Canadian Occupational Safety

October/November 2019

Canadian Occupational Safety (COS) magazine is the premier workplace health and safety publication in Canada. We cover a wide range of topics ranging from office to heavy industry, and from general safety management to specific workplace hazards.

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Page 25 of 35

26 Canadian Occupational Safety arly one morning in October 2017, an auto- matic gas detector alarm went off in an ice rink in Fernie, B.C. It had been triggered by an ammonia leak coming from a small hole in a tube in the rink's chiller, which helps create ice for a hockey and curling rink. The leak had been detected earlier in the year. With the refrigeration equipment shut down, three workers started trying to repair it, but there was a large burst of ammonia from the chilling unit. All three men — two city employees and a refrigeration mechanic — were killed. In 2010, a maintenance contractor had advised replacing the system, but the City of Fernie, after initially sched- uling funding to replace the system, eventually deleted the project from its budget. "Ammonia can be used very safely, but if equipment is not maintained, if end-of-life strategies are not adhered to, then major failures can happen," says Eric Lalli, leader, incident investiga- tions and provincial safety manager at Vancouver-based Technical Safety B.C. Combustion systems provide heat for industrial processes that alter the physical and sometimes chemi- cal properties of materials. They are common to a vast array of work- places. They are also — because they function by the burning of hazard- ous fuels — very dangerous. When things go wrong, they can lead to seri- ous injuries, fatalities and significant damage to equipment and facilities. Every company using combustion systems must implement a safety pro- gram focused on regular maintenance, inspection and training. Combustion systems are used in almost all manufacturing workplaces, from food processing to the automo- tive and pulp and paper industries, says Robert Sanderson, director of business development, combustion safety, at Rockford Systems, based in Rockford, Ill. Companies make use of thermal energy processes in many types of metal treating, such as painting, baking, sintering (making a powdered material into a solid mass by heat without melting) and annealing (a heat treatment used to reduce the hardness of a material). They are also used to dry paint, lacquer and enamel on manufactured articles, a process that often involves heating the articles in an industrial drying oven. "Look around a room. Just about everything you can see has been kissed by the heat of an industrial process, whether it is the paint on the walls; the upholstery that may have been dyed and then baked to dry it on; the plastic which may have been thermally moulded; or the adhesive in the carpet- ing," says Sanderson. Industrial heating equipment includes dryers, furnaces, heaters and ovens. These usually supply heat to a work chamber and use a heat source (electricity or burning fuel). Industrial boilers heat water or generate steam for industrial processes or heating applications. Boilers are used in the chemical, food processing, paper, refining and primary metals industries. The fuel piping system, or fuel train, is a series of components that feed and control the pressurized fuel to an industrial burner. Valves regulate the pressure and amount of gas flowing through the unit. Key safety features include safety shutoff valves, vent valves, visual-indication mechanisms and proof-of-closure switches. These key safety features are part of a "valve safety train," whose main function is to isolate fuel from the oven, furnace or other appliance, adds Sanderson. A valve safety train typically consists of these components plus regu- lators, in-line strainers, sediment traps, manual valves, throttling valves, pres- sure switches and test fittings linked to a burner management system. The primary fuel used by most com- panies in Canada and the United States is natural gas. Other industrial gases are sometimes chosen: propane may be the second most commonly used and, after that, butane or other specialized atmospheric acids. Fuels such as coal vapours, solids or wood pulp are not used. Some companies use electric heat, which is less economical than gas. "It all depends on the process. Most users use some type of fuel for their heating. If they are using electrical, it's often because there's a specific process need that precludes gas. Gas is almost always less expensive than electricity," he says. "More and more [users] are shifting to natural gas as coal plants are shuttered in favour of natural gas. There's a continual increase in the uptick in the use of natural gas, whether it be new industries or shifting of the combustion market." Poorly designed and maintained combustion systems can result in serious incidents, such as leaks of hazardous gas from piping systems. One major danger is carbon monox- ide, which causes asphyxia. Fires and explosions, which can send burning equipment, debris and pipes flying in all directions, cause severe burns and even death. "The risk is not just for the workers near the equipment but also for people in the surrounding areas. If you have an explosion, it's not just the guy who's working on the boiler; it's whoever else is working in the area as well who could be injured," says John Marshall, director of fuels safety at Toronto- based Technical Standards and Safety Authority (TSSA), which registers all contractors handling fuels and certi- fies trades people who work with fuels. Moreover, these explosions can inflict terrible damage to workplace equipment and to the buildings them- selves, he adds. "We've had explosions and fires that destroy whole buildings." MAINTAIN, INSPECT AND TEST Problems can occur when combus- tion system equipment is not in good operating condition. Routine mainte- nance, regular inspection and testing — completed by certified technicians and according to equipment manu- facturers' instructions — are critical to prevent incidents. First, safety managers need to ensure they are buying equipment from certi- fied suppliers, which means equipment that meets the standards, codes and regulations of the jurisdiction in which they work. For example, valve safety trains, which control the flow of the gas, are designed to meet a variety of international safety standards, includ- ing the NFPA (National Fire Protection Association), NEMA (National Electri- cal Manufacturers Association), CSA (Canadian Standards Association), UL (Underwriters Laboratory) and FM (Factory Mutual Insurers). The correct installation of the com- bustion system is essential; mistakes here can cause serious problems. For example, if the venting equipment is not properly installed, the products of Without proper management, combustion systems can cause severe injuries and major damage to a workplace HEAT E The is on By Linda Johnson

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