The Panel recommends performing a pressure test at 110% of design pressure. This requirement should be applied to all systems regardless of construction type since the intent is to ensure pressure integrity and proper installation. All fitting types have modes of failure during installation. For example, there are numerous examples where compression fittings have had ferrules installed…
The HSP recommends against the use of glycols for pressure tests due to the difficulty of adequately removing all glycol that might be left in a system after a hydrotest. The HSP recommends a pneumatic test at 110% of the system maximum allowable working pressure (MAWP), which is acceptable by code. Due to an increased danger with pneumatics vs hydrotesting, establish a pressure test zone for…
The answer will depend on if it is only H2 measured or if VOCs are also included. The type of gas sensor may change since many detectors are limited to flammable gases. To provide feedback, the Panel would require more details on the sensors being used on the project and the failure modes. There are concerns about allowing hydrogen concentrations as large as 3.5% for the high level alarm.…
There are many manufacturers of multiple types of flame detectors and it’s best to seek their input for the advantages of different types for specific applications. Regarding flame detector technology, UV detectors have been prone to false alarms from outside sources such as sunlight, lightning, and welding/cutting torches. The newer triple-IR detectors that are specifically designed and…
One pertinent reference is a Sandia National Laboratories paper by Schefer et al: Spatial and radiative properties of an open-flame hydrogen plume, Intl J. Hydrogen Energy, 31 (2006): 1332-1340. Information on this and other similar papers are available at https://h2tools.org/bibliography. Further information can probably be obtained from the author of this paper and other papers reporting…
The Panel is not aware of any standard for hydrogen detectors for onboard vehicle applications. Some information is available in the SAE Technical Information Report: TIR J3089 Characterization of On-Board Vehicular Hydrogen Sensors, which was published in 2018.
Hydrogen affects the mechanical properties of most materials. For example, hydrogen reduces the
fracture toughness and increases the fatigue crack growth rate in steels. There is a significant amount of
research, analytical work, and codes and standards development being undertaken to improve our
understanding of how these materials can be utilized in pipelines. The results of the…
Because cast irons are relatively brittle materials, they should generally be avoided in industrial and
transmission pipeline applications. In low pressure applications like residential distribution piping
systems, the use of cast irons is probably acceptable.
Acceptability of materials is highly dependent on the specific application. Applied stress levels, exposure to contaminants, the operating temperature, the partial pressure, and number and magnitude of material stress cycles are some of the factors that affect material selection. Guidance is provided within documents such as ISO 11114, Gas cylinders - Compatibility of cylinder and valve…
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.
We are the leaders in the building industries and factories. We're word wide. We never give up on the challenges.