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Wholly Owned Subsidiary of Flanders Corporation |
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PrecisionScan |
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In-place acceptance or surveillance testing of standard HEPA filters, after the filters have been installed, is a common requirement for users of HEPA filters systems. This in-place testing is necessary to insure that an installed filtration system meets minimum specified filtering efficiencies. Many HEPA filter systems are associated
with "critical applications". A critical application is one
that uses material in Most installed filter systems are in-place tested per ASME N510, "Testing of Nuclear Air Treatment Systems". The ASME N510 test determines the gross aerosol bypassing the HEPA filter(s). The N510 test procedure requires that the filter system meet a series of pretests to assure testability. After the pretest are completed, a challenge agent is injected upstream of the HEPA filter(s). An upstream concentration is determined, and a system penetration is calculated. The penetration is compared to the acceptance criteria. The system passes, and is operational, or fails and requires corrective action. A filter system can have some penetration, and still meet the system acceptance criteria. This penetration may be due to a "pinhole" in the filter media, or any number of other reasons. If a leak is a large one, the filter will have unacceptable gross penetration. But, if the leak is small enough, any penetration would be diluted by surrounding clean air, the leak will remain undetected. The material used in some laboratories is so dangerous that the N510 overall in-place leak test method alone may not be adequate. That is, any leaks - no matter how small - are unacceptable. The capability to detect and accurately locate pin hole leaks becomes imperative. Scan testing provides this capability. Some types of HEPA filters are routinely scan tested during factory production test to locate pinhole leaks. Installations such as cleanrooms customarily use the scan test as an acceptance test. Scan testing, with the use of the Flanders/CSC PrecisionScan Test Sections, will also locate pinhole leaks in filters installed in side access filter housings. Flanders/CSC PrecisionScan Test Sections have been designed to complement the side access filter housing, and provide the user the capability to perform in-place scan testing of HEPA filters installed in them. The PrecisionScan Test Sections are an integral part of the system pressure boundary. All Flanders/CSC PrecisionScan Test housings are designed for high integrity and built to the same leak tightness and quality standards as the containment filter housings.
A wide assortment of options are available for all housings. |
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process which could be harmful to health and surrounding areas. In these
critical applications, the installed filters must remove the dangerous
material. Appropriate regulatory agencies often mandate in-place testing
as a prerequisite before the critical filter system becomes operational.