Safely Using Hydrogen In Laboratories

Delille Oxygen Company offers a large selection of hydrogen to Columbus, along with many other specialty gases. Delille Oxygen Company quite often supplies hydrogen and other specialty gases to research laboratories and various other industries, so we felt it would be helpful for our Columbus customers to be up to date on the safe use of hydrogen in laboratories.

With escalating costs correlated with the limited helium supply, those who operate and design laboratory equipment are increasingly turning to their gas suppliers for hydrogen.  Hydrogen is used in a wide array of facilities from analytical laboratories to universities, medical research facilities, and chemical process buildlings.  Still, it is extremely important to comprehend the risks that conincide with the storage, distribution, and use of hydrogen along with the fire and safety code rules created 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 redefined the Maximum Allowable Quantities (MAQ) expressly created for hydrogen. These MAQ’s are discerned for each storage area, decided by storage in either an unsprinklered or completely sprinklered building and restricted further 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 which some cylinders are not stored in gas cabinets, the MAQ is restricted to 1,000 cuft, whereas that quantity is increased to 2,000 cuft if all cylinders are stored in gas cabinets. Also, for sprinklered buildings that do not have all cylinders stored in gas cabinets, the MAQ is also 2,000 cuft. That volume is doubled to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further states limitations determined by hydrogen use in control areas or using outside storage, part II of this series will detail the infrastructure needs for compliance.

We will further our discussion by selectively describing some of the primary areas and necessities for hydrogen installation in regards to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA states that for flammable gases kept or utilized in quantities larger than 250 cubic feet, a 1-hour fire resistance rated constrction will be utilized to separate the area. The compressed gas cylinders should be separated by 10’ or a noncombustible wall; however, they need to be separated by 20’ or a nonflammable wall that contains a minimum fire resistance rating of .5 hours from incompatible elements like oxygen. For locations having hydrogen systems, proper safety signs must also be permanently affixed.

Additionally, Section 6.16 states that use and storage areas that are indoors must be given either natural or mechanical ventilation, so long as the natural ventilation has proved to be sufficient for the gas utilized. 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 account for gas density to guarantee sufficient exhaust ventilation. Part III of this series will expand on the remaining NFPA 55 requirements for separation and controls.

To further explain the series discussing updates to NFPA 55 ensuring the safe employment of hydrogen in laboratories, we will continue our discussion selectively addressing some of the important areas and requirements for hydrogen installation in terms of 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 states that this space can be limitlessly reduced 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 declared 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 work without fail. Section 2703.2.2.1 of the IFC demands suitable materials for hazardous media, the main negative result being that 316L SS or copper piping shall be employed 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 greater than 10,000°F.Aside from piping requirements, these codes also demand 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 last section in the NFPA 55 series governing the the proper use of hydrogen in labs, we will finish our analysis by describing applications where the Maximum Allowable Quantities (MAQ’s) is less than the demand for hydrogen gas cylinders.

It is not unusual to find installations where the demand for hydrogen is larger than the MAQ’s, usually in instrumentation uses and/or chemical reactions like hydrogenation. These are often encountered in installations using hydrogen where there is no outside storage and control to line pressures lower than 150 PSIG is unobtainable . The NFPA 55 code and the IBC and IFC requirements make it possible for these volumes exist within a building; however, significant upgrades to the building are needed, effectively dictating that the facility build a hydrogen shelter. These upgrades consist of advancements to the structure fire rating, transportation, fire detection, a occupant limit, and a building story limit. Not only this, but these installations likewise have strict requirements in regards to distancing along with floor and wall ratings. Although doable, it is best to avoid this scenario seeing as it is not optimal. A better answer would be to combine the facility’s requirements into many, smaller systems in which the compressed gas cylinders can be installed entirely in gas cabinets.

Delille Oxygen Company is a dependable132] provider of hydrogen, along with various other specialty gases and specialty gas equipment to the Columbus area. Whether you are in search of specialty gases for use in your laboratory research, or any other industry in Columbus, Delille Oxygen Company will have the products you need to carry our your operations. To find out more about Delille Oxygen Company and our specialty gas products in Columbus, browse our website and catalog. We can be reached at (614) 444-1177 or via email at scotta@delille.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016