27 Feb Cold Weather Hazards of Propane-Fueled Vehicles

Cold Weather Hazards of Propane-Fueled Vehicles

Propane-powered vehicles and equipment require special precautions when moved from cold outdoor conditions into a heated building. Propane is stored as a liquid under pressure, and liquid propane expands as its temperature increases. If a fuel container is overfilled, warming can increase internal pressure and cause the pressure-relief valve to discharge propane vapor.

Released propane can create a serious fire or explosion hazard if it accumulates and reaches an ignition source.

Before Bringing a Propane-Fueled Vehicle Indoors

Before moving propane-fueled equipment into a building:

• Inspect the propane fuel system for leaks, damage, or loose connections.
• Follow the vehicle, fuel-container, and propane-system manufacturer’s inspection procedures.
• Use an approved propane leak-detection solution or properly calibrated combustible-gas detector when checking for leaks.
• Never use a flame to check for propane leaks.
• Verify that the fuel container has not been overfilled.
• Ensure valves, hoses, fittings, and the pressure-relief device are in good condition.
• Do not bring equipment indoors when a propane leak is suspected or detected.

Propane containers are generally designed to maintain adequate vapor space for liquid expansion and must not be filled beyond their permitted filling limit. Follow the container manufacturer’s requirements and applicable propane-filling procedures rather than attempting to determine the liquid level by intentionally releasing propane.

Do Not Bleed Propane to Check the Tank Level

Do not disconnect a fuel line or intentionally open a valve to determine whether a propane container is overfilled. Releasing propane can expose employees to extremely cold liquid or vapor, which can cause frostbite, and can create a flammable atmosphere.

If a container is suspected of being overfilled:

• Keep the vehicle or equipment outdoors and away from ignition sources.
• Do not intentionally vent propane to the atmosphere.
• Do not attempt to reduce the level by improvised methods.
• Have the container evaluated and corrected by trained and authorized personnel using approved procedures.

Servicing Propane-Fueled Vehicles

Before performing maintenance or repairs, follow the manufacturer’s procedures for shutting down and isolating the propane fuel system.

Where appropriate, this may include:

1. Close the fuel shutoff or service valve.
2. Follow the manufacturer’s procedure for removing or consuming propane remaining in the fuel line.
3. Shut down the engine and prevent accidental startup.
4. Apply required lockout/tagout procedures before servicing equipment where unexpected energization could cause injury.
5. Keep ignition sources away from the work area.

Never loosen fittings or disconnect pressurized propane lines unless the system has been properly isolated and the work is performed according to approved procedures.

Restoring the Fuel System

After service or repair:

• Verify that all components and fittings have been properly reassembled.
• Restore the fuel supply according to the manufacturer’s instructions.
• Open manually operated service valves slowly when required by the equipment manufacturer.
• Check the entire affected system for leaks before returning the equipment to service.
• Never operate equipment when a propane leak is detected.

If an excess-flow device activates, follow the manufacturer’s procedure for resetting and restoring the system rather than repeatedly manipulating the valve.

If Propane Is Released Indoors

Propane vapor is heavier than air and may accumulate near floors, pits, drains, and other low areas. If a significant propane release occurs:

• Warn others and evacuate the affected area.
• Do not operate electrical switches, equipment, vehicles, or anything else that could create a spark.
• Eliminate ignition sources only when this can be done safely without entering the hazardous area.
• Do not smoke or use open flames.
• Contact the appropriate emergency personnel.
• Shut off the propane supply only if it can be done safely.
• Ventilate the area using established emergency procedures and equipment suitable for a potentially flammable atmosphere.
• Prevent entry until the area has been evaluated and determined safe.

Do not rely on the disappearance of propane odor to determine that an area is safe. Atmospheric testing may be necessary before employees re-enter or ignition sources are restored.

Prevent Fires and Explosions

When propane-powered equipment is stored or serviced indoors:

• Maintain required ventilation.
• Keep the area free of open flames, sparks, smoking, and other ignition sources.
• Protect propane containers and fuel systems from physical damage.
• Maintain appropriate fire extinguishers and emergency equipment.
• Never perform unauthorized modifications to propane fuel systems.
• Follow facility procedures for indoor storage and servicing of propane-fueled equipment.
• Ensure employees performing propane-system work are properly trained and authorized.

Remember

Moving propane equipment from a cold environment into a warm building can increase container pressure. Inspect for leaks, verify the fuel system is safe, never intentionally vent propane as a level check, control ignition sources, and follow manufacturer-approved servicing procedures.