Safely Using Hydrogen In Laboratories

Fresno Oxygen & Welding Supplies/Barnes Welding Supply supplies a large selection of hydrogen to Fresno, along with various other specialty gases. Fresno Oxygen & Welding Supplies/Barnes 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 Fresno customers to be updated on the safe use of hydrogen in laboratories.

With escalating costs associated with the limited amount of helium that is available, those tasked with operating and designing laboratory equipment are beginning to turn more frequently 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.  Nonetheless, it is extremely important to comprehend the risks that are posed through the use, distribution, and storage of hydrogen along with the fire and safety code rules directed 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) spelled out specifically for hydrogen. These MAQ’s are discerned for each storage area, determined by storage in either an unsprinklered or completely sprinklered building and limited additionally based on whether the hydrogen cylinders are contained in gas cabinets or other locations. 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 number 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 number is increased to 4,000 cuft if all cylinders are stored in gas cabinets. NFPA further defines limitations defined by hydrogen use in control areas or using outside storage, part II of this series will explain the infrastructure requirements for compliance.

We will elaborate on our discussion by selectively describing some of the main areas and requirements for hydrogen installation in regards to fire-resistance rating and ventilation.Section 6.3.1.3.1 of NFPA states that for flammable gases saved or used in amounts greater than 250 cubic feet, a 1-hour fire resistance rated constrction shall be used to separate the area. The compressed gas cylinders require separation by 10’ or a nonflammable wall; yet, they need to be separated by 20’ or a fire-resistant wall having a minimum fire resistance rating of .5 hours from incompatible matters like oxygen. For locations containing hydrogen systems, necessary safety notices must also be permanently affixed.

In Addition, Section 6.16 details that use and storage areas that are indoors must be ventilated either mechanically or naturally, so long as the natural ventilation has proved to be sufficient for the gas utilized. If using a mechanical ventilation process, the system must operate while the building is occupied, with the rate of ventilation being no less than 1 ft3/min per square foot of floor area of storage/use and having an emergency power system for alarms, vents, and gas detection. The system is also tasked with accounting for gas density to ensure adequate exhaust ventilation. Part III of this series will detail 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 elaborate on our discussion selectively explaining some of the primary areas and requirements for hydrogen installation in terms of separation and controls.Section 7.1.6.2 of NFPA 55 states that any flammable or oxidizing gases must be separated by 20’ from each other, while section 7.1.6.2.1 states that this space can be limitlessly lowered 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 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 operate fail-safe. Section 2703.2.2.1 of the IFC requires 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 demands that these brazing materials should have a melting point greater than 10,000°F.Aside from piping requirements, these codes also call for the employment 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 that details the the proper use of hydrogen in labs, we will conclude our discussion by explaining uses where the Maximum Allowable Quantities (MAQ’s) is less than the demand for hydrogen gas cylinders.

It is not unusual to come across installations in which the need for hydrogen is bigger than the MAQ’s, usually in instrumentation applications 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 unable to be obtained . The NFPA 55 code and the IBC and IFC requirements make it possible for these volumes exist within a building; however, important enhancements to the building are needed, effectively dictating that a hydrogen shelter be built by the facility. These upgrades are comprised of advancements to the structure fire rating, transportation, fire detection, a restraint on the amount of occupants, and a building story limit. These installations also have strict distancing requirements and floor and wall ratings as well. 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 numerous, smaller systems within which the compressed gas cylinders can be installed entirely in gas cabinets.

Fresno Oxygen & Welding Supplies/Barnes Welding Supply is a trusted132] provider of hydrogen, along with many other specialty gases and specialty gas equipment to the Fresno area. Whether you are in search of specialty gases for use in your laboratory research, or any other industry in Fresno, Fresno Oxygen & Welding Supplies/Barnes Welding Supply will have the products you need to get the job done. To find out more about Fresno Oxygen & Welding Supplies/Barnes Welding Supply and our specialty gas products in Fresno, browse our website and catalog. We can be reached at 559-341-4456 or via email at info@barnesspecialtygases.com
 
 
 
Larry Gallagher
CONCOA 
2/10/2016