Safe handling of gas cylinders

Even in small work places and even just with one or two gas cylinders, unsecured storage of gas cylinders can cause incidents with very serious consequences.

Incident / Issue Description:

Three UK construction firms must pay £685,787 ($AU1,142,803) in fines and costs after a plumber died and six other workers were seriously injured by high-pressure gas cylinders as they rocketed at speeds of up to 170 mph (273 kph) after one toppled over and collided with others, which set off a frightening chain reaction.

It was found that 80 cylinders were stored without their safety-critical protection caps and left without being properly secured in racks. One or more of these cylinders was de-stabilised and probably fell over, causing its unprotected valve to shear off near the cylinder neck releasing an uncontrolled high pressure jet of liquified gas the force of which caused the cylinder to move, colliding with others.

A chain reaction developed rapidly and for several minutes shocked and terrified workers desperately sought shelter as they endured a barrage of heavy cylinders rocketing around them. This continued until 66 of the 80 cylinders had been discharged with sufficient energy to penetrate walls and ceiling voids, travelling into more remote parts of the building.

Causes:

Even in small work places and even just with one or two gas cylinders, unsecured storage of gas cylinders can cause incidents with very serious consequences.

What should you do?

• Ensure there are no unsecured gas cylinders in your workplace.
• Ensure that all persons involved in handling, storage or use of gas cylinders are trained in the safety aspects of gas cylinders.
• Do not remove or tamper with the cylinder valve any time. Removing fittings under pressure may result in serious personal injury as fittings may be projected at high velocity.
• Cylinders must be secured vertically by cylinder wall brackets, before ancillary equipment is connected. Cylinders should always be stored vertically. Portable systems shall remain secured to the cylinder trolley.
• Always close the cylinder valve before relocating the cylinder.
• When using a cylinder trolley to move cylinders, make sure cylinders are properly secured, and the cylinder valves are closed.
• DO NOT transport cylinders with regulators or equipment attached even if the cylinder valves are closed unless on a purpose designed trolley or carrier complete with webbing retainers.
• General purpose trolleys should only be used if there is no other means available. Remove the pressure regulators and ancillary equipment and secure the cylinder.
• Store gas cylinders in areas with good ventilation
• Forklift gas cylinders are fitted with relief valves designed to face upwards in the upper portion of the cylinder where the vapour space is. When a cylinder is placed upside down, the relief valve may be submerged within the liquid of the lower portion of the cylinder. This can cause liquid content to be discharged if the relief valve opens as a result of excessive pressure, such as during a fire or in high temperatures.

When transporting gas cylinders by road

Care should be taken when transporting cylinders whether full or empty.  Never place compressed gas cylinders in the cab.

Open type vehicles

Gas cylinders should be stored and transported in vehicles with cargo areas open to the air, and not stored inside closed type vehicles. When storing or transporting fuel gas cylinders, ensure:

• main cylinder valves are tightly closed
• there is no leakage from the main valve area (eg using a gas detector or soapy water test)
• the cylinders total weight should not exceed 250 kg.
• cylinders are secured in an upright position to prevent them tipping or falling over, apply at least two horizontal straps, as shown.
• cylinders cannot be struck by other objects (eg loose tools and materials)
• cylinders are always removed from the vehicle before the gas is used
• at least one 10B dry-powder fire extinguisher is fitted in the driver’s cabin.

If transporting cylinders lying down:

• Place the cylinders lengthwise on the deck.
• Place the cylinders on chocks to prevent them rolling sideways and to provide more grip to stop them sliding.
• Position the cylinders with the valves facing rearwards, with the base blocked against the headboard or another strong part of the load.
• Apply at least one tie-down strap, as shown below.
• Flammable gas cylinders must not be carried horizontally on steel-floored vehicles (must be on chocks and secured to prevent sparks and subsequent ignition of gas).
• The transportation or storage of acetylene cylinders horizontally should be avoided.
• Where acetylene cylinders have been transported or stored horizontally, the cylinder should be allowed to stand upright for a minimum of 12 hours prior to use. This will allow the acetone to evenly re-distribute within the cylinder and prevent acetone being carried in to the flame.

Closed type vehicles

Closed-type vehicles are vans, utilities and other vehicles that have cargo areas with restricted natural air movement and ventilation. This includes vehicles where gas cylinders are stored under canopies, inside service bodies or toolboxes, and vehicles where cylinders are covered by tarps or tonneau covers.

If you cannot avoid using a closed-type vehicle, it should be fitted with a separate gas storage cabinet that is vapour-tight from the rest of the vehicle.

The gas cabinet must be secured to the vehicle and be big enough to store all cylinders carried in the vehicle, including empty cylinders. It must be designed to ensure gas from leaking cylinders cannot accumulate inside the cabinet but is vented to the atmosphere outside the vehicle. The cabinet door must be securely sealed whenever cylinders are stored in the cabinet.

The cabinet must have:

• one or more permanent vents at the bottom of the cabinet (either floor or side), internal diameter of at least 25mm
• vents located so they cannot be blocked when the cylinders are in the cabinet
• a way of securing cylinders in an upright and stable position (eg straps)