Safely Using Hydrogen In Laboratories

Coastal Welding Supply supplies a large selection of hydrogen to Beaumont, along with several other specialty gases. Coastal Welding Supply quite often supplies hydrogen and other specialty gases to research laboratories and various other industries, so we felt it would be useful for our Beaumont customers to be knowledgable on the safe use of hydrogen in laboratories.

With escalating costs correlated with the limited volume of available helium, those who operate and design laboratory equipment are progressively turning to their gas suppliers for hydrogen.  The use of hydrogen is found in several facilities, from medical research facilities to universities, analytical laboratories, and chemical process buildings.  However, it is crucial to be aware of the risks that hydrogen storage, distribution, and use present along with the fire and safety code requirements governed by the National Fire Protection Association’s Compressed Gases and Cryogenic Fluids Code (NFPA 55) and the International Fire Code (IFC) and International Building Code (IBC).

Recent updates to NFPA 55 have changed the Maximum Allowable Quantities (MAQ) expressly created for hydrogen. These MAQ’s are distinguished for each storage area, affected by storage in either an unsprinklered or completely sprinklered building and further limited based on whether or not the hydrogen cylinders are being contained in gas cabinets. The corresponding volumes are expressed as standard cubic feet (cuft) of hydrogen at 1 atmosphere of pressure. In an unsprinklered building in cylinders are stored in additional areas rather than simply gas cabinets, the MAQ is bounded to 1,000 cuft, whereas that quantity is multiplied to 2,000 cuft if all cylinders are stored in gas cabinets. Likewise, for sprinklered rooms where not all cylinders are stored in gas cabinets, the MAQ is also 2,000 cuft. That amount is multiplied to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further states limitations defined by hydrogen use in control areas or employing outside storage, part II of this series will discuss the infrastructure needs for compliance.

We will further our discussion by selectively describing some of the main areas and needs for hydrogen installation when referring to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA states that for flammable gases kept or used in greater quanities than 250 cubic feet, a 1-hour fire resistance rated constrction will be utilized to separate the area. The compressed gas cylinders require separation by 10’ or a noncombustible wall; but, they require separation by 20’ or a nonflammable wall containing a minimum fire resistance rating of .5 hours from incompatible materials like oxygen. For areas that have hydrogen systems, appropriate safety placards must also be permanently affixed.

In Addition, Section 6.16 declares that use and storage areas that are indoors must be provided with ventilation, either mechanical or natural, so long as the natural ventilation is proven to be acceptable for the gas used. If using a mechanical ventilation process, the system must be operational while the building is occupied, with the rate of ventilation being at a minimum of 1 ft3/min per square foot of floor area of storage/use and being armed with an emergency power system for alarms, vents, and gas detection. The system must also keep track of gas density to assure proper exhaust ventilation. Part III of this series will discuss the rest of the NFPA 55 requirements for separation and controls.

To continue the series that explains updates to NFPA 55 governing the safe use of hydrogen in laboratories, we will further our discussion selectively explaining some of the main areas and requirements for hydrogen installation in reference to separation and controls.Section 7.1.6.2 of NFPA 55 explains that any flammable or oxidizing gases need to be separated by 20’ from each other, while section 7.1.6.2.1 declares that this space can be limitlessly decreased when separated by a barrier comprised of noncombustible material a minimum of 5’ tall that provides a fire resistance rating of at least .5 hours.

The safe use of controls in hydrogen systems are stated by NFPA 55, IFC, & IBC, creating a slightly more nuanced neccessity for compliance. Section 414.4 of the IBC demands that controls must be sufficient for the intended application, with automatic controls being required to operate fail-safe. Section 2703.2.2.1 of the IFC calls for suitable materials for hazardous media, the main consequence being that 316L SS or copper piping shall be used and identified in accordance with ASME A13.1 with directional arrows every 20’. The system should also contain no concealed valves or breakable connections, using welded or copper brazed joints where the piping is concealed. NFPA 55 requires that these brazing materials should have a melting point above 10,000°F.Aside from piping requirements, these codes also call for the use of emergency shutoff valves on supply piping at the point of use and source of compressed gas, along with backflow prevention and flashback arrestors at the point of use.

As the final installment in the NFPA 55 series about the safe use of hydrogen in laboratories, we will close our explanation by explaining uses where the need for hydrogen gas cylinders is higher than the Maximum Allowable Quantities (MAQ’s).

It is quite typical to find installations where the demand for hydrogen is larger than the MAQ’s, most often in instrumentation uses and/or chemical reactions like hydrogenation. These are commonly found in installations using hydrogen where outside storage is unavailable and control to line pressures of less than 150 PSIG is unobtainable . The NFPA 55 code combined with the IBC and IFC requirements allows these volumes be in a building; however, significant upgrades to the building are needed, effectively demanding that the facility build a hydrogen shelter. The upgrades include improvements to the structure fire rating, transportation, fire detection, a limitation on the number of occupants, and a limit to the number of stories a building can have. Additionally, these instillations have stringent distancing regulations as well as floor and wall ratings. Although feasible, this scenario is not ideal and should be avoided if possible. A better answer would be to group the facility’s requirements into numerous, smaller systems where the compressed gas cylinders may be set up exclusively in gas cabinets.

Coastal Welding Supply is a trusted132] supplier of hydrogen, along with several other specialty gases and specialty gas equipment to the Beaumont area. Whether you need specialty gases for use in your laboratory research, or any other industry in Beaumont, Coastal Welding Supply will have the products you need to complete your tasks. To find out more about Coastal Welding Supply and our specialty gas products in Beaumont, browse our website and catalog. We can be reached at 800-852-4177 or via email at jcmazoch@coastalws.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016