary and Conclusion
9. Appendix A
Analysis Report BAV-P310324-03
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Analysis Report BAV-P310324-03
June 26, 2015
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List of Figures
Figure 1- Chevrolet Silverado 2500 CNG 8
Figure 2- Compressed Natural Gas (CNG) System 12
Figure 3- CNG System Hardware 14
Figure 4- Storage Subsystem 18
Figure 5- Tank Cover Sub-Subsystem - Assembled 19
Figure 6- Tank Cover Sub-Subsystem - Components 20
Figure 7- Cradle Sub-Subsystem - Components 21
Figure 8- CNG Tank 23
Figure 9- CNG Tank Label 24
Figure 10- Silverado CNG Tank Section # 1 24
Figure 11 - Silverado CNG Tank Section #2 25
Figure 12- Step 1: Seamless Aluminum Tube Cut to Length 26
Figure 13- Step 3: Preheating of Blank Prior to Spin Form 26
Figure 14- Step 4: Blank Chucked in Spin Form Machine 27
Figure 15- Step 4-1: Spin Forming 27
Figure 16- Step 4-2: Spin Forming 28
Figure 17- Step 5: Heat Treatment (Stress Relief) 28
Figure 18- Step 8: Carbon Fiber Wrapping 29
Figure 19- Step 8: Carbon Fiber Wrapping (Continued) 29
Figure 20- High Pressure Lock-Off Sub-Subsystem -Assembled 31
Figure 21- High Pressure Lock-Off Sub-Subsystem - Components 31
Figure 22- High Pressure Lock-Off- Exploded View 32
Figure 23- Safety Relief Valve - Assembled 33
Figure 24- Safety Relief Valve - Components 34
Figure 25- Safety Relief Valve - Exploded View 34
Figure 26- Excess Flow Valve - Assembled 36
Figure 27- Excess Flow Valve - Exploded 36
Figure 28- Purge Sub-Subsystem - Components. 38
Figure 29- Filler Sub-Subsystem - Components 39
Figure 30- Fill Port - Exploded View 39
Figure 31- Distribution, High Pressure Sub-Subsystem 41
Figure 32- Filter Sub-Subsystem - Components 42
Figure 33- CNG Filter - Exploded View 42
Figure 34- Pressure Regulator Sub-Subsystem - Components 44
Figure 35- Pressure Regulator - Exploded View 44
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Analysis Report BAV-P310324-03
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Figure 36- Distribution, Low Pressure Sub-Subsystem - Components 46
Figure 37- Fuel Rails Sub-Subsystem - Components 47
Figure 38- Injector Nozzle - Components 47
Figure 39- Fuel Injector Sub-Subsystem - Components 48
Figure 40- CNG Fuel Injector - Sectioned 49
Figure 41- Control Module Sub-Subsystem - Components 50
Figure 42- CNG ECU - Exploded View 50
Figure 43- CNG ECU Board with Circuit ID numbers - Top 51
Figure 44- CNG ECU Board with Circuit ID numbers - Bottom 52
Figure 45- Wire Harness Sub-Subsystem 53
Figure 46- CNG Subsystems 55
Figure 47- Manufacturing and Mark-up Cost 55
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Analysis Report BAV-P310324-03
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List of Tables
Table 1- U.S. Product Supplied of Finished Motor Gasoline 9
Table 2- U.S. Alternative Fueling Stations by Fuel Type 10
Table 3- BOM Compressed Natural Gas (CNG) System 16
Table 4- BOM Tank Cover Sub-Subsystem 20
Table 5- BOM Cradle Sub-Subsystem 22
Table 6- BOM CNG Tank Sub-Subsystem 30
Table 7- BOM High Pressure Lock-Off Valve Sub-Subsystem 32
Table 8- BOM Safety Relief Valve Sub-Subsystem 35
^^1
Table 9- BOM Excess Flow Valve Sub-Subsystem 37
Table 10-BOM Purge Sub-Subsystem 38
Table 11- BOM Filler (Refueling) Sub-Subsystem 40
Table 12- BOM Distribution, High Pressure Sub-Subsystem 41
Table 13- BOM Filter Sub-Subsystem 43
Table 14- BOM Pressure Regulator Sub-Subsystem 45
Table 15- BOM Distribution, Low Pressure Sub-Subsystem 46
Table 16- BOM Fuel Rails Sub-Subsystem 48
Table 17- BOM Fuel Injectors Sub-Subsystem 49
Table 18- BOM Control Module Sub-Subsystem 52
Table 19- BOM Wire Harnesses Sub-Subsystem 53
Table 20 - CNG Subsystem Cost Summary Overview 54
Table 21 - Complete Cost Summary (CMAT) - CNG System 57
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Analysis Report BAV-P310324-03
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Executive Summary
The United States Environmental Protection Agency (EPA) contracted with FEV North
America, Inc., to determine incremental direct manufacturing costs for a complete CNG
fuel system. The system selected to represent the light-duty vehicle segment was a
2013 Chevrolet Silverado equipped with General Motors Bi-Fuel option. The Silverado
was purchased by FEV and all CNG related components were identified. The vehicle
was then completely disassembled. Names, photos and weights were assigned to all
CNG related components and compiled in a Bill of Materials (BOM). All CNG system
components were reviewed in detail and cost estimated using FEV's standard costing
process. All costs were developed using a volume assumption of 450,000 units per
year. This cost analysis is inclusive of all associated assembly cost from component to
vehicle. Calculations were performed to determine equipment sizing, cycle times and
material usage requirements. FEV utilized its extensive database of rates for
equipment, labor, material, end item scrap, selling, general and administrative (SG&A),
profit, and engineering, design and testing (ED&T) to develop costs representative of
what an OEM would incur for such a system in high volume automotive manufacturing.
Cost for the five (5) subsystems are as follows:
1. Storage-$1,360
2. Safety Devices-$151
3. High Pressure Circuit-$184
4. Low Pressure Circuit-$278
5. Controls-$303
Total System cost = $2,276
Sixty (60) percent of the system cost can be attributed to CNG storage. Gasoline's 17x
energy density factor over natural gas at atmospheric conditions creates a storage
challenge for CNG. High pressure storage (3600psi) is required to minimize this energy
density differential. Pressure, weight, and safety requirements all contribute to CNG
tank costs. The one-piece, seamless, carbon fiber reinforced tank undergoes a twelve
(12) step manufacturing process before completion. In light of carbon fiber processing
improvements like pre-preg fibers, the process of wrapping is a time consuming cost
driver. Make up 44% of the tank cost. The wrapping process and material cost of
carbon fiber.
The System is comprised of: high pressure lock-off, pressure relief device, and excess
flow valve.
High Pressure Circuit includes; refueling filler, fuel lines, filter and pressure regulator.
Low Pressure Circuit includes; fuel lines, fuel rails and CNG injectors.
Controls include; ECU, intake air temperature module, fuel pump module, and wiring.
General Motors Bi-Fuel System was designed as an add-on to an existing gasoline
engine. As an add-on, the CNG system has its own ECU requiring Intake Air
Temperature and Fuel Pump control modules. A dedicated CNG system would
eliminate these components, reducing overall vehicle cost.
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Analysis Report BAV-P310324-03
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1. Introduction and Program Objectives
1.1. Objective
The objective of this study is to develop cost for a complete light-duty truck CNG
system, manufactured at high production volume (450,000 units per year).
1.2. Vehicle Selection
A 2013 Silverado 2500 4WD LT Extended CAB truck with bi-fuel option was selected as
a representative light-duty passenger vehicle CNG system. The truck was equipped
with a 6.0L Vortec engine, GM designation LC8. The CNG system is modular and was
designed as an add-on option to GM's existing product.
Figure 1- Chevrolet Silverado 2500 CNG
(Source: FEV, Inc. photos)
1.3. Background
For the same energy output, combustion of CNG produces 29% less carbon dioxide
than combustion of oil base fuels (i.e., gasoline). 'In most applications, using natural
gas produces less of the following substances than oil or coal: carbon dioxide (C02),
the primary greenhouse gas; sulfur dioxide, which is the primary precursor of acid rain;
nitrogen oxides, which is the primary precursor of smog; and particulate matter, which
can affect health and visibility.'
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Analysis Report BAV-P310324-03
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http://www.aga.org/our-
Issues/issuesummaries/Pages/EnvironmentalBenefitsofNaturalGas.aspx
In 2013 the US consumed 3.2 billion barrels of gasoline as shown in Table 1. In
addition to fuel reduction technologies like turbo-downsizing and lightweighting, CNG
offers another option to reducing petroleum-based fuel consumption.
U.S. Product Supplied of Finished Motor Gasoline
Thousand Barrels
4,000,000
3,000,000
2,000,000
1,000,000
1950 1960 1970 1980 1990 2000 2010
— U.S. Product Supplied of Finished Motor Gasoline
Source: U.S. Energy Information Administration
Table 1- U.S. Product Supplied of Finished Motor Gasoline
http://www.eia. gov/tools/fags/fag.cfm?id=23&t=10
'CNG conversions can provide stability against fluctuating fuel prices as well as lower
vehicle operating costs for fleet administrators. CNG sells for an average of $2.10 per
Gasoline Gallon Equivalent (GGE), and is as low as $1 in some parts of the country,
representing a significant savings over unleaded regular fuel. The national price range
for unleaded regular fuel is $2.25 - $3.50 per gallon'.
http://corporate.ford.com/news-center/press-releases-detail/first-cng-capable-2014-ford-
f-150-rolls-off-the-line-in-kansas
Storing enough natural gas in a motor vehicle to provide a sufficient range is a
challenge with CNG. To improve upon its lower energy density, natural gas is stored at
3600 psi. Even at this pressure fuel tank size is significantly larger. For example the
Silverado CNG tank is rated at 17 GGE gallons however, the actual internal tank
volume as measured after sectioning by FEV is approximately 55 gallons. GGE is
based on an equal measure of energy making it possible to compare cost per unit of
alternate fuels, GGE in terms of CNG Gas (Volume/Pressure/Temp) = 1 Gallon of Gas
(Temp, Pressure=atm). For example 1 GGE of CNG and 1 gallon of gasoline are
equivalent.
At this time, the primary drawbacks of CNG are the underdeveloped vehicle refueling
infrastructure and the fuel storage requirements. As of 2013 there were approximately
1,260 CNG refueling stations in the country.
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Analysis Report BAV-P310324-03
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U.S. Alternative Fueling Stations by Fuel Type
30,000
Print Download
• Elect- ;'
Propane
• Methanol (M85)
• LNC
• Hydrogen
• Biodiesel**
• CNG
• ESS
1992 1995 1998 2001 2004 2007 2010 2013
Table 2- U.S. Alternative Fueling Stations by Fuel Type
http://www.afdc.energy.gov/data/10332
Implementing a high pressure CNG system in a passenger vehicle requires safety
provisions not needed with conventional gasoline. Directly mounted to the CNG tank
are two (2) safety devices. The first is an electronic flow lock preventing CNG from
leaving the tank unless permitted by the ECU. The second is a pressure relief valve
with back-up burst disc to prevent overpressure in the CNG system. A manual isolation
valve is located after the tank for service and an additional electronic flow lock is located
in the pressure regulator. A flow fuse is used to cut-off flow in the event the system is
ruptured and the intended gas flow rate is exceeded.
Higher combustion temperatures and corrosive properties of natural gas require
hardened exhaust valves and intake/exhaust valve seats.
http://www.qmfleet.com/vehicle-overviews/fuel-efficiency/bi-fuel.html
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Analysis Report BAV-P310324-03
June 26, 2015
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2. System Overview & Cost Structure
2.1. System Design
Figure 2 is a schematic representation of the CNG system generated as an aid to
understand the components and their function. The system was broken into five (5)
subsystems and color coded at the bottom of the figure. The CNG tank manages fuel
pressures up to 3600 psi when full. Directly mounted to the CNG tank are the Safety
Relief Valve and High Pressure Lock-off (HPL) solenoid.
Connecting to the underbody purge line is the safety relief assembly. A spring piston
with plastic face seal opens when the tank pressure exceeds the design limit. Over
temperature conditions exceeding the melting point of the plastic face seal will also
open this valve. The pressure burst disc is a secondary safety device protecting the
tank from over pressure.
The opposite end of the tank mounts the HPL solenoid. This valve requires activation
before any gas is permitted to exit the tank. Integrated into this assembly is a manual
purge valve, providing a means to vent the system to the atmosphere, and a
temperature transmitter extending into the tank cavity.
Following the HPL solenoid is the excess flow valve. This device protects the system
from a downstream rupture. If the gas flow exceeds the limit of this valve it closes.
When pressure across the valve equalizes the valve automatically resets.
The fill circuit consists of a quick release with integrated check valve for ensuring one-
way flow. The quick release serves as the connection point for refueling. A secondary
check valve located after the quick release again ensures one-way flow. The fill circuit
continues to the tank with reverse flow through both the excess flow valve and HPL
solenoid.
Continuing from the excess flow valve, fuel travels through a manual ball (service) valve
to the filter before entering the pressure regulator. Integrated into the pressure
regulator is a normally closed solenoid valve in addition to pressure and temperature
transmitters. The solenoid valve provides another level of security from unintended fuel
flow. Heat absorption caused by the expansion of gas requires a heating circuit which
ties into the engine cooling system. The pressure regulator reduces pressure to 100
psig.
Following the pressure regulator, fuel is routed to the fuel rails supplying eight (8)
individual CNG injectors. The injectors terminate via hose to port mounted nozzles in
the intake manifold.
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Analysis Report BAV-P310324-03
June 26, 2015
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HIGH: PRESSURE LOCK-OFF
SOLE I*OID ASSEMBLY
SAFETY RE LIEF ASSEMBLY
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Low Pressure Circuit Subsystem
Controls Subsystem
ECU
FUEL
PUMP
MODULE
IAT
MODULE
WIRING
Figure 2- Compressed Natural Gas (CNG) System
(Source: FEV, Inc. photos)
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Analysis Report BAV-P310324-03
June 26, 2015
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2.2. Hardware
Primary CNG hardware is shown in Figure 3 in order as follows:
Type 3 CNG Tank
• Manufacturer: Structural Composites Industries; P/N:319875
• Construction: Seamless Aluminum, Carbon Fiber reinforced
High Pressure Lock-Off (HPL)
• Manufacturer: GFI Control Systems; P/N:PT13F0172
• Construction: Billet Aluminum
• Features: Temperature Measurement, Manual Purge Valve
Pressure Relief Device (PRO)
• Manufacturer: GFI Control Systems; P/NPRD-120BD
• Construction: Billet Aluminum
Flow Fuse
• Manufacturer: HOKE; P/N:HVX316
• Construction: 316 stainless steel, brass, Monel®, Hastelloy® C-276
Distribution Lines
• Seamless Stainless Steel & Stainless Steel Jacketed PTFE
Filter
• Manufacturer: Parker; P/N:FFC-112 SAE-10
• Construction: Billet Aluminum, Coalescing Media Filter
High Pressure Regulator (HPR)
• Manufacturer: GFI Control Systems; P/N:P214-980
• Construction: Forged Aluminum
• Features: High Pressure Shut-Off Solenoid, High Pressure Transducer, MAP
referencing
Fuel Rail
• Billet Aluminum
Fuel Injector
• Manufacturer: AC Delco; P/N:22991067
Engine Control Unit (ECU)
• Manufacturer: Fly SF; P/N:028705/9-V
Control Modules - Intake Air Temperature (IAT), Fuel Pump
• Manufacturer: IMPCO Automotive; P/N: MD-53497-001, MD-54548-001
Wiring
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Analysis Report BAV-P310324-03
June 26, 2015
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CNG System Hardware
CNG Tank
HPL
PRO
Flow Fuse
HPR
ECU
Distribution Lines
Filter
Fuel Rail
Fuel Injector
- L
f r
<— ^J
Control Modules
Wiring
Figure 3- CNG System Hardware
(Source: FEV, Inc. photos)
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Analysis Report BAV-P310324-03
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2.3. BOM Creation
The CNG system was disassembled starting with the tank, following the flow path, and
ending with the fuel injectors. Assemblies were removed from the vehicle in groups that
were thought to represent actual assembly. After removal from the vehicle
assembles/components were photographed, weighed and tagged.
The first step in disassembly of the CNG system was to purge all CNG from the tank.
This was done by releasing the manual purge valve and deactivating the solenoid lock-
off valve. Next, the tank, cradle and related hardware were removed from the bed of
the truck. Subsequently in conjunction with another study the entire truck was
disassembled and all CNG related system components were removed, named,
photographed, weighted and logged into a Bill of Material (BOM).
The CNG system was categorized into five (5) main Sub-Systems: Storage, Safety
Devices, High Pressure Circuit, Low Pressure Circuit, and Controls. The storage
subsystem includes the tank cover, tank cradle, and tank. The Safety Devices
subsystem includes the high pressure lock-off, high pressure relief device, and excess
flow valve. The high pressure circuit includes all high pressure fuel lines as well as fuel
filter and pressure regulator. The low pressure circuit includes all low pressure fuel
lines as well as cooling lines associated with the pressure regulator heating circuit. Also
included in this subsystem are the fuel rail and fuel injectors. The wiring harness,
control modules and ECU are included in the Controls Subsystem.
The BOM structure shown in Table 3 details the subsystems and Sub-Subsystems
which can be identified in the system schematic as segregated color shaded areas.
The 'Purge' and 'Distribution, Low Pressure' Sub-Subsystems are shaded darker to
highlight included plumbing.
Every Sub-Subsystem, assembly, or component listed in the BOM features: mass,
photo link, cost, and quote link.
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Analysis Report BAV-P310324-03
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Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 01 01
20 01 02
20 01 03
20 02 00
20 02 01
20 02 02
20 02 03
20 02 04
20 03 00
20 03 01
20 03 02
20 03 03
20 03 04
20 04 00
20 04 01
20 04 02
20 04 03
20 05 00
20 05 01
20 05 02
Part Name/Description
| Product Structure
CO §- o
<§ §- co •
! $ §- 51
m rt-^"° ->-Niw-ii.cna)--jc»cQ<_)
= 3> w i-
3 ff <5
3 CD.
Compressed Natural Gas System
Storage Subsystem
Tank Cover Sub-Subsystem
Cradle Sub-Subsystem
Tank Sub-Subsystem
Safety Devices Subsystem
High Pressure Lock-Off Valve (HPLV) Sub-Subsystem
Safety Relief Valve Sub-Subsystem
Excess Flow Valve Sub-Subsystem
Purge Sub-Subsystem
High Pressure Circuit Subsystem
Filler (Refueling) Sub-Subsystem
Distribution, High Pressure Sub-Subsystem
Filter Sub-Subsystem
Pressure Regulator Sub-Subsystem
Low Pressure Circuit Subsystem
Distribution, Low Pressure Sub-Subsystem
Fuel Rails Sub-Subsystem
Fuel Injectors Sub-Subsystem
Controls Subsystem
Control Module Sub-Subsystem
Wire Harnesses Sub-Subsystem
QTY
O
c
01
D
=±
•?
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
8
1
1
1
Attribute
Data
Mass
!i
~i-
m= $ s
x Q)
X tfi
j2 tn
^
239.334
209.889
33.650
78.280
97.959
6.603
3.676
1.004
0.463
1.460
7.732
0.637
2.387
0.613
4.095
8.622
4.621
3.825
0.176
6.488
3.688
2.800
Table 3- BOM Compressed Natural Gas (CNG) System
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Analysis Report BAV-P310324-03
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2.4. Costing Methodology
This cost analysis is a full system complete evaluation inclusive off all hardware
associated with the CNG system. Included in the cost is component assembly to the
vehicle. The CNG system as analyzed is a low-volume design, often utilizing off-the-
shelf hardware. On specific components, where a high volume manufacturing choice
was clear, alternative manufacturing assumptions were made. For example, the safety
relief protection collar was manufactured from billet however it was quoted as a die
casting. Such assumptions are noted in detail throughout the body of this report. The
volume assumption for cost estimation was 450,000 vehicles per year.
Costs were developed for all critical components by detailing each operation in a
Manufacturing Assumptions Quote Sheet (MAQS). Process calculators were used to
determine equipment size and corresponding rate ($/hr), cycle time (seconds) and
material usage (kg). For example, the Pressure Regulator Cap was identified as an
aluminum die casting. The number of slide pulls, cavities, part width, part height,
average wall thickness, parting line area, cavity surface area, and max wall thickness
were all used to determine the die-casting machine size, cycle time and material usage.
This information was then transferred to the MAQS where rates are pulled in for
material, labor, manufacturing overhead/burden, end item scrap, SG&A, profit, and
ED&T. Cost contributions are then calculated for these core cost elements. Similar
process calculators are used for subsequent processing such as machining, where all
machine features are measured, speed and feed rates assigned based on the
respective material, and feed times calculated. In addition pallet changes, tool changes,
rapid times, as well as estimated work pieces per fixture are used to estimate the total
cycle time. Finally all processes are summed, end item packaging estimated, and total
cost calculated. Cost contributions for the core cost elements are then linked to the
Cost Model Analysis Template (CMAT). The CMAT incorporates cost data from various
Sub-Subsystems into one summary sheet. Process costs were estimated as follows:
1. Detailed assessment of manufacturing processes used to create the component
2. Populate appropriate process calculator, identifying equipment size, cycle time,
and material usage
3. Transfer data from step 2 into quotation sheet and assign labor resources
4. Repeat for all manufacturing processes required
5. Repeat for all components in Sub-Subsystem
6. Evaluate Sub-Subsystem assembly requirements including: number of stations,
level of automation, burden rate, number of operators, and cycle time
7. Evaluate vehicle assembly requirements including: number of stations, level of
automation, burden rate, number of operators, and cycle time
8. Assess packaging needs and estimate packaging costs
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Analysis Report BAV-P310324-03
June 26, 2015
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3. Storage Subsystem
The storage subsystem includes all hardware associated with the CNG tank.
subdivided into the following Sub-Subsystems:
• Tank Cover Sub-Subsystem
• Cradle Sub-Subsystem
• Tank Sub-Subsystem
It is
Figure 4- Storage Subsystem
(Source: FEV, Inc. photos)
3.1. Tank Cover Sub-Subsystem
Figure 5 shows the tank cover as assembled in the bed of the Silverado. The cover
fastens to the cradle and cover mount bracket.
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Analysis Report BAV-P310324-03
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Figure 5- Tank Cover Sub-Subsystem - Assembled
(Source: FEV, Inc. photos)
The Tank Cover Sub-Subsystem includes the fabricated diamond plate aluminum tank
cover with access door, steel bracket, and associated fasteners as shown in Figure 6.
For high volume production the Tank Cover was estimated as multiple stampings
assembled as a weldment. The cover mount was heavy gauge material and also
processed as a multiple stamping weldment.
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Analysis Report BAV-P310324-03
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Figure 6- Tank Cover Sub-Subsystem - Components
(Source: FEV, Inc. photos)
The bill of materials for Tank Cover Sub-Subsystem
Subsystem mass is 33.7 kg and the cost is $94.
is shown in Table 4. Sub-
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 01 01
20 01 01
20 01 01
20 01 01
20 01 01
20 01 01
20 01 01
Part Name/Description
Sub-Subsystem
Subsystem
System
Product Structure
o
o
T3 -^NJCO-NCncn^JOOCOi-i
sr
i
Compressed Natural Gas System
Storage Subsystem
Tank Cover Sub-Subsystem
Tank Cover
Bolt, Tank Cover
Cover Mount, Cradle, Tank
Bolt, Long, Cover Mount, Cradle, Tank
Bolt, Short, Cover Mount, Cradle, Tank
Nut, Cover Mount, Cradle, Tank
QTY
O
c
fl>
3.
Z¥
*<
1
1
1
9
1
4
4
8
Attribute Cost
Data Analysis
Mass
J!
m=g! s
x 8!
-S- w
*<
33.650
21 .508
0.189
1 1 .425
0.198
0.157
0.173
Unit Cost
$94
Table 4- BOM Tank Cover Sub-Subsystem
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Analysis Report BAV-P310324-03
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3.2. Cradle Sub-Subsystem
The Cradle bolts into the box of the truck and serves as a mounting structure for the
tank. The tank is secured to the cradle with two (2) rubber lined straps fastened with
bolts. Cradle Sub-Subsystem components are shown in Figure 7.
Figure 7- Cradle Sub-Subsystem - Components
(Source: FEV, Inc. photos)
The Cradle Sub-Subsystem is a weldment of thirteen (13) individual stampings. Three
(3) sprung retaining mechanisms were used to attach the cradle to the back of the truck
box. These retainers were estimated by assuming a clipnut for high volume production.
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Analysis Report BAV-P310324-03
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The bill of materials for the Cradle Sub-Subsystem is shown in Table 5. Sub-
Subsystem mass is 78.3 kg and the cost is $193.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 01 01
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
20 01 02
Part Name/Description
Sub-Subsystem
Subsystem
System
Product Structure
o
51
T3 -^K>CO^O1O)^JOO(DO
1
(D_
Compressed Natural Gas System
Storage Subsystem
Tank Cover Sub-Subsystem
Cradle Sub-Subsystem
Bolt, Cradle, CNG Tank, Bottom
Washer, Cradle, CNG Tank, Bottom
Retainer Assembly, Cradle, CNG Tank, Back
Collar, Cradle, CNG Tank, Back
Bolt, Cradle, CNG Tank, Back
Washer, Cradle, CNG Tank, Back
Nut, Cradle, CNG Tank, Bottom
Bolt, Strap, CNG Tank
Washer, Strap, CNG Tank
Straps, CNG Tank
Bolt, Welded Strap, CNG Tank
Cradle, CNG Tank
QTY
O
c
ffl
3
•<"
1
1
1
4
4
3
3
3
1
4
4
18
2
2
1
Attribute Data
Mass
'c
»*
*fi
<°:% z.
X ffl
x <1>
-3. 0)
•<"
239.334
209.889
33.650
78.280
0.421
0.085
0.517
0.090
0.096
0.012
0.087
0.325
0.167
4.221
0.150
72.109
Photo
Catalog
Picture
Reference
Numbers
2001
20 01 01
20 01 02
CIMG0020
CIMG0021
CIMG0029
CIMG0030
CIMG0032
CIMG0033
CIMG0035
CIMG0101
CIMG0102
CIMG0103
CIMG0110
CIMG0112
Cost
Unit Cost
$193
Table 5- BOM Cradle Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 23
3.3. Tank Sub-Subsystem
The CNG tank used on Silverado is a type 3 container made by Structural Composite
Industries, a Worthington Cylinders Company as shown in Figure 8. CNG cylinders are
available in 4 types, with type 1 being the heaviest and least expensive to type 4 being
the lightest and most expensive. Type 3 tanks have a seamless and gas tight metal
liner reinforced by composite wrap around the entire tank. The tank has a 15 year
service life after which the tank must be replaced. Type 3 CNG tanks are pressure
rated for 3600psi and are tested at 5500psi. Worthington manufactures all their
cylinders to aviation standards, with a burst safety factor of at least 3.0 and with design
verification impact testing about the full cylinder periphery.
98kg/216lbs
Figure 8- CNG Tank
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 24
USE .via K
3600 PSiG/70'F
ALT 1026
P/N 319875
37-13 <••
•40T
TYPE
Figure 9- CNG Tank Label
(Source: FEV, Inc. photos)
Figure 9 show the label Figure 10 show the Silverado CNG Tank sectioned lengthwise.
Composite wrap thickness thins around the radius and thickens around the ends of the
tank.
Figure 10- Silverado CNG Tank Section # 1
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 25
Figure 11- Silverado CNG Tank Section # 2
(Source: FEV, Inc. photos)
Steps and images for CNG tank manufacturing are outlined below:
Step 1: Saw seamless aluminum tube
Step 2: Ultrasonic scanning of tube for imperfections
Step 3: Preheat tube to initiate forming
Step 4: Spin forming
Step 5: Stress relief
Step 6: Machine neck threads
Step 7: Apply corrosion protectant
Step 8: Composite carbon fiber wrap
Step 9: Resin coating
Step 10: Oven cure resin
Step 11: Hydrostatic leak test
Step 12: Random sample burst test
http://www.youtube.com/watch?v=XxRiyCGtKgo
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 26
Figure 12- Step 1: Seamless Aluminum Tube Cut to Length
http://www.youtube.com/watch?v=-NDvGYfwTxs
Figure 13- Step 3: Preheating of Blank Prior to Spin Form
http://www.youtube.com/watch?v=XxRivCGtKgo
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 27
Figure 14- Step 4: Blank Chucked in Spin Form Machine
http://www.youtube.com/watch?v=-NDvGYfwTxs
Figure 15- Step 4-1: Spin Forming
http://www.youtube.com/watch?v=-NDvGYfwTxs
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 28
Figure 16- Step 4-2: Spin Forming
http://www.youtube.com/watch?v=-NDvGYfwTxs
Figure 17- Step 5: Heat Treatment (Stress Relief)
http://www.youtube.com/watch?v=XxRivCGtKgo
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 29
Figure 18- Step 8: Carbon Fiber Wrapping
http://www.youtube.com/watch?v=XxRivCGtKgo
Figure 19- Step 8: Carbon Fiber Wrapping (Continued)
http://www.fleetsandfuels.com/fuels/cng/2012/11/cleanng-readies-all-new-cng-
tank/attachment/cleanng magmacel-1111
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 30
The bill of materials for the CNG Tank is shown in Table 6. Tank mass is 98 kg and the
cost is $1,073.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 01 01
20 01 02
20 01 03
20 01 03
Part Name/Description
Product Structure
w & o
^ & W '
t'iffl'-.OW^CIia^.a.W-
3 |f]:l^K'"^tn0)^00
-3. 0)
239.334
209.889
33.650
78.280
97.959
97.959
Photo
Catalog
Picture
Reference
Numbers
2001
20 01 01
20 01 02
20 01 03
CIMG0098
Cost
Unit Cost
$1,073
Table 6- BOM CNG Tank Sub-Subsystem
4. Safety Devices Subsystem
4.1. High Pressure Lock-Off Valve Sub-Subsystem
Figure 20 shows the High Pressure Lock-Off Valve directly connected to the driver's
side tank end. All components included in this Sub-Subsystem are shown in Figure 21.
The protective cover and collar were assumed die casting and sand cast respectively
for high volume production. The High Pressure Lock-off Valve body was machined from
billet aluminum. All components making up the HPLV were identified in the cost file with
the BOM part number and the ID number assigned in Figure 22.
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 31
Figure 20- High Pressure Lock-Off Sub-Subsystem - Assembled
(Source: FEV, Inc. photos)
Figure 21- High Pressure Lock-Off Sub-Subsystem - Components
(Source: FEV, Inc. photos)
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Analysis Report BAV-P310324-03
June 26, 2015
Page 32
Figure 22- High Pressure Lock-Off- Exploded View
(Source: FEV, Inc. photos)
The bill of materials for the High Pressure Lock-Off Valve Sub-Subsystem is shown in
Table 7. Mass is 3.7 kg and the cost is $55.
Part Numbering
CO
co §•
4? & w
a -S &
0) (/)(/)
3 | -5
3 ff
20 00 00
20 01 00
20 02 00
20 02 01
20 02 01
20 02 01
20 02 01
20 02 01
20 02 01
20 02 01
20 02 01
20 02 01
Part Name/Description
Product Structure
co
w D- o
4? §• w •
5T "w §" -§ ^ M oo 0,0, j 00 CO ^
3 2J" "5 r-
3 f ?
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Lock-Off Valve (HPLV) Sub-Subsystem
Cover HLPV
Bolt, Cover HLPV
Collar, Protection, HPLV
Bolt, Collar, Protection, HLPV
P-Port Plug
I/02 Port
Line adapter, HLPV
HLPV
QTY
O
Q)
I
1
1
1
1
4
2
2
1
1
1
1
Attribute Data
Mass
!«*
^i^
,j^ ir
CQ C/) ^
O (/)
239.334
209.889
6.603
3.676
0.469
0.007
2.256
0.036
0.015
0.025
0.046
0.822
Photo
Catalog
Picture
Reference
Numbers
2001
20 02 01
CIMG0001
CIMG0002
CIMG0034
CIMG0036
CIMG0054
CIMG0055
CIMG0059
CIMG0062
Cost
Unit Cost
$55
Table 7- BOM High Pressure Lock-Off Valve Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 33
4.2. Safety Relief Valve Sub-Subsystem
Figure 23 shows the Safety Relief Valve assembled to the passenger side tank end.
Separate outlets are used for both the pressure/temperature relief valve and the burst
disc. Both outlets join the manual purge valve outlet before continuing to the underbody
atmospheric vent.
Figure 23- Safety Relief Valve - Assembled
(Source: FEV, Inc. photos)
Figure 24 identifies all components included in the Safety Relief Valve Sub-Subsystem.
Unlike the protective collars of the HPLV, cross sectional thickness of the safety relief
valve protective collars were able to be die cast. The protective cover was estimated as
die cast as well. With exception to seals, washers, and fasteners, core components are
all made from stainless steel and aluminum.
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 34
Figure 24- Safety Relief Valve - Components
(Source: FEV, Inc. photos)
Figure 25 shows the components with the pressure relief device. In the left of the
picture is the over pressure relief valve assembly with belleville spring set and heat
sensitive seat. The second component in from the right is the rupture disc.
r \
U • • Y
\ \ \
Figure 25- Safety Relief Valve - Exploded View
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 35
The bill of materials for the Safety Relief Valve Sub-Subsystem is shown in Table 8.
Mass is 1.0 kg and the cost is $26.
Part Numbering
CO
C
CO O"
{P §- co
K. •< §-
1 1 1
3
20 00 00
20 01 00
20 02 00
20 02 01
20 02 02
20 02 02
20 02 02
20 02 02
20 02 02
20 02 02
20 02 02
Part Name/Description
Product Structure
c
CO D- 0
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 36
Figure 26- Excess Flow Valve - Assembled
(Source: FEV, Inc. photos)
Figure 27 shows the internal components comprising the Excess Flow Valve. All
working components of this assembly are stainless steel. The spool diameters and
faces are finished with grinding. The sealing surface of the mating housing are finished
ground as well. The T-fitting is forged stainless steel.
Figure 27- Excess Flow Valve - Exploded
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 37
The bill of materials for the Excess Flow Valve Sub-Subsystem is shown in Table 9.
Mass is 0.5 kg and the cost is $23.
Part Numbering
c
CO O~
y? & CO
1 J8 §
0> U) 0)
3 ™ w
3 ff
3
20 00 00
20 01 00
20 02 00
20 02 01
20 02 02
20 02 03
20 02 03
Part Name/Description
| Product Structure
c
w o- o
Sff §- w '
I 1 cf-g^MGO^OlO-^OOCQ^
3 ? "5 r- °
3 ff 2
3
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 38
4.4. Purge Sub-Subsystem
Figure 28 shows all components included in the Purge Sub-Subsystem. All fuel lines
are seamless 316 stainless steel. The flex hose is stainless steel jacketed PTFE. The
T and elbow fittings are forged 316 stainless steel.
Figure 28- Purge Sub-Subsystem - Components.
(Source: FEV, Inc. photos)
The bill of materials for the Purge Sub-Subsystem is shown in Table 10. Mass is 1.5 kg
and the cost is $47.
Part Numbering
CO
co D-
% 1 g
f« yfl C
ffi- ^< CT
0) (/)(/)
3 I I
3 5T
20 00 00
20 01 00
20 02 00
20 02 04
20 02 04
20 02 04
20 02 04
20 02 04
20 02 04
20 02 04
20 02 04
20 02 04
Part Name/Description
Product Structure
co
CO D- o
3 1 g L
& 1 I-S^MGO^OIO^OOCD^
3 Sf "5 i—
3 f ?
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
Purge Sub-Subsystem
Line, Over temperature Relief
Elbow, Over temperature Relief
Hose, Pressure Relief
Tee, Pressure/Temperature Relief
Line, Pressure Relief, Tee to Tee
Purge Line, CNG
Line, Solenoid to Purge Tee
Tee, Box, Purge
QTY
O
c
Q)
-f
1
1
1
1
1
1
1
1
1
1
1
Attribute Data
Mass
|a
-sfr§
,J^ IT
CQ C/) ^
O (/)
239.334
209.889
6.603
1.460
0.122
0.102
0.256
0.112
0.093
0.128
0.466
0.181
Photo
Catalog
Picture
Reference
Numbers
2001
20 02 04
CIMG0037
CIMG0038
CIMG0046
CIMG0047
CIMG0048
CIMG0019
CIMG0050
CIMG0061
Cost
Unit Cost
$47
Table 10- BOM Purge Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 39
5. High Pressure Circuit Subsystem
5.1. Filler (Refueling) Sub-Subsystem
Figure 29 shows all the components included in the Filler Sub-Subsystem.
Figure 29- Filler Sub-Subsystem - Components
(Source: FEV, Inc. photos)
Figure 30 is an exploded view of the fill port (NGV1) mechanism. The body of the fill
port is constructed of stainless steel. The mounting cup for the fill port is injection
molded plastic.
Figure 30- Fill Port - Exploded View
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 40
The bill of materials for the Filler (Refueling) Sub-Subsystem is shown in Table 11.
Mass is 0.6 kg and the cost is $21.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 03 01
20 03 01
20 03 01
20 03 01
20 03 01
20 03 01
20 03 01
Part Name/Description
Product Structure
w o- o
w §. co .
I $ & 51
2 <2.«!T3 -*N>co.^oicn^jooco;i
3 I I i
3
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 41
5.2. Distribution, High Pressure Sub-Subsystem
Figure 31 shows all components included in the Distribution, High Pressure Sub-
Subsystem. All lines are seamless stainless steel (ASTM-213). The elbow and ball
valve are stainless steel as well. Bracket costs were estimated using progressive metal
stamping for high volume production.
Figure 31- Distribution, High Pressure Sub-Subsystem
(Source: FEV, Inc. photos)
The bill of materials for the Distribution, High Pressure Sub-Subsystem is shown in
Table 12. Mass is 2.4 kg and the cost is $64.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 03 01
20 03 02
20 03 02
20 03 02
20 03 02
20 03 02
20 03 02
20 03 02
20 03 02
Part Name/Description
Product Structure
" ^ °
1 || i -
3
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 42
5.3. Filter Sub-Subsystem
Figure 32 represents the Filter Sub-Subsystem.
Figure 32- Filter Sub-Subsystem - Components
(Source: FEV, Inc. photos)
Figure 33 shows an exploded view of the CNG filter. The upper and lower black
anodized housings are billet machined; however forging was assumed for high volume
production of the pressure vessel. The filter is a 'coalescing element composed of an
epoxy saturated, borosilicate glass microfiber tube surrounded by a coarse fiber drain
layer retained by a synthetic fabric safety layer.' (www.parker.com) The 0-rings are
Buna-N and the plastic filter internal components are Acetal plastic.
Figure 33- CNG Filter- Exploded View
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 43
The bill of materials for the Filter Sub-Subsystem is shown in Table 13. Mass is 0.6 kg
and the cost is $18.
Part Numbering
to D-
% 1 g
ffi- ^< CT
0) (/)(/)
3 ro -5
3 5T
20 00 00
20 01 00
20 02 00
20 03 00
20 03 01
20 03 02
20 03 03
20 03 03
20 03 03
Part Name/Description
Product Structure
to D- o
" 1 g L
5T 1 I-S^MCO^OIO^OOCD^
3 2" "Si i—
3 f ?
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Filler (Refueling) Sub-Subsystem
Distribution, High Pressure Sub-Subsystem
Filter Sub-Subsystem
Filter
Bolt, Filter
QTY
O
c
Q)
-f
1
1
1
1
1
1
1
2
Attribute Data
Mass
h
^f-
m= «) S
jl
239.334
209.889
6.603
7.732
0.637
2.387
0.613
0.613
0.030
Photo
Catalog
Picture
Reference
Numbers
2001
20 03 01
20 03 02
20 03 03
CIMG0223
CIMG0224
Cost
Unit Cost
$21
Table 13- BOM Filter Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 44
5.4. Pressure Regulator Sub-Subsystem
Figure 34 shows all the components included in the Pressure Regulator
Subsystem including the bracket, guard, fasteners, regulator, and ground strap.
Sub-
Figure 34- Pressure Regulator Sub-Subsystem - Components
(Source: FEV, Inc. photos)
Figure 35 shows an exploded view of the CNG regulator. The unit produced by GFI is
a single stage regulator. It features coolant heating, integral high pressure solenoid
shut-off, pressure and temperature transmitters. The upper and lower housings are
both die cast. A variety of manufacturing processes are used in creating the internals
including wire forming, machining, injection molding and stamping. Cost considerations
were made for stringent cleanliness requirements needed for this application.
Figure 35- Pressure Regulator - Exploded View
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 45
The bill of materials for the Pressure Regulator Sub-Subsystem is shown in Table 14.
Mass is 4.1 kg and the cost is $78.
Part Numbering
C/5
w §-
4? & W
1 J8 §
0) (/)(/)
3 sr •<
3 5T
3
20 00 00
20 01 00
20 02 00
20 03 00
20 03 01
20 03 02
20 03 03
20 03 04
20 03 04
20 03 04
20 03 04
20 03 04
20 03 04
20 03 04
Part Name/Description
Product Structure
w 7 o
$P §- w '
I 1 1 °
3 jj|--<:^.^K;'co-^ai0)^lo°(Do
3 5T £
3
-3. 0)
239.334
209.889
6.603
7.732
0.637
2.387
0.613
4.095
0.061
1.480
0.027
1.184
1.306
0.037
Photo
Catalog
Picture
Reference
Numbers
2001
20 03 01
20 03 02
20 03 03
20 03 04
CIMG0221
CIMG0222-3
CIMG0225
CIMG0238
CIMG0239
CIMG0240
Cost
Unit Cost
$78
Table 14- BOM Pressure Regulator Sub-Subsystem
6. Low Pressure Circuit Subsystem
6.1. Distribution, Low Pressure Sub-Subsystem
Figure 36 shows all components included in the Low Pressure Distribution Sub-
Subsystem including the brackets used for line mounting. Lines used for CNG transport
are either stainless steel or braided stainless steel reinforced flex lines. Coolant transfer
hoses for the pressure regulator heating circuit are SAE20R3 and the regulator vacuum
reference hoses are SAE30R7.
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 46
Figure 36- Distribution, Low Pressure Sub-Subsystem - Components
(Source: FEV, Inc. photos)
The bill of materials for the Distribution, Low Pressure Sub-Subsystem is shown in
Table 15. Mass is 4.6 kg and the cost is $109.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 04 00
20 04 01
20 04 01
20 04 01
20 04 01
20 04 01
20 04 01
Part Name/Description
Product Structure
w o- o
£. V! -0 -"-NlGOJ^OlCn^JOOCOo
§ B. cr
3 I s
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Low Pressure Circuit Subsystem
Distribution, Low Pressure Sub-Subsystem
Line Cluster, CNG Regulator
Bracket, Rear, Line Cluster, CNG Regulator
Bracket, Mid, Line Cluster, CNG Regulator
Bracket, Front, Line Cluster, CNG Regulator
Line Regulator to Fuel Rail
QTY
O
c
03
3
•t
1
1
1
1
1
1
1
1
1
1
Attribute Data
Mass
Total Mass
(Unit Mass x qty.)
"kg"
239.334
209.889
6.603
7.732
8.622
4.621
3.027
0.396
0.721
0.177
0300
Photo J
Catalog
Picture
Reference
Numbers
2001
20 04 01
CIMG0202
CIMG0250
CIMG0251
CIMG0252
CIMG0222-1
Cost
Unit Cost
$109
Table 15- BOM Distribution, Low Pressure Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 47
6.2. Fuel Rails Sub-Subsystem
Figure 37 shows the Fuel Rail Sub-Subsystem partially disassembled. The fuel injector
has been removed from the assembly to be included in its own sub-system. The wide
upper rail shown in the top center of the image supplies the fuel injector. The lower rail
shown center right of image is a shorter rail that is fed from the injector. The CNG flow
path then travels through a barbed fitting to a rubber hose and finally to an intake
manifold mounted nozzle shown in Figure 38. The nozzle is a straight thru diameter
with no specialized geometry.
Figure 37- Fuel Rails Sub-Subsystem - Components
(Source: FEV, Inc. photos)
Figure 38- Injector Nozzle - Components
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 48
The bill of materials for the Fuel Rail Sub-Subsystem is shown in Table 16. Mass is 3.8
kg and the cost is $74.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 04 00
20 04 01
20 04 02
20 04 02
20 04 02
Part Name/Description
| Product Structure
M & o
f j | H
^ oT 2
3 5
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Low Pressure Circuit Subsystem
Distribution, Low Pressure Sub-Subsystem
Fuel Rails Sub-Subsystem
Bolt, Fuel Rail, CNG
Fuel Rail Assembly, CNG
QTY
O
c
ffl
1
1
1
1
1
1
1
1
Attribute Data
Mass
'c.
in
*it
-3. 0)
239.334
209.889
6.603
7.732
8.622
4.621
3.825
0.077
3.748
Photo
Catalog
Picture
Reference
Numbers
2001
20 04 01
20 04 02
CIMG0215
CIMG0216
Cost
Unit Cost
$74
Table 16- BOM Fuel Rails Sub-Subsystem
6.3. Fuel Injector Sub-Subsystem
Figure 39 shows all components included in the Fuel Injector Sub-Subsystem. One (1)
CNG injector is used for each cylinder.
Figure 39- Fuel Injector Sub-Subsystem - Components
(Source: FEV, Inc. photos)
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 49
CNG rail pressure is 90-110 psig. In comparison, gasoline fuel injector rail pressure is
approximately 55 psig. Lower energy density of CNG requires a higher flow rate. The
construction of the CNG injector is very similar to a gasoline injector with a cost
premium for non-lubricated fuel operation. Figure 40 shows a cross section of the CNG
injector.
Figure 40- CNG Fuel Injector- Sectioned
(Source: FEV, Inc. photos)
The bill of materials for the Fuel Injectors Sub-Subsystem is shown in Table 17. Mass
is 0.2 kg and the cost is $95.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 04 00
20 04 01
20 04 02
20 04 03
20 04 03
Part Name/Description
| Product Structure
w & o
^ & W '
m CO c —I
5> "5 en ° --
3 1 I 1 " M " * ^ " ' "J ' i:>
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Low Pressure Circuit Subsystem
Distribution, Low Pressure Sub-Subsystem
Fuel Rails Sub-Subsystem
Fuel Injectors Sub-Subsystem
Fuel Injector
QTY
D
c
ffl
1
1
1
1
1
1
8
8
Attribute Data
Mass
ji
|s
239.334
209.889
6.603
7.732
8.622
4.621
3.825
0.176
0.176
Photo
Catalog
Picture
Reference
Numbers
2001
20 04 01
20 04 02
CIMG0216-7
CIMG0216-7
Cost
Unit Cost
$95
Table 17- BOM Fuel Injectors Sub-Subsystem
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 50
7. Controls Subsystem
7.1. Control Module Sub-Subsystem
All components associated with the Control Module Sub-Subsystem are identified in
Figure 41. From left to right are the ECU mounting bracket, ECU, Intake Air
Temperature module and Fuel Pump module. The Silverado CNG system utilizes a
separate ECU.
Figure 41- Control Module Sub-Subsystem - Components
(Source: FEV, Inc. photos)
Figure 42 shows the interior of the CNG ECU including both die cast covers, seal,
board and fasteners.
Figure 42- CNG ECU - Exploded View
(Source: FEV, Inc. photos)
ECU circuitry was reviewed in detail. Each board component was identified and costed
individually including assembly cost. Figure 43 and Figure 44 show top and bottom
views of ECU board with number labels matching the table with circuit description.
-------
Analysis Report BAV-P310324-03
June 26, 2015
Page 51
10
8
8
2
ID ECU (Top)
1 Aluminum Capacitor- TMD
2 Aluminum Capacitor-TMD
3 Transistor- TMD
4 IC4pin-SMD
5 1C 4 pin- SMD
6 1C 4 pin- SMD
7 Diode- TMD
8 1C 14 Pin- SMD
9 1C 18 Pin- SMD
10 1C B Pin-SMD
11 Transistor / Voltage Regulator 1C- TMD
12 Transistor / Voltage Regulator 1C- TMD
13 Glass Diode- SMD
14 Resistor- TMD
15 Aluminum Capacitor-SMD
16 Aluminum Capacitor- SMD
17 Aluminum Capacitor- SMD
18 Aluminum Capacitor-SMD
19 Capacitor-TMD
20 1C 3 Pin- SMD
21 Diode 2 Pin- SMD
22 1C 4 pin- SMD
23 1C 2 Pin- SMD
24 1C 16 Pin- SMD
25 1C 4 pin- SMD
26 1C 4 pin-SMD
27 Relay 8 Pin- SMD
28 1C 14 Pin- SMD
29 Crystal 4 pin- SMD
30 Resistor- SMD
31 Resistor- SMD
32 Resistor- SMD
33 Resistor 8 Pin- SMD
34 Capacitor- SMD
35 CPU
36 Board Connector
37 Circuit Board
I
Figure 43- CNG ECU Board with Circuit ID numbers - Top
(Source: FEV, Inc. photos)
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Analysis Report BAV-P310324-03
June 26, 2015
Page 52
ECU Control Board (Bottom)
ECU (Bottom|
Diode 2 Pin- SMD
Glass Diode- SMD
Resistor. SMD
Resistor- SMD
Resistor. SMD
Resistor- SMD
Capacitor- SMD
1C 3 Pin- SMD
Diode 2 Pin- SMD
Quantity
36
49
16
46
150
131
20
.., -,
" *" ' "' '
iJ ••'-
- - !••;•? <.:•. i£-i?j'-si
'. } % • - . v -.-•-.
. • 3 :•:::'*': ,.
• , • * • Tw - • . •
Figure 44- CNG ECU Board with Circuit ID numbers - Bottom
(Source: FEV, Inc. photos)
The bill of materials for the Control Module Sub-Subsystem is shown in Table 18. Mass
is 3.7 kg and the cost is $232.
Part Numbering
w §•
4? & w
a -S &
"> ^
3 If
20 00 00
20 01 00
20 02 00
20 03 00
20 04 00
20 05 00
20 05 01
20 05 01
20 05 01
20 05 01
20 05 01
20 05 01
Part Name/Description
Product Structure
W 0- 0
g & w •
§ a § °* _ --
3 (D ^j [—
3 f ?
3 (D.
Compressed Natural Gas System
Storage Subsystem
Safety Devices Subsystem
High Pressure Circuit Subsystem
Low Pressure Circuit Subsystem
Controls Subsystem
Control Module Sub-Subsystem
ECU, CNG
Bracket, CNG Controller
Fasteners, ECU & CNG controller bracket
Fuel Pump Module, CNG
Intake Air Tempurature (IAT) Module
QTY
D
Q)
.gf
1
1
1
1
1
1
1
1
1
1
1
Attribute Data
Mass
|o!
ft1
m=g!
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Analysis Report BAV-P310324-03
June 26, 2015
Page 53
7.2. Wire Harnesses Sub-Subsystem
Figure 45 shows the components comprising the Wire Harness Sub-Subsystem, main
harness shown left and rearward harness shown right. Both harnesses are dedicated to
the CNG system. The main harness connects the ECU, IAT module, regulator and
injectors. The rear harness connects the main harness, fuel pump, fuel pump module,
as well as high pressure safety lock off connections.
Figure 45- Wire Harness Sub-Subsystem
The bill of materials for the Wire Harnesses Sub-Subsystem is shown in Table 19.
Mass is 2.8 kg and the cost is $71.
Part Numbering
Sub-Subsystem
Subsystem
System
20 00 00
20 01 00
20 02 00
20 03 00
20 04 00
20 05 00
20 05 01
20 05 02
20 05 02
20 05 02
Part Name/Description
| Product Structure
g 7 °
<$ §• co •
I 1 1 -§ ^ co
3 2J" "m i- °
3 & S
3
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Analysis Report BAV-P310324-03
June 26, 2015
Page 54
8. Cost Summary and Conclusion
The primary project objective was to determine net incremental direct manufacturing
costs (NIDMC) for a complete Compressed Natural Gas (CNG) fuel system. The
system selected to represent the light-duty pickup truck segment was a 2013 Chevrolet
Silverado equipped with the bi-fuel option. A NIDMC of $2,276 (Table 20) represents
the calculated cost to the OEM to add a CNG fuel system to an existing gasoline
vehicle. The boundary conditions for the cost analysis included manufacturing in the
United States, high production volume, and a mature and competitive market place.
Not included in the NIDMC are OEM indirect costs such as corporate overhead,
research and develop, and tooling (incremental tooling provide separately in Appendix
A). In addition, there is no OEM profit included in the calculation. Both OEM indirect
costs and profit are added to the FEV calculated NIDMC using an EPA Indirect Cost
Multiplier (ICM). The application of the multiplier was outside the scope of this project.
Table 20 - CNG Subsystem Cost Summary Overview
Subsystem
Storage
Safety Devices
High Pressure
Circuit
Low Pressure
Circuit
Controls
TOTAL
Total Direct
Manufacturing
(i.e., material,
labor and
manufacturing
overhead)
$1,175
$126
$154
$268
$268
$1,959
Total Markup
Cost (i.e., end
item scrap,
SG&A, Profit,
ED&T/R&D)
$177
$24
$28
$38
$35
$302
Total
Packaging
Cost
$9
$1
$3
$2
$1
$15
Net
Incremental
Direct
Manufacturing
Cost
$1,360
$151
$184
$278
$303
$2,276
Additional cost details for each subsystem listed in Table 20 can be found in Appendix
A. As highlighted in Figure 46, the largest contributor to the overall CNG system cost is
the storage system at 60% of the total NIDMC.
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Analysis Report BAV-P310324-03
June 26, 2015
Page 55
Compressed Natural Gas System
I Storage Subsystem
i Safety Devices Subsystem
High Pressure Circuit Subsystem
I Low Pressure Circuit Subsystem
Controls Subsystem
Figure 46- CNG Subsystems
Material cost makes up $1531.20 of the total $2276.20 for the CNG system, most of
which comes from the carbon-fiber wrapped fuel tank. See Figure 47 for a detailed
breakdown.
Compressed Natural Gas System
$107.32^ $45.65
$109.15
$40.20
$15.03
• Material
• Labor
Burden
• End Item Scrap
• SG&A
• Profit
• ED&T-R&D
Packaging
Figure 47- Manufacturing and Mark-up Cost
All costs were developed using a volume assumption of 450,000 units per year. This
cost analysis is inclusive of all associated assembly cost from component to vehicle.
Calculations were performed to determine equipment sizing, cycle times and material
usage requirements. FEV utilized its extensive database of rates for equipment, labor,
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Analysis Report BAV-P310324-03
June 26, 2015
Page 56
material, end item scrap, selling, general and administrative (SG&A), profit, and
engineering, design and testing (ED&T) to develop costs representative of what an
OEM would incur for such a system in high volume automotive manufacturing.
Costs were developed for all critical components by detailing each operation in a
Manufacturing Assumptions Quote Sheet (MAQS). Process calculators were used to
determine equipment size and corresponding rate ($/hr), cycle time (seconds) and
material usage (kg). For example, the Pressure Regulator Cap was identified as an
aluminum die casting. The number of slide pulls, cavities, part width, part height,
average wall thickness, parting line area, cavity surface area, and max wall thickness
were all used to determine the die-casting machine size, cycle time and material usage.
This information was then transferred to the MAQS where rates are pulled in for
material, labor, manufacturing overhead/burden, end item scrap, SG&A, profit, and
ED&T. Cost contributions are then calculated for these core cost elements. Similar
process calculators are used for subsequent processing such as machining, where all
machine features are measured, speed and feed rates assigned based on the
respective material, and feed times calculated. In addition pallet changes, tool changes,
rapid times, as well as estimated work pieces per fixture are used to estimate the total
cycle time. Finally all processes are summed, end item packaging estimated, and total
cost calculated. Cost contributions for the core cost elements are then linked to the
Cost Model Analysis Template (CMAT). The CMAT incorporates cost data from various
Sub-Subsystems into one summary sheet. For detailed cost breakdown, see Appendix
A
Overall system costing methods are either calculated or commodity. All fastening
hardware (bolts, washers, nuts, etc...) come from online bolt manufacturer's pricing.
Commodity pricing was also used on small components within larger assemblies such
as the ECU circuits and components within assemblies like the pressure regulator. For
example commodity pricing was referenced to estimate costs for components like
springs, seals, solenoids, and diaphragms.
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Report FEV-P310324-03
June 26, 2015
Page 57
9. Appendix A
The CNG system level cost summary, by major components and assemblies, is shown below in Table 21.
Table 21 - Complete Cost Summary (CMAT) - CNG System
BASE TECHNOLOGY GENERAL PART
INFORMATION
g
1
2
3
4
5
P
P tt ^
S s* -S
i-. w =
B -S I»
.
1
a
03
Component
Nam e/De scrip tion
20 Compressed Natural Gas System
| 01 Storage Subsystem
01
02
03
Tank Cover Sub-Subsystem
Cradle Sub-Subsystem
Tank Sub-Subsystem
I 02 Safety Devices Subsystem
01
02
03
04
High Pressure Lock-Off Valve Sub-Subsystem
Safety Relief Valve Sub-Subsystem
Excess Flow Valve Sub-Subsystem
P.'ce S..'j-i..::;svs'.em
| 03 Hiqh Pressure Circuit Subsystem
01
02
03
04
Filler (Refueling) Sub-Subsystem
Distribution
High Pressure Sub-Subsystem
Filter Sub-Subsystem
Pressure Regulator Sub-Subsystem
| 04 Low Pressure Circuit Subsystem
01
02
03
Distribution
Low Pressure Sub-Subsystem
Fuel Rails Sub-Subsystem
Fuel Injectors Sub-Subsystem
| 05 Controls Subsystem
01
02
Control f/odule Sub-Subsystem
Vv H -a"J5ir; ; .-jo. iv'S.^r.
TOTAL
BASE TECHNOLOGY PACKAGE COST INFORMATION
Manufacturing
Material
978.16
70.61
134.40
773.15
73.53
19.81
7.35
9.13
37.25
99.36
5.12
46.40
681
41.03
140.91
82.05
46.46
12.40
221.24
192.11
29.14
1,513.20
Labor
53.04
3.51
11.74
37.79
17.06
6.75
4.40
3.98
1.93
21.38
554
3.23
3.65
8.96
24.01
4.36
7.07
12.59
23.89
237
21.51
13938
Burden
143.33
4.13
11.10
128.10
35.14
17.60
9.28
5.96
229
33.13
6.86
3.78
710
15.40
72.11
5.28
874
58.10
22.57
885
13.72
30628
Total
Manufacturing
Cost
(Component/
Assembly)
-
1.174.53
78.25
157.24
939.04
125.72
44.15
21.03
19.07
41.47
153.87
17.52
53.42
17.55
65.38
237.03
91.69
62.26
83,08
267.70
203.33
64.36
1,958.86
Markup
End Item
Scrap
35.11
0.46
1.19
33.46
1.27
0.73
0.25
0.11
0.17
1.22
0.10
0.30
023
0.58
1.28
0.51
0.38
0.38
1.32
1.11
0.21
4020
SG8A
61.97
6.52
13.80
4165
9.47
379
1 73
1.51
243
11.01
1.44
3.49
129
479
13.76
5.81
4,10
3,84
12.94
1018
277
10915
Profit
58.03
5.62
13.97
38.45
9.25
3.93
1.83
1.37
2.12
11.17
1 23
3.56
1 14
5.24
14.80
6.00
4.41
4.39
14.07
11.51
2.55
10732
ED8.T-R8.D
21.86
1.33
4.51
16.02
4.31
2.11
1.00
0.45
0.75
4.25
0.29
1.47
0.35
2.14
3.53
2.52
2.71
3.30
6.70
5.63
1.06
45.65
Total Markup
Cost
(Component/
Assembly)
-
176.98
13.92
3347
129.58
24.29
10.56
4.81
3.45
5.47
27.65
3.05
8.83
3.01
12.76
38.36
14.84
11.60
11.92
35.03
28.44
6.60
302.32
Total
Packaging
Cost
(Component
/Assembly)
8.84
1.33
2.65
4.86
0.52
0.24
0.16
0.06
0.06
2.75
0.26
1.97
0.19
0.32
2.38
1.97
0.39
0.02
0.53
0.19
0.34
1503
Net
Component/
Assembly
Cost Impact to
OEM
-
1.360.35
93.50
193.37
1,073.48
150.54
54.95
25.99
22.59
47.01
184.27
20.83
64.22
20.76
78.47
277.78
108.50
74.26
95.02
303.26
231.96
71.30
2,276.20
Tooling (x1 000)
5,242.012.93
1.990,310.80
2,591.702.13
660.000.00
5.388.063.40
2,948,929.80
2.403,133.60
36,000.00
4,010,710.40
330.386.80
248.695.00
1.328,630.20
2.102.998.40
1,489,698.00
577.268.40
901,429.60
11.000.00
1,687,144.10
1.047,144.10
640. DC ' , .
17.817,628.83
Investment
(X1000)
5.242,012.93
1,990,310.80
2,591,702.13
660.000.00
5,388,063.40
2.948,929.80
2.403,133.60
36,000.00
4,010,710.40
330.386.80
248.695.00
1.328,630.20
2.102.998.40
1,489,698.00
577.268.40
901,429.60
11.000.00
1,687,144.10
1.047.144.10
640.000.00
17,817.628.83
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