The containerized electrolysis unit should be installed per manufacturer instructions, the requirements
of its listing such as to ISO 22734, Hydrogen generators using water electrolysis - Industrial, commercial,
and residential applications, and NFPA 2, Hydrogen Technologies Code. A primary consideration for
indoor installation is the potential for hydrogen releases from the system,…

The suspected cause was a mixture of oxygen and hydrogen that passed downstream from the electrolysis unit into several storage vessels. Hydrogen-oxygen mixtures are very hazardous. Subsequent ignition resulted in internal pressure that exceeded the limits of the storage system. The design of electrolyzers, detection of upset conditions, and preventing the accumulation of oxygen within the…

Nitrogen/helium blends are frequently used to leak test hydrogen systems.

Speed of detection, detection limit, location, and cross-sensitivity are some of many criteria that might be used for selecting a detector. A common setpoint for gaseous hydrogen detection is 25% of LFL, or 1% concentration in air. However, the detection limit also depends on the system and exposure. When specific hazards are likely, detectors may have detection limits in the low-ppm range.…

Leak detection system requirements depend on the system design and applicable codes. The
appropriateness of detection equipment depend on many factors, including the type of system,
application, location, and probability of leaks. For example, hydrogen refueling stations are required by
code to be equipped with leak detection systems.

While hydrogen gas detectors are less effective outdoors, they can be an important safeguard as part of an overall hydrogen system design. They have been used in many cases to automatically shut down equipment and isolate hydrogen supply. Location and type of detectors depend on the system design and siting, but when installed, should be in areas that are most likely to be exposed to hydrogen…

Training personnel and equipping them with portable gas detectors to properly identify the gas that is
leaking can play an important role in both troubleshooting and emergency response.

The manufacturer’s calibration requirements should be followed to ensure proper operation of the
detection system. The requirements will vary depending on the type of detector and the environment in
which they are installed. Calibration can usually be performed by the user/owner if properly trained and
supplied with calibration gas, etc.

There is no maximum flow-rate that can be vented to the atmosphere, but the hazard analysis should consider the potential risk of dispersion, radiation, and overpressure as part of the vent system design. Flare systems are often used at large hydrogen production facilities as one means to prevent a large unignited cloud from forming but will depend on the specific application.

The routing will be dependent on the system design, size of release, and evaluation of the hazards.
Smaller systems are rarely vented to a flare due to complexity, availability and permitting considerations.
Facilities handling large amounts of hydrogen such as production plants will often have a flare system
since they have more capability for this additional onsite infrastructure.…