{"id":6100,"date":"2026-09-18T14:52:09","date_gmt":"2026-09-18T06:52:09","guid":{"rendered":"https:\/\/www.bacintl.com\/?p=6100"},"modified":"2026-09-18T08:37:29","modified_gmt":"2026-09-18T00:37:29","slug":"practical-guide-for-storage-installation-and-pao-leak-testing-of-mini-pleat-hepa-filters","status":"publish","type":"post","link":"https:\/\/www.bacintl.com\/es\/practical-guide-for-storage-installation-and-pao-leak-testing-of-mini-pleat-hepa-filters\/","title":{"rendered":"Practical Guide for Storage, Installation and PAO Leak Testing of Mini-pleat HEPA Filters"},"content":{"rendered":"

\"\"<\/p>\n

After the filters arrive, first check the integrity of outer packaging to confirm no rain exposure or extrusion damage. The storage environment must be an indoor dry and clean warehouse, with ambient temperature maintained at 5~35\u2103 and relative humidity \u226470%. Keep away from heat sources, organic solvents and areas with volatile disinfectant chemicals to prevent hot-melt adhesive and filter media from erosion by chemical gas. Do not remove the original factory packaging of filters before installation; the packaging provides dust-proof and anti-collision protection.<\/p>\n

Stacking must be carried out horizontally with the filter media side facing down. Vertical placement and inverted stacking are prohibited. Heavy objects shall not be stacked on the cabinet, as extrusion will cause pleat deformation of filter media and separation of adhesive lines. Control the number of stacked layers to avoid compression damage to products at the bottom. Implement FIFO (First-In-First-Out) inventory management and avoid long-term stockpiling. During unpacking sampling inspection, visually check the integrity of filter media surface, free of damage and collapsed pleats. The frame shall be free of warping and deformation, and the knife-edge sealing surface shall be free of collision notches. Once the filter media or adhesive lines are damaged, the filter shall be scrapped directly, and on-site repair is not feasible.<\/p>\n

Handling and hoisting are high-risk stages for damage. Dragging the filter housing and hitting the filter media side with hard objects are strictly prohibited. After unpacking, the filter media is fully exposed; sharp tools and sheet metal edges must not contact the filter media surface. Filters matched with FFU units are relatively light. For manual handling, hold the frame with both hands instead of grasping one side of the frame with a single hand to prevent frame distortion. For hoisting of large-size filters, use soft slings. Steel wire ropes shall not be directly bound to the filter body to avoid frame extrusion and deformation. Reduce large swinging during transportation to prevent collision.<\/p>\n

\"\"<\/p>\n

Two mainstream installation scenarios: FFU<\/a> unit installation and ceiling air supply outlet installation. FFU Unit Installation: Before installation, thoroughly clean the interior of FFU cabinet to completely remove sheet metal debris, insulation residues and metal burrs. Residual impurities will scratch the filter media or get trapped on the sealing surface and cause leakage. Inspect the sealing ring in the FFU sealing groove to confirm that the sealing ring has no fracture or permanent compression deformation, and no dust particles inside the groove. Silicone rubber and EPDM are preferred materials for sealing rings; ordinary sponge sealing rings are not recommended. Put the filter smoothly into the FFU frame, ensure the filter frame is fully fitted with the sealing ring, and tighten the compression blocks evenly. Moderate tightening force is required; violent single-point compression is forbidden, which may lead to warping of the aluminum alloy frame and local sealing gaps.<\/p>\n

Installation of knife-edge mini-pleat HEPA filter<\/a> for ceiling air supply outlet: Before installation, check that the knife-edge frame of the air supply outlet is straight without distortion, and the knife edge is free of burrs and corrosion. Clean dust and debris on the knife edge. Place the sealing ring to ensure it is fully seated in the sealing groove without distortion or trapped impurities. Hoist the filter smoothly into the air outlet, let it fall into place by self-weight, and tighten the compression buckles around evenly with balanced force to prevent local warping of the frame.<\/p>\n

For gel-seal type mini-pleat HEPA filters, follow the specification of gel-seal filters for installation. Focus on checking knife-edge height and chamfering. Forcible pressing down is prohibited. Let the filter sink into the gel by self-weight to avoid the gel being cut by burrs.<\/p>\n

After all installation is completed, PAO leak test cannot be carried out immediately. Start the air conditioning \/ FFU system for stable operation until the temperature, humidity and airflow state of the clean room are stabilized and the thermal expansion and contraction deformation of the frame is finished, then perform the leak test to avoid false alarms caused by temperature deformation.<\/p>\n

\"\"<\/p>\n

Key Points for PAO Aerosol Leak Test. The leak test of mini-pleat HEPA filter covers three key scanning areas: filter media body, adhesive sealing line between filter media and frame, and the sealing interface of the external sealing ring of the whole unit. All three parts must be tested. Many validation personnel only scan the filter paper surface and ignore the sealing positions of frame and sealing ring, resulting in undetected bypass leak points.<\/p>\n

Place the aerosol generator on the upstream air supply side of the filter to ensure PAO aerosol uniformly covers the entire upstream cross-section of the filter. The moving speed of the scanning probe must be strictly controlled; excessive moving speed will easily miss tiny leak points. Fully scan along the filter surface, then go around the sealing line of the four-side frame of the filter. For knife-edge structure products, the probe needs to focus on scanning the entire sealing interface where the filter frame fits the sealing ring. For gel-seal structure products, the whole sealing contact line between gel and knife edge must be fully scanned.<\/p>\n

If an alarm occurs during leak testing, eliminate false alarms first: reduce the probe moving speed and rescan the same position to confirm whether it is a real leakage. If leakage is confirmed, troubleshoot in the order from outside to inside:<\/p>\n

    \n
  1. Check the tightening state of compression buckles and FFU compression blocks to see whether insufficient compression or local over-compression causes frame warping.<\/li>\n
  2. Lift out the filter, check whether the sealing ring is damaged or displaced, and whether there are debris trapped on the sealing surface.<\/li>\n
  3. Visually inspect whether the filter frame is bumped and deformed.<\/li>\n
  4. Check whether the filter media is punctured, the adhesive lines fall off, and whether there are missing glue gaps at the peripheral glue injection positions.<\/li>\n<\/ol>\n

    If it is a sealing assembly problem, retest after removing impurities and repositioning & compressing. If the filter media is damaged, adhesive lines fall off or the frame suffers irreversible deformation, the filter shall be directly scrapped and replaced. It is not allowed to apply sealant for repair and continue to use in GMP clean areas.<\/p>\n

    Multiple prohibited operations on site: Do not store filters for a long time in humid and high-temperature environments; do not leave unpacked filters exposed to environments with organic solvents and high-concentration disinfection gas for a long time; do not knock violently or forcefully squeeze the filter into place; do not continue to use the filter with damaged filter media after installation; do not apply sealant on site to repair leakage points of the filter body.<\/p>\n

    Keep records after installation, register each filter serial number and initial pressure difference as the baseline for later operation and maintenance. bacclean provides operation guidelines for storage, handling, installation and leak testing together with delivered products. Standardized warehousing and installation procedures are the premise for mini-pleat HEPA filters to achieve designed performance, avoiding equipment damage and project validation rework caused by improper operations.<\/p>","protected":false},"excerpt":{"rendered":"

    The pleated filter media and hot-melt adhesive lines of mini-pleat HEPA filters are precise and fragile structures. Bumping, extrusion, moisture exposure and foreign object puncture will cause irreversible damage. PAO leak test failures in numerous projects are often not caused by factory defects of filters, but improper warehousing, handling, hoisting and on-site installation operations. Combined with abundant on-site service experience of bacclean, this paper sorts out the storage conditions and handling key points of mini-pleat HEPA filters, installation procedures for two scenarios including FFU and air supply outlet, practical essentials of PAO aerosol leak detection and on-site precautions, providing practical reference for EPC construction, validation teams and workshop operation & maintenance personnel.<\/p>","protected":false},"author":3,"featured_media":6101,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-6100","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/comments?post=6100"}],"version-history":[{"count":2,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6100\/revisions"}],"predecessor-version":[{"id":6105,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6100\/revisions\/6105"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media\/6101"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media?parent=6100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/categories?post=6100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/tags?post=6100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}