Purchasing Hydrogen - Thermo Scientific TRACE 1600 Hardware Manual

Purchasing Hydrogen

Thermo Scientific
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.
The lower flammable limit of hydrogen in air is 4%.
Vent the oxygen exhausted by the electrolyzer to the outside as well.
IMPORTANT Use a hydrogen generator that uses a palladium dryer or a
proton-exchange membrane to create hydrogen gas from deionized water.
Use pressure swing adsorption and molecular sieve technology to remove moisture
content down to trace levels.
Hydrogen Safety Precautions
TRACE 1600/1610 Hardware Manual
Preface
xxvii