Purchasing Hydrogen - Thermo Scientific TRACE 1300 Instruction Manual

Preface
Hydrogen Safety Precautions

Purchasing Hydrogen

xxii TRACE 1310 Auxiliary Oven Instruction Manual
Manual shutoff valves should be provided near each point of use, within immediate reach.
If a hydrogen cylinder or hydrogen generation system is located within immediate reach,
a separate point-of-use shutoff valve is usually not necessary.
Line regulators that have their source away from the point of use should have a manual
shutoff valve near the point of use.
An emergency gas shutoff device in an accessible location outside the use area should be
provided in addition to the manual point-of-use valve in each educational and
instructional laboratory space that has a piped gas supply system.
If necessary, the piping system should have uninterruptible pressure relief. The pressure
relief system should be designed to provide a discharge rate sufficient to avoid further
pressure increase and should vent to a safe location outside or to a ventilation system
exhaust.
Use the following guidelines when purchasing hydrogen:
• Hydrogen Generator—Because it minimizes the amount of hydrogen present and reduces
the degree of hazard, a hydrogen generator (also called an electrolyzer) is the safest way to
purchase hydrogen in the quantity used in gas chromatography/mass spectroscopy
systems.
However, to minimize the degree of hazard, operate the hydrogen generator only in a
non-explosive environment because hydrogen buildup can be ignitable. Thus, your
ventilation system for the room or lab hood where the hydrogen generator operates must
maintain an air exchange rate at least two orders of magnitude greater than the maximum
hydrogen production rate of the hydrogen generator. Follow the manufacturers'
directions about proper use and maintenance of the regulator.
To prevent the possibility of releasing hydrogen, set the hydrogen generator to shut down
if:
−
There is a loss of flow to the ventilation system
−
A hydrogen detector alarms at 25% of the lower flammable limit of hydrogen in air.
Vent the oxygen exhausted by the electrolyzer to the outside as well.
• Hydrogen Cylinder—Hydrogen can be delivered in standard laboratory gas bottles or
cylinders. These cylinders have a limited amount of hydrogen in them and are a safe way
to transport and store hydrogen. Always secure, compressed hydrogen gas cylinders, like
all compressed gas cylinders, in an upright position, ideally with a non-combustible chain
or cable. If the cylinder falls over, the valve can fall off, causing the pressurized cylinder to
take off like a rocket, leading to the release of hydrogen and possibly an explosion, severe
injury, or death. Never crack a hydrogen cylinder valve to remove dust or dirt from
fittings prior to attaching a regulator, as there is a risk of self-ignition.
Thermo Scientific