waste management cng vehicles. objectives the student will be able to… define cng and it’s...
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Waste Management CNG Vehicles
Objectives
The student will be able to…
• Define CNG and it’s Hazards• Understand CNG Cylinder Limitations• Identify CNG WM Vehicles• Identify locations of CNG cylinders on WM
Vehicles• Understand the Hazards of CNG on WM
Vehicles• Mitigate the Hazards
The student will be able to…
• Define CNG and it’s Hazards• Understand CNG Cylinder Limitations• Identify CNG WM Vehicles• Identify locations of CNG cylinders on WM
Vehicles• Understand the Hazards of CNG on WM
Vehicles• Mitigate the Hazards
What is CNG?
Acronyms:
CNG (Compressed Natural Gas)
NG (Natural Gas)
LNG (Liquefied Natural Gas)
Acronyms:
CNG (Compressed Natural Gas)
NG (Natural Gas)
LNG (Liquefied Natural Gas)
CNG General Properties
• Gas comprised of mostly Methane 90-99 %• Remaining amounts are Ethane, Propane,
Pentane, CO, Nitrogen and CO2
• Gas comprised of mostly Methane 90-99 %• Remaining amounts are Ethane, Propane,
Pentane, CO, Nitrogen and CO2
Ethane4%
Propane2%
Other Inert gasses
4%
Methane90%
CNG General Properties cont.
• CNG is Compressed to 3600 psi
• Odorized
• Non-toxic
• Three basic Hazards to CNG:– Extreme cold– Fire– Asphyxiation
• CNG is Compressed to 3600 psi
• Odorized
• Non-toxic
• Three basic Hazards to CNG:– Extreme cold– Fire– Asphyxiation
CNG General Properties cont.
• Is NG Safer than Gasoline?
– Natural Gas point of ignition is over 2 times higher than gasoline, making NG harder to ignite
– NG Ignites from 1000 – 1350 degrees F while gasoline only requires 475 – 495*F
– Although near perfect conditions must be met for complete combustion, 5-15% air/fuel ratio, a FLASH can be just as dangerous!
• Is NG Safer than Gasoline?
– Natural Gas point of ignition is over 2 times higher than gasoline, making NG harder to ignite
– NG Ignites from 1000 – 1350 degrees F while gasoline only requires 475 – 495*F
– Although near perfect conditions must be met for complete combustion, 5-15% air/fuel ratio, a FLASH can be just as dangerous!
CNG Cylinders
• Must be manufactured to – U.S.D.O.T – NGV-2 – FMVSS (Federal Motor Vehicle Safety
Standards) specifications
• Must be manufactured to – U.S.D.O.T – NGV-2 – FMVSS (Federal Motor Vehicle Safety
Standards) specifications
CNG Cylinders Cont.
The PRD (pressure relief device)
• Every tank must be equipped with a PRD built into the tank valve
• PRD is set to release – In the event of a fire– If tank exceeds
5,000 or 7,500 Psi
The PRD (pressure relief device)
• Every tank must be equipped with a PRD built into the tank valve
• PRD is set to release – In the event of a fire– If tank exceeds
5,000 or 7,500 Psi
Identify CNG WM Vehicles
• ALL natural gas powered vehicles are required to display fuel designation labels at both the LEFT FRONT and RIGHT REAR of vehicle to inform officials and emergency responders of fuel type!
• ALL natural gas powered vehicles are required to display fuel designation labels at both the LEFT FRONT and RIGHT REAR of vehicle to inform officials and emergency responders of fuel type!
Location of CNG Cylinders
• CNG Cylinders are located on the top of the garbage containment portion of the WM truck.
• Cylinders will run lengthwise on longer vehicles and widthwise on shorter vehicles.
• CNG Cylinders are located on the top of the garbage containment portion of the WM truck.
• Cylinders will run lengthwise on longer vehicles and widthwise on shorter vehicles.
Hazards of CNG on WM Vehicles
• Vehicle accident may cause a cylinder rupture• Gas Leak• NG trapped in a confined space can pose a
serious explosion hazard• NG VAPOR is extremely flammable• Vapor is slightly lighter than air• Vapor will rise slowly when leaked into
atmosphere
• Vehicle accident may cause a cylinder rupture• Gas Leak• NG trapped in a confined space can pose a
serious explosion hazard• NG VAPOR is extremely flammable• Vapor is slightly lighter than air• Vapor will rise slowly when leaked into
atmosphere
Mitigating the Hazards
Cylinder or Hose Rupture
• Control ignition sources• Keep cylinder cool with hose stream• Maintain Distance• At 3600psi CNG
leaking from a small orifice can cut through skin.
Cylinder or Hose Rupture
• Control ignition sources• Keep cylinder cool with hose stream• Maintain Distance• At 3600psi CNG
leaking from a small orifice can cut through skin.
Mitigating the Hazards Cont.
Small Gas Leak
• WM vehicle is equipped with gas sensors– Cab area– Doghouse (Engine Compartment)– Driver is alerted to trace and significant fuel
leaks
Small Gas Leak
• WM vehicle is equipped with gas sensors– Cab area– Doghouse (Engine Compartment)– Driver is alerted to trace and significant fuel
leaks
Mitigating the Hazards Cont.
Fuel Shut-Off
• There are three fuel shut off systems– Automatic– Manual Pressure Reducer Switch– Manual Cylinder valve shut-off
Fuel Shut-Off
• There are three fuel shut off systems– Automatic– Manual Pressure Reducer Switch– Manual Cylinder valve shut-off
Mitigating the Hazards Cont.
Shut down Fuel Manual Switch
• Identify the Fuel Pressure Regulator
• Located on the driver’s side near the frame rail
Shut down Fuel Manual Switch
• Identify the Fuel Pressure Regulator
• Located on the driver’s side near the frame rail
Mitigating the Hazards Cont.
Identify Fuel Pressures
• Identify high pressure gauge on Left– Operating pressure
3000 psi
• Identify low pressure gauge on Right – Operating pressure
125 psi
Identify Fuel Pressures
• Identify high pressure gauge on Left– Operating pressure
3000 psi
• Identify low pressure gauge on Right – Operating pressure
125 psi
Mitigating the Hazards Cont.
Shut down Fuel
• Identify shut off valve• Notice the “On” position
• Turn Valve to “Off” then monitor high pressure gauge for movement to indicateleak
• Notice the “Off” position
Shut down Fuel
• Identify shut off valve• Notice the “On” position
• Turn Valve to “Off” then monitor high pressure gauge for movement to indicateleak
• Notice the “Off” position
Mitigating the Hazards Cont.
If Manual Cylinder Valve Shut-off
• Each cylinder has it’s own shut-off valve on top of the vehicle
Note: The system is designed to shut off at the pressure reduction valve so you do not have to use the manual valve
If Manual Cylinder Valve Shut-off
• Each cylinder has it’s own shut-off valve on top of the vehicle
Note: The system is designed to shut off at the pressure reduction valve so you do not have to use the manual valve
Mitigating the Hazards Cont.
IMPORTANT NOTE!!!
It is very important on all natural gas vehicles to leave both driver’s and passenger side windows cracked open at least ½ inch to help minimize the possibility of fuel leakage filling cab in the event of a fuel leak !
IMPORTANT NOTE!!!
It is very important on all natural gas vehicles to leave both driver’s and passenger side windows cracked open at least ½ inch to help minimize the possibility of fuel leakage filling cab in the event of a fuel leak !
Questions?
Chief Hinckley
831-901-4112
Chief Hinckley
831-901-4112