FAQ Categories: Miscellaneous
Precautions applicable to oxy-acetylene torches are likely applicable here and are a good starting point. Recommendations for the hardware are best provided by the cylinder supplier, and all these…
There is no standard which specifically specifies the use of a flapper. A properly designed flapper should provide de minimus restriction to vent flow, yet still provides weather protection which…
Yes, the pressure safety relief system on LH2 tanks is sized for the loss of vacuum condition. The spring-loaded safety valves are sized for lower demand cases such as runaway pressure build or…
There is no specific requirement not to vent liquid hydrogen from a vent system. Best practice would be to only vent gas from the top of the vessel to relieve pressure. If liquid must be vented,…
LNG storage, plumbing, and other systems can’t be directly retrofitted to handle hydrogen. The LNG components and systems will need to be removed and replaced with equipment specifically designed…
Example safety guidelines are listed below but may not be all-inclusive (e.g., they do not cover general practices such as lockout/tagout, management of change, job safety analysis), and most are…
Purging can be accomplished in several ways including by using pressure cycles, sweeping, or vacuum. Sweeping is the least reliable but can be effective on simple pipe runs. In most cases, vent…
- Understand any reactions the hydrogen can add to what is being vented. For instance, O2/H2 vented in the same stack would not be a good idea.
- Understand all the flow and operating…
There is no generalized exception for hydrogen fueling stations. However, PSM is intended for employee protection. It’s not intended for retail operations or customers. Through paragraph…
Purging is not recommended as a continuous part of vent stack operation. However, maintenance activity is a transient event and it’s prudent and recommended to purge a vent system prior to…
It depends on the construction and location of the lights. Assuming the typical practice of using non-classified lighting on vehicles, operation of those lights during a delivery could provide an…
The HSP discourages the use of this type of piping for hydrogen despite the low likelihood of ignition within the pipe itself. The polyethylene film can indeed develop a charge and, depending on…
We are not aware of a study for blended NG/H2. However, for high concentrations of NG, the vent system should be similar to NG, which still recommends a vent system as NG is less dense than air.…
Liquid hydrogen is rarely vented as a liquid. If liquid hydrogen is vented, there should be a means to ensure that it is fully vaporized. The vent systems for LH2 tanks are connected to the vapor…
In the U.S., there is no specific national requirement for fuel cell test equipment to be certified. There may be requirements from the local authority having jurisdiction (AHJ). Local building…
Because a small spark can ignite hydrogen-air mixtures, precautions such as using spark-resistant tools is one method that can be considered to reduce the probability of an ignition. However,…
We would not open the vent system to inspect the internal piping without a good reason.
It is recommended to check for water in the vent stack trap
- At startup and daily during…
I am not sure which picture you are referring to so I will attempt to answer.
If you are referring to the incident where a fire occurred and the vent system was damaged, then this may have…