An annual inspection of safety devices is recommended. Testing requirements will be based on the type of device and a quantified risk analysis. Typical replacement or function testing of relief valves is between 5 and 10 years depending on the application within the industrial gas industry. Rupture discs are not tested but are frequently replaced on an interval based on manufacturer…
Based on the question, it’s not clear if the reference to stress corrosion cracking (SCC) has been proven or is only suspected. It can be difficult to identify the nature of the cracks (SCC vs H2 embrittlement without analysis and microscopy). In addition, the question does not mention that the cylinders contain hydrogen gas, but it’s assumed since it was submitted to the Panel.
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It depends on the service. Variables include disk design, corrosion resistance, number of cycles, and how to close the operating pressure is to the rupture disc set pressure. One approach is to ask the manufacturer for their recommendation. Typical practice for U.S. Department of Transportation vessels and discs is to replace them at the tube requalification (i.e., every 5 to 10 years in the U…
The answer could be no devices at all, just a TPRD, just a PRD, or both. It depends on the potential overpressure scenarios identified during a hazard assessment. TPRDs typically are not used on ASME pressure vessels since they are not ASME compliant devices and since system siting provides protection from engulfing fires. However, TPRDs are frequently used in portable applications for…
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.
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…
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…
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.…
Equation 6.3.1.1 in CGA S1.3 is based on modeling to API methods described in: Heitner, T. Trautmauis, and M. Morrissey, “Relieving Requirements for Gas Filled Vessels Exposed to Fire,” 1983 Proceedings-Refining Department, Volume 62, American Petroleum Institute, Washington, D.C., pp. 112-122.
This method considers the transient nature of the vessel warming in combination with the…
API 520, Sizing, Selection, and Installation of Pressure-relieving Devices Part I - Sizing and Selection, was written for use in the process industries in gas and liquid service.
CGA S1.3, Pressure Relief Device Standards-Part 3-Stationary Storage Containers for Compressed Gases was written for fixed equipment in gas service.
Which standard to use depends on the choice by the owner…
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