S k industries manufactures metal frame separator style hepa filters. These are applied in the application with high temperature requirements up to 1,000 f [540 c] for exhaust air only and 500 f [260 c] for supply air. These filters are provided with either a gasket or fluid seal. It has minimum efficiency of 99.97% on 0.3 microns when tested at rated capacity on a q-107 test rig. Each filter is challenged with an approved nearly mono dispersed oil aerosol of 0.3 micron size and by measuring the upstream and downstream concentration of these particles with a light scattering photometer, the penetration can be determined and the efficiency can be calculated. The media pack and pack-to-frame seal is scanned using a photometer or particle counter to insure that there are no leaks greater than 0.01% of the upstream concentration at 100 fpm face velocity. Scan testing is only available for the 500 f [260 c] model. The company provides two types of sealants for the filters. Silicon sealant: this is high temperature [rtv] silastic silicon compound rated for continuous service up to 500 f [260 c]. Glass pack sealant: the glass pack seal is rated for continuous service up to 1000 f [540 c] in exhaust air applications only. It is a mat of sub-micron glass fibres that creates a seal when compressed between the filter pack and filter frame.
