LTL TATM LTL - Vol 1
Issue 1.0
26
combustion. There is a risk of asphyxiation in high concentrations and under no circumstances must
it be inhaled.
To be of any practical use, cylinders need to contain a significant quantity of gas compressed to as
high a pressure as possible. By simple laws of physics, the higher the pressure, the smaller the
volume occupied by the gas, hence the smaller and more
manageable the cylinder can be made.
There is a great deal of stored energy inside the thick walls of the gas cylinder. Energy that can be
useful to the user, but needs to be controlled to prevent it from causing harm. In particular, gases
released from a cylinder, whether by controlled opening of the valve, or due to a leak, can have a very
high velocity. It is possible that dust particles, or debris from the working area, may become entrained
in the gas flow and cause injury to the eyes, face or other parts of the body.
The volume of the gas stored under pressure within a cylinder will occupy much larger volumes when
expanded to atmospheric pressure. It is important to realise the potential this volume of gas might
have for displacing breathable air at the work place. The majority of gas companies fill cylinders to
200-300 bar. The gas contained in a 50 litre cylinder, when compressed to 200 bar will fill a space
8.5m
3
in volume if it is released to atmosphere.
Gas under pressure in a small volume expands very rapidly to a lower pressure. It takes heat energy
from the surroundings. It can lead to serious problems to the unwary user, since the heat drawn from
the metal in valves and regulators can cause them to freeze and frost up. If these metal parts are
touched they can cause frostbite or cold burns which are very painful and difficult to treat. It is
advisable to wear gloves when dealing with helium cylinders. This sort of situation can occur if a valve
is left cracked open or a valve failure develops.
6.2.1 Storage of Cylinders
When the helium top up cylinders are delivered, they will usually be single cylinders as opposed to the
way the helium arrives for the inflation. Sometimes however, the helium will be delivered as a titan
(ie. 16 cylinders together).
These will be left on site until they are used and are ready for return. Whilst the cylinders are on site,
they should be stored on a flat, level, solid and well-drained surface. The storage area should be
secure to prevent unauthorised access. It should be segregated from car parks and areas where
people congregate.
Wherever possible the storage should be outside in the open air where leaks will dissipate quickly. If
it is necessary to store the cylinders indoors, then there should be adequate low and high level
ventilation. Measures should be taken to ensure that the cylinders do not fall over or are not knocked
over. If the cylinders have to be stored against a building, then avoid proximity to doors and gangways
and also windows and other openings above the cylinders. Good housekeeping is important.
Separate full cylinders from empty, and avoid the accumulation of rubbish etc., especially combustible
materials.
6.2.2 Handling Cylinders
Wherever possible, cylinders should be moved using a purpose designed cylinder trolley, particularly
on uneven ground and by inexperienced operators. If a trolley is not available, then cylinders can be
churned short distances, one at a time, with one hand steadying the cylinder at the valve guard, and
the other hand rotating the body of the cylinder. Always check that the valve guard is securely
attached before moving a cylinder. When handling cylinders, suitable gloves and protective footwear
should always be worn. When cylinders are being connected or disconnected, eye protection should
be worn.