Complete Procedure for Handling a LPG Tanker Accident

With the rapid growth of global energy transportation, LPG Tanker Trailers have become an essential solution for transporting liquefied petroleum gas across regions and countries. Due to the flammable and pressurized characteristics of LPG, any accident involving an LPG tanker trailer requires immediate and professional emergency handling procedures.

According to industry safety reports, LPG transportation accidents are relatively rare because modern LPG tank trailers, especially INTAI LPG tank trailers, are engineered with advanced safety systems, including emergency shut-off valves, pressure relief devices, anti-corrosion protection, and high-strength tank structures. With strict manufacturing standards and reliable safety designs, INTAI LPG tank trailers help reduce operational risks during LPG transportation. However, when accidents occur, incorrect handling can still increase risks such as gas leakage, fire, explosion, and environmental damage.

To improve transportation safety, drivers, operators, and emergency teams must understand the complete procedure for handling a LPG tanker trailer accident.

Three Typical Types of LPG Tanker Trailer Accidents and Associated Risks

Accident Without Leakage

Scenario: The vehicle is involved in a collision, rear-end accident, or rollover. The outer shell of the tank remains intact, and there is no LPG leakage.

Risks:

• The tank structure may be damaged, reducing its pressure-bearing capacity.
• Continuous exposure to sunlight or rising ambient temperatures can cause the saturated vapor pressure inside the tank to keep increasing.
• This may suddenly trigger the safety valve to open, resulting in rapid pressure release and potential combustion or explosion.

Leakage Accident

Scenario: A traffic accident damages valves, pipelines, or the tank body, causing vapor-phase leakage or liquid-phase spray leakage.

Risks:

• After LPG vaporizes, its density is higher than air, causing it to accumulate in low-lying areas.
• When the leaked gas encounters static electricity, open flames, or vehicle sparks, it can form an explosive gas-air mixture, creating a severe explosion hazard.

Leakage, Fire, and Explosion Accident

Scenario: The leaked LPG comes into contact with an ignition source and catches fire, or even causes a deflagration/explosion. Another possible cause is overheating caused by prolonged downhill braking or tire fires, resulting in continuous high-temperature heating of the tank.

Risks:

• Direct flame exposure can heat the tank rapidly.
• The internal pressure may rise sharply within a short period.
• This can lead to a physical tank explosion with extremely destructive consequences.

Nine Standard Emergency Response Procedures (Operations and Safety Precautions)

1. Cooling and Temperature Reduction (Basic Emergency Measure for All Accident Types)

Applicable situations: Tank overheating, LPG leakage, fire incidents, or tire fires heating the tank.

Operation: Use a fog water spray system to completely cover the tank surface and continuously spray water to reduce tank temperature and internal pressure, preventing tank rupture caused by excessive heat.

Key precautions:

1. Ensure the entire tank is cooled evenly and avoid localized overheating.
2. For overturned fully filled tanker trailers, do not directly spray water onto the safety valve. Low-temperature water may freeze and block the safety valve, preventing pressure release and increasing the risk of tank explosion.
3. Do not use high-pressure direct water jets, as water impact on metal surfaces may generate static electricity.

2. Dilution and Suppression(Dedicated Method for Leakage Control)

Applicable situations: Gas-phase or liquid-phase LPG leakage and large-scale gas diffusion.

Operation: Use fog water guns or water curtains to create a water mist barrier, continuously diluting LPG concentration in the air until it falls below the lower explosive limit.

Key precautions:

1. Do not use direct water streams. Water impact on metal surfaces may generate static sparks.
2. Ground all metal components. Connect grounding wires to the rear section of the tank and valve box, and bury them deeply into the ground to eliminate static electricity generated by spraying.
3. Rescue personnel must wear anti-static clothing and non-metallic safety shoes. Non-explosion-proof communication equipment is prohibited inside the restricted area.

3. Valve Closing and Material Cut-Off(Preferred Method for Controlling the Leakage Source)

Applicable situations: Leakage caused by damaged valves or pipelines when the emergency shut-off system remains functional.

Operation: Close the hydraulic emergency shut-off valve to cut off the LPG supply route and stop further leakage.

Key precautions: If the hydraulic shut-off valve fails, use non-sparking tools under water mist protection and choose one of the following methods to release hydraulic pressure:

1. Disconnect the hydraulic oil supply line.
2. Break the fusible plug on the oil pipeline. Once hydraulic pressure drops to zero, the emergency shut-off valve will automatically close.

4. Leak Sealing and Blocking (For Small and Controllable Leaks)

Applicable situations: Small pipeline leaks, valve packing leakage, or minor tank damage without large-scale spray leakage.

Operation: Use magnetic pressure sealing devices, steel band clamps, wooden wedges, inflatable sealing pads, and other professional tools to block the leakage.

Key precautions:

1. No ignition sources are allowed during the entire operation. All tools must be explosion-proof and spark-free.
2. LPG has an extremely low temperature during expansion, which may cause steel embrittlement. Do not strike or forcibly impact the tank with metal tools.
3. Direct sealing is not recommended for high-pressure liquid-phase spray leakage. Priority should be given to controlled venting or LPG transfer.

5. Controlled Venting and Hazard Elimination (Final Option When the Tank Cannot Be Sealed)

Applicable situations: Large-area tank damage, failed leak sealing, and no available tank transfer conditions.

Operation: Continuously cool the tank while using water mist dilution to allow the remaining LPG to naturally discharge safely.

Key precautions:

1. Determine wind direction in advance, establish a large safety zone, and evacuate personnel from low-lying areas.
2. Control vapor discharge speed to prevent static electricity caused by high-speed gas flow.
3. Set up water curtains on the downwind side for continuous dilution. If lifting equipment is available, transport the tank after pressure release.

6. LPG Transfer to Another Tank (The Most Effective Method for Eliminating the Hazard Source)

Applicable situations: The tank remains intact, leakage is controllable, and a safe empty tanker trailer and professional equipment are available.

Operation: Use pressure difference or explosion-proof pumps to transfer LPG from the damaged tanker into a safe empty tank.

Key precautions:

1. The operation must be evaluated by hazardous chemical experts or firefighting professionals, and only certified personnel are allowed to perform the transfer.
2. If the LPG contains butadiene components, oxygen exposure may cause self-polymerization and explosion risks. The tank and pipelines must be inerted with nitrogen to isolate oxygen.
3. Firefighters should continuously use water spray on the downwind side to dilute small amounts of escaping gas.
4. Continuously monitor combustible gas concentration throughout the operation.

7. Controlled Burning Through Guided Discharge (Use with Extreme Caution)

Applicable situations: Stable leakage, limited gas diffusion range, and no nearby dense population areas or buildings.

Operation: Connect a discharge pipe to guide LPG to an open and safe area, then ignite it under controlled conditions to consume the released gas.

Key precautions:

• Do not actively ignite leaked LPG when gas has spread widely or near villages, highways, or residential areas.
• Improper ignition may cause large-scale flash fire, explosion shock waves, and mass casualties.

8. Lifting and Transportation of the Accident Tank

Applicable situations: The site does not allow LPG transfer or controlled venting, and the tank must be moved to a specialized facility for treatment.

Operation: Use professional lifting equipment to hoist the tank and transport it using a flatbed trailer.

Key precautions:

1. Apply grease to the surface of steel wire ropes to reduce friction and prevent sparks.
2. If LPG remains inside the tank, never use a single-point lifting method. Use multiple lifting points with balanced securing to prevent swinging or falling.
3. Before lifting, check internal tank pressure. If pressure is excessive, cool and release pressure first. Lifting is only allowed after safety requirements are met.

9. Safety Escort During Tanker Trailer Relocation

Responsible departments: Firefighting and traffic police work together to provide coordinated protection.

Operation procedure:

• Traffic police vehicles lead the route and clear surrounding traffic.
• Heavy-duty fire water trucks follow behind to monitor the tanker and provide emergency cooling if necessary.
• Control ignition sources along the route.
• Avoid densely populated areas, tunnels, fuel stations, and other high-risk locations.

Summary of Prohibited Actions During LPG Tanker Trailer Accident Response

1. Do not extinguish the flame blindly when the leakage source has not been sealed.

If an LPG tanker trailer is on fire, the leakage source must be controlled first. Extinguishing the flame without stopping the gas release may cause continuous gas accumulation and create an explosion hazard.

2. Do not allow localized dry heating during tank cooling, and never directly spray water onto the safety relief valve of a fully filled LPG tank.

Uneven cooling may damage the tank structure, while direct water spraying on the safety valve of a liquid-filled tank may affect normal pressure relief operations.

3. Do not use iron tools, wear nailed shoes, or operate non-explosion-proof electrical equipment in the leakage area

Any impact sparks, static electricity, or electrical sparks may ignite LPG vapor and trigger a fire or explosion.

4. Do not perform ignition or controlled burning operations in large-scale LPG diffusion areas

When LPG gas spreads over a wide area, intentional ignition is strictly prohibited because it may cause uncontrolled combustion or explosion.

5. Do not forcefully block leakage or strike the tank wall when the LPG tanker trailer is under pressure

Applying external force to a pressurized tank may damage the pressure vessel structure and increase accident risks.

6. Do not conduct LPG transfer operations without nitrogen inerting procedures.

Before transferring LPG from one tank to another, nitrogen inerting must be completed to reduce the risk of fire, explosion, and oxygen-related hazards.

7. Do not lift or transport a tank with abnormal pressure before pressure relief.

A pressurized LPG tank must be safely depressurized and confirmed stable before any lifting or relocation operation is allowed.

Conclusion

Handling an LPG tanker trailer accident requires a strict and systematic emergency procedure. From immediate evacuation and leakage assessment to professional rescue operations and post-accident inspection, every step plays an important role in protecting people, equipment, and the environment.

Safety is always the top priority in LPG transportation. With proven manufacturing standards and continuous innovation, INTAI LPG tank trailers have become a trusted choice for global customers. Recent, clients from many countries visit INTAI’s factory to experience our production strength and order high-quality LPG tank trailer solutions.

Choose INTAI as your trusted LPG transportation partner for safer and more efficient gas transport solutions.