FAQ Keywords: Temperature
Relief device sizing for liquid hydrogen tanks follow recognized standards such as CGA S1.3. The sizing criteria include a worst-case scenario of an engulfing fire with loss of vacuum integrity.…
H2-air flammability limits vary with temperature . The H2-air lower flammability limit is virtually the same as the H2-O2 lower limit. However, the H2-O2 upper flammability limit increases…
The vent system should be designed for the temperature at which it operates (ambient for GH2 and Cryogenic for LH2). The outlet of the vent system should be designed for a fire to ensure the…
CGA G-5.5 provides several options for vent stack outlets but not all options, nor does it tell when one outlet type is better than another design.
Figure 7, is one design, but in my opinion…
Heat tracing can be used as a safeguard against freezing. However, it must be understood that:
- The heat trace system uses a utility supply so may not always be operational. …
This is a fairly common arrangement and can be acceptable if properly designed. Some considerations:
- The main concern is low temperature downstream of the mixing point, in case of…
Plugging is a concern before, during, and after a release. Prior to the release, water may accumulate in the vent system from weather conditions (rain, snow, etc.) or from condensation,…
In laboratories, 316 stainless steel tubing is frequently the first choice for small flow and pressures less than 2800 psi (19 MPa). See…
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…
There are no differences in the process design of the vent stack since the venting requirements will follow the same sizing and pressure rating requirements regardless of vent configuration.…
Water icing at the exit of a stack is certainly an issue in cold climates. Significant effort has been put into vent stack outlet design to minimize the probability. Documents such as CGA G5.5…