Welding Gas Cylinder Safety: Moving and Securing Cylinders

Cylinder safety rules at a glance

A welding gas cylinder is a vessel under high pressure, usually 150–200 bar (about 2,200–2,900 psi), and newer cylinders go up to 300 bar (about 4,350 psi). A damaged valve or a cylinder that falls over is a real risk of injury, and a gas leak in a closed room or a car can displace the air. That is why all the rules come down to four things:

• the cylinder stands upright, valve at the top, and is secured against falling over,
• you do not drag, roll or drop it; you move it on a cylinder trolley, even over a short distance,
• the valve is closed whenever you are not welding, and for transport you remove the regulator and fit the cap,
• the cylinder does not heat up and has ventilation around it.

These points come from the safety data sheets that gas suppliers issue for every gas, and from the transport guidance of the gas industry. Workplace rules on how cylinders are used, stored and inspected differ from country to country, so for the details that apply to you, ask your gas supplier or your local health and safety authority. The hazards in a home workshop are the same as in a factory, so the same habits make sense there too.

Securing a cylinder on a welding cart

A welding cylinder cart, or a welding cart with room for a cylinder, meets two requirements at once: the cylinder is held upright and you can move it without rolling it. The argon safety data sheet also recommends keeping the valve cap or valve guard on until the cylinder is secured against a wall or bench, in a rack or on a trolley and is ready for use.

When you secure the cylinder, check three things:

• the cylinder stands on the base of the cart and does not hang from its restraint,
• the restraint holds the cylinder firmly and is fixed to the load-bearing frame of the cart, not to a thin panel,
• the restraint and the rest of the fastening are kept away from the arc and spatter; replace anything scorched or damaged straight away.

Do not roll the cylinder to where you need it; move it on the cart or a cylinder trolley. On stairs and when loading it into a vehicle, you need a second person or lifting equipment.

Storage and ventilation

The safety data sheets for argon and CO2 say it plainly: store cylinders upright, secured against falling over, in a well-ventilated place, below 50 °C (122 °F), away from sources of heat and ignition, and not together with flammable materials.

In practice this means the cylinder does not stand next to a heater or a radiator or in full sun, and spatter must not land on it while you weld. Close the valve after every use, even if the regulator stays connected.

Argon and CO2 are not flammable, but they are heavier than air: the relative density of argon is 1.38 and of CO2 1.52. If there is a leak, the gas collects low down, in pits and basements, and displaces the oxygen. So do not store cylinders in a basement or over an inspection pit, and in an enclosed room make sure there is a flow of air.

Carrying cylinders in a car or van

In Europe, the carriage of dangerous goods by road, including gases in cylinders, is based on the ADR agreement, which countries apply through their own law. ADR section 1.1.3.1 (a) exempts carriage by private individuals where the goods are packaged for retail sale and intended for personal or domestic use or leisure, provided that measures are taken to prevent any leakage. Whether a particular cylinder and journey fall under that exemption depends on your country and your situation, so confirm it with your gas supplier or local authority. If you carry cylinders as part of a business, different rules apply.

The exemption does not remove the need for care. EIGA, the European Industrial Gases Association, and gas suppliers recommend:

• ideally an open vehicle or one with a load space separated from the cab; ordinary cars are not recommended,
• if you do use a car, the cylinder goes in the boot, never on a seat, with the windows open and the ventilation on,
• valve closed, regulator and hoses removed, cap fitted,
• the cylinder secured so that it cannot shift when you brake or corner,
• no smoking, a fire extinguisher in the vehicle, straight to your destination and unload as soon as you arrive,
• never leave cylinders in a parked, unventilated vehicle.

Messer’s guide gives as a rough limit that a car can carry at most 4 cylinders of up to 12 l, and does not recommend carrying cylinders from 12 to 50 l that way. A 20 l cylinder already falls into the second group, so for larger cylinders consider delivery by your gas supplier.

Valve, regulator and cap

The valve is the most delicate part of the cylinder. Open it slowly to avoid a pressure surge. If a valve is hard to open, do not force it: stop using the cylinder and contact your gas supplier. Never repair a valve yourself; report any damage to your gas supplier. Do not rely on the regulator to shut off the gas; the cylinder valve does that. Before transport, always remove the regulator, even with the valve closed, and fit the cap.

Gas cylinders are subject to periodic inspection and testing. The rules and intervals depend on the country. If you rent the cylinder, ask your gas supplier who looks after testing. If you own it, check the date of the next test on the cylinder and ask your gas supplier or local authority which rules apply.

Cylinder size, dimensions and weight

The weight and height of a cylinder decide whether you can lift it on your own and whether it fits on a cart. Typical figures for steel cylinders from one supplier:

Cylinder weights can vary by ±5%. A large 50 l cylinder is more than 1.6 m (5 ft 3 in) tall and weighs 68–84 kg, and over 110 kg (243 lb) when filled with CO2, so loading it needs a second person or lifting equipment. The 20 l and 8/10 l cylinders that our welding cart S is designed for are much lighter and shorter.

When you need a cylinder cart

The rules do not tell you to buy a cart as such, but the cylinder must stand upright and be secured against falling over, and the safety data sheets recommend a trolley whenever a cylinder is moved. If you always weld in the same place, a solid wall bracket is enough. If your welding station moves around, a cart is the simplest way to meet both requirements at once.

Size S is designed for one 20 l or 8/10 l cylinder beside a welder of up to 30 kg (66 lb). For 50 l cylinders and for two gases we are preparing sizes L and XL, which are coming soon. How to match a cart to your welder and cylinder is covered in our guide on how to choose a welding cart, and which gas to choose in the guide on shielding gas for MIG and TIG.