Safely Using Hydrogen In Laboratories

Weldstar supplies a large selection of hydrogen to Northern Illinois, along with various other specialty gases. Weldstar quite often supplies hydrogen and other specialty gases to research laboratories and various other industries, so we felt it would be helpful for our Northern Illinois customers to be knowledgable on the safe use of hydrogen in laboratories.

With escalating costs associated with the limited helium supply, those tasked with operating and designing laboratory equipment are progressively 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 understand the risks that conincide with the storage, distribution, and use of hydrogen along with the fire and safety code regulations controlled 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 altered the Maximum Allowable Quantities (MAQ) specifically established for hydrogen. These MAQ’s are distinguished for each storage area, determined by storage in either an unsprinklered or completely sprinklered building and restricted further based on the hydrogen cylinders being contained in gas cabinets or not. The corresponding volumes are expressed as standard cubic feet (cuft) of hydrogen at 1 atmosphere of pressure. In an unsprinklered building where not all cylinders are stored in gas cabinets, the MAQ is restricted to 1,000 cuft, whereas that quantity is doubled to 2,000 cuft if all cylinders are stored in gas cabinets. Likewise, for sprinklered buildings 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 defines limitations determined by hydrogen use in control areas or using 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 primary areas and necessities for hydrogen installation when referring to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA explains that for flammable gases kept or utilized in quantities larger than 250 cubic feet, a 1-hour fire resistance rated constrction shall be used to separate the area. The compressed gas cylinders must be separated by 10’ or a nonflammable wall; yet, they must be separated by 20’ or a nonflammable wall containing a minimum fire resistance rating of .5 hours from incompatible materials like oxygen. For areas with hydrogen systems, appropriate safety placards must likewise be permanently set up.

Likewise, Section 6.16 details that indoor storage and use areas must be given either natural or mechanical ventilation, so long as the natural ventilation is verified to be adequate for the gas employed. If being ventilated mechanically, the system must function 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 assure proper exhaust ventilation. Part III of this series will detail the remaining NFPA 55 requirements for separation and controls.

To further explain the series discussing updates to NFPA 55 regulating the proper utilization of hydrogen in laboratories, we will elaborate on our discussion selectively explaining some of the important areas and requirements for hydrogen installation in reference to separation and controls.Section 7.1.6.2 of NFPA 55 dictates 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 distance can be limitlessly decreased when separated by a barrier constructed 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 requirement for compliance. Section 414.4 of the IBC demands that controls must be good enough 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 consequence 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 above 10,000°F.Aside from piping requirements, these codes also require the utilization 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 governing the the proper use of hydrogen in labs, we will conclude our discussion by describing applications where the Maximum Allowable Quantities (MAQ’s) is less than the demand for hydrogen gas cylinders.

It is quite typical to come across installations in which the need for hydrogen is bigger than the MAQ’s, most often in instrumentation uses and/or chemical reactions like hydrogenation. These are frequently come across 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 combined with the IBC and IFC requirements will allow for these volumes exist within a building; however, certain building improvements are called for, effectively requiring that the facility constructs a hydrogen shelter. These upgrades are comprised of enhancements to the structure fire rating, transportation, fire detection, a occupant limit, and a restraint on the amount of stories of the building. Not only this, but these installations likewise have strict requirements in regards to distancing along with floor and wall ratings. Although feasible, this scenario is not ideal and should be avoided if possible. A more effective solution would be to group the facility’s requirements into several, smaller systems in which the compressed gas cylinders may be inserted completely in gas cabinets.

Weldstar is a trusted132] supplier of hydrogen, along with various other specialty gases and specialty gas equipment to the Northern Illinois area. Whether you need specialty gases for use in your laboratory research, or any other industry in Northern Illinois, Weldstar will have the products you need to get the job done. To find out more about Weldstar and our specialty gas products in Northern Illinois, browse our website and catalog. We can be reached at 855-998-4875 or via email at starrant@weldstar.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016