New integral high efficiency bag-in/bag-out HEPA modules and particulate air filters that remove up to 99.99 percent of 0.3µm particulates have been announced by Strobic Air Corp., a subsidiary of Met-Pro Corp., Harleysville, Pa. The new modules/filters for the company's mixed flow impeller technology Tri-Stack systems comply with applicable pollution abatement standards. They are offered with a variety of application-matched filter media.

Strobic Air's HEPA filter modules are designed for use in most closed-loop, controlled environment facilities where 100 percent conditioned makeup air is required. This configuration is typically used where toxic, noxious, or otherwise harmful substances are employed and their fumes are not permitted to be dispersed into the atmosphere. Applications of this type are typically found in pharmaceutical/biotech/biosafety level (BSL) laboratories, many of which work with substances at their laboratory workstations or processing areas that are prohibited from being discharged into the atmosphere.

HEPA filter modules mount on the inlet side of the company's mixed flow impeller fans and are available in individual or multiple sections for series configurations. They may be used with a variety of pre-filter, absorber, and/or HEPA filter sections. To optimize performance their design permits an unencumbered airflow through the upstream and downstream opening of the filter module. A variety of standard module sizes is available, along with appropriate filter media including either gasket-type or gel seal filters. The modules accommodate a variety of HEPA and ASHRAE filters efficiencies, with typical DOP (Dioctyl-Phatalate) efficiencies of 95 percent, 99.97 percent, and 99.99percent, at 0.3µm. Pre-filter sections are available in 2", 4", and/or 6" depths.

Filter housing (module) construction is 14 gauge stainless steel with Type 304 stainless mesh face guards. The modules are also available in a wide variety of standard ASME configurations, ranging from 24" x 24" x 11 ½" to 8" x 8" x 3 1/16", with other sizes on request. A ribbed inlet collar permits use of a PVC bag attachment which creates a barrier seal between service personnel and contaminated filters, eliminating direct contact with the filter and possible harmful particulates.

Filters for the HEPA modules are specially designed to meet rigid U.S. Army requirements and provide high dust holding capacity with long useful lives. Their outstanding performance capabilities help reduce operating and maintenance costs while enhancing operating efficiency. These filters are manufactured and tested under a quality assurance program to assure compliance with overall efficiency specifications. They are available in both standard and high capacity flow configurations depending upon requirements.

Filter modules are pressure decay tested in accordance with ANSI/ANSE-N510-1995 reaffirmed, Testing of Air Cleaning Systems. Pressure readings are recorded once a minute for five minutes, and maximum leak rate is 0-0005 CFM per cubic foot of housing volume at 10" W.G.

For additional technical information or applications assistance on the new Strobic Air Bag-In/Bag-Out HEPA modules and filters, contact Strobic Air Corp., a subsidiary of Met-Pro Corp., 160 Cassell Road, P.O. Box 144, Harleysville, Pa. 19438; (215) 723-4700; fax (215) 723-7401; email tristack@strobicair.com; or online www.choosetristack.com.