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We have an onsite Emergency Response Team with a substantial amount of Liquid Hydrogen but haven't found ERT-specific training for handling Liquid Hydrogen Fires. Are you aware of any existing training?

AICHE ELA253 CHS ” Introduction to Hydrogen Safety for First Responders” is a good reference and discusses both LH2 and GH2. LH2 fires are very unusual. LH2 releases usually are GH2 so the fires at either ambient for low flow or the GH2 is a cryo temperature for high flow. Fires from LH2 tanks ignite less frequently than GH2 high-velocity releases. The colder the gas the less potential for…

Category: Hazards Analysis
Keywords: First Responders, Safety, LH2, GH2, Guidelines, Fire Protection
Which ASME B31 piping code should be used for repair and alteration of hydrogen piping systems?

The code used for repair and alterations of an existing system depends on the code used for construction as well as on the requirements imposed by the jurisdiction. Note that getting a permit from the jurisdiction may be necessary for an extensive alteration.

Code of ConstructionGenerally Accepted Code for Repair and Alterations…
Category: Piping
Keywords: Piping, Codes
Which ASME B31 piping code should be used for changing the rating of hydrogen piping systems?

The requirements of the code used for the original construction apply. The piping may meet the requirements of more than one code. In which case, the code used for changing the rating may be different than the original code of construction. In any case, the re-rated system should meet all of the requirements of the selected code. Note that if the original proof test of the system was…

Category: Piping
Keywords: Codes, Piping, Requirements
Which ASME B31 Code should be used for the construction of hydrogen piping systems?

At least three of the ASME B31 piping codes are logical choices:

  • ASME B31.1, Power Piping
  • ASME B31.3, Process Piping
  • ASME B31.12 Hydrogen Piping and Pipelines

Considerations for code selection include:

  • Requirements imposed by the authority having jurisdiction, whether by direct reference or…
Category: Piping
Keywords: Piping, Codes, Requirements
The local AHJ has asked if any part of the system piping will be routed below ground and has requested details on required corrosion protection system, trenching, and backfill. They cite the following sections of NFPA2: 7.1.15.3.2 Contact with Earth. 7.1.15.3.2.1 Gas piping in contact with earth or other material that could corrode the piping shall be protected against corrosion in an approved manner. "55:7.1.17.2" 7.1.15.3.2.2 When cathodic protection is provided, it shall be in accordance with 7.1.18. "55:7.1.17.2.1" 7.1.15.3.3 Underground piping shall be installed on at least 6 in. (150 mm) of well-compacted bedding material. "30:27.6.5.1" 7.1.15.3.4 In areas subject to vehicle traffic, the pipe trench shall be deep enough to permit a cover of at least 18 in. (450 mm) of well-compacted backfill material and pavement. "30:27.6.5.2" 7.1.15.3.5 In paved areas where a minimum 2 in. (50 mm) of asphalt is used, backfill between the pipe and the asphalt shall be permitted to be reduced to 8 in. (200 mm) minimum. "30:27.6.5.3" The instrument, air and hydrogen lines are stainless steel and will be installed in a PVC sleeve. In the Panel’s experience, is this adequate cathodic protection for the lines?

The Panel considers two approaches to be acceptable. 

  1. Stainless steel (corrosion resistant) lines embedded in concrete. This keeps the piping out of direct contact with the earth and provides a degree of physical protection from activities such as digging. 
  2. Lines enclosed within a PVC sleeve. The PVC sleeve would usually be directly buried but could also be…
Category: Piping
Keywords: Piping, Underground, Corrosion, Physical Protection
Can compression fittings for 304 or 316 SS tubing that use compressive forces to swage the fitting on onto tubing be used? The fitting is made for up to three pieces. One concern is the potential for hydrogen embrittlement in the area around the joint compression as the pipe is under large stresses when the joint is made. There is a video on how this works at the link below, starting at ~ 2 min 20 secs. (437) The Lokring High Performance Connector System - YouTube

The HSP is not familiar with this particular fitting or its potential application in H2 service but can offer engineering judgment. Many similar compression-type swaged fittings are used in H2 service. These fittings must be used within the manufacturer recommendations for pressure, temperature, and fluid service. Deformation is also introduced into stainless steel tubing in other ways, such…

Category: Piping
Keywords: Piping, Fitting, Lokring Technology, Material Selection
What safety standards apply to liquefied hydrogen vacuum-insulated pipes? What are the maintenance and inspection considerations?

The primary safety standards for applicable to this piping in the U.S. are ASME B31.3, B31.12, and NFPA 2. The editions used should be those adopted by the local jurisdiction. Design of an LH2 piping system should always be conducted and reviewed by engineers experienced in cryogenic piping design. The equipment should also be installed per NFPA 2 and NFPA 55. IT is recommended that the piping…

Category: Piping
Keywords: Piping, Liquid, Safety, Vacuum, Insulated, Standards
When generating hydrogen in a high-pressure catalytic reactor, what type of material should be used to prevent H2 embrittlement or corrosion?
…
Category: Piping
Keywords: Piping, Pressure, Corrosion, Embrittlement
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This material was prepared as an account of work sponsored by an agency of the United States Government.
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The portal brings together and enhances the utility of a variety of tools and web-based content on the safety aspects of hydrogen and fuel cell technologies to help inform those tasked with designing, approving or using systems and facilities, as well as those responding to incidents.

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