The flammability rating of a welding fume extractor filter is a legitimate concern. All welding and related high heat metal working processes expose filters to the potential for fire and/or smoldering. Ace takes this fact seriously and has built two important features into it’s line of fume extractors to help mimimize first incidents. These features are permanent mechanical sparktraps and fire resistant filters.
All 73 Series self contained fume extractors utilize permanent mechanical sparktraps. Spark traps are devices that are employed to slow and cool incoming heated air and collect heavy hot material in an isolated collection area before the air touches a filter. The units cannot be operated without the spark traps in place. Such a feature is an important and effective fire prevention tool. Not all of Ace’s competitors offer sparktraps on their extractors.
Despite the effectiveness of permanent mechanical sparktraps, random sparks, embers, and hot material can potentially still find their way to the filters. In the rare instances when that occurs, all Ace 73 Series extractors employ filters that are rated UL 900 Class 2 for fire resistance. Which is not to say the filters are fireproof, but they will burn or smolder at a moderate rate of speed and, being contained within the extractors’ cabinet, can be extinguished or allowed to burn out without danger to surrounding areas or the facilty.
A summary of the UL 900 Class 2 standard is as follows:
UL 900 Class 2: Air filters which burn moderately when attacked by flame, or emit moderate amounts of smoke, or both.
Details: Class 2 air filter media shall not produce flame or extensive sparks which are sustained beyond the discharge end of the test duct when subjected to the flame exposure test and shall not cause the development of an area of more than 9 square inches as measured below the smoke‐density time curve. Additionally, the adhesive material used for coating the filtering medium or other part of Class 2 air filter media shall have a flash point of not less than 325 degrees F.