{"id":5760,"date":"2026-08-10T14:23:24","date_gmt":"2026-08-10T06:23:24","guid":{"rendered":"https:\/\/www.bacintl.com\/?p=5760"},"modified":"2026-08-10T08:37:34","modified_gmt":"2026-08-10T00:37:34","slug":"installation-precautions-for-gel%e2%80%91sealed-hepa-supply-air-outlets","status":"publish","type":"post","link":"https:\/\/www.bacintl.com\/es\/installation-precautions-for-gel\u2011sealed-hepa-supply-air-outlets\/","title":{"rendered":"Installation Precautions for Gel\u2011Sealed HEPA Supply Air Outlets"},"content":{"rendered":"
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\"\"<\/h1>\n

I. Pre\u2011installation Inspection<\/span><\/h1>\n<\/div>\n
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Installation shall commence only after air ducts and ceiling plenum compartments have been fully cleaned and the air\u2011conditioning system has been purged and commissioned to pass acceptance. Filter unpacking shall be performed exclusively inside the cleanroom, and all outer packaging shall be removed out of the clean zone to prevent filter media contamination.<\/div>\n
\"\"<\/div>\n<\/div>\n
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Verify model, specification and filter class (H13\/H14). Inspect the static pressure box welds and gel\u2011seal knife edge: the four sides of the knife edge shall be flat, corner welds shall be smoothly ground free of welding slag, burrs, distortion or twisting. Flatness of the knife edge shall be \u2264\u202f2\u202fmm per metre. A deformed knife edge will directly cause sealing leakage and shall NOT be forcibly compensated by compression blocks.<\/div>\n<\/div>\n
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Examine filter appearance: no damage to filter paper and no dents or deformation on the filter frame. Confirm that the airflow arrow on the filter points toward the static pressure box (upward); reverse installation is strictly prohibited.<\/div>\n<\/div>\n
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Maintain on\u2011site ambient temperature at 18\u201125\u202f\u00b0C and relative humidity at 40\u201160\u202f%. Low temperature will harden gel and degrade sealing performance. The gel trough must be free of water, dust and disinfectant residues; wipe and thoroughly dry the trough prior to gel pouring.<\/div>\n<\/div>\n
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II. Hoisting of Static Pressure Box on Ceiling and Duct Connection<\/h2>\n<\/div>\n
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Secure suspension rods firmly to building load\u2011bearing structures and level the box with a horizontal deviation \u2264\u202f2\u202fmm\/m. Tilted box will cause uneven gel liquid level inside the trough, resulting in insufficient local immersion depth of the knife edge and concealed leakage points.<\/div>\n<\/div>\n
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For top\u2011connected \/ side\u2011connected air duct flange joints, apply neutral silicone sealant to flange gaps to eliminate bypass air leakage. Seal all internal and external welds and assembly joints of the box.<\/div>\n<\/div>\n
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Apply continuous sealant at the joint between supply\u2011air\u2011outlet flange and ceiling panel to prevent unfiltered plenum air from infiltrating into the clean zone.<\/div>\n<\/div>\n
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For unidirectional\u2011flow areas, match filters of the same batch by resistance. The resistance deviation of each filter against the average resistance shall preferably be less than 5\u202f% to guarantee uniform air supply.<\/div>\n<\/div>\n
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III. Key Points for Gel Potting (Core of Sealing Performance)<\/h2>\n

\"\"<\/p>\n<\/div>\n

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Use only original OEM matching gel. Mixing gels from different brands is forbidden, as chemical reaction may occur and cause delamination and sealing failure.<\/div>\n<\/div>\n
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Thoroughly stir and defoam the gel before pouring into the trough. Fill to 70\u202f%\u201180\u202f% of trough depth to ensure knife\u2011edge immersion depth \u2265\u202f15\u202fmm. No air bubbles shall remain in the gel, since bubbles will form leakage pathways.<\/div>\n<\/div>\n
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Allow poured gel to stand and cure under stable temperature and humidity conditions; fit filters only after gel stabilises.<\/div>\n<\/div>\n
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When replacing old filters, completely remove aged residual gel from the trough, wipe the trough with isopropyl alcohol and allow full drying before fresh gel pouring. Do not simply pour new gel on top of old residual gel.<\/div>\n<\/div>\n
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IV. Installation of Gel\u2011Sealed Filter (High\u2011frequency GMP Non\u2011conformance Points)<\/h2>\n<\/div>\n
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Large\u2011size filters require two\u2011person handling. Wear clean\u2011room gloves, handle with care, lower vertically for one\u2011step positioning. Tilting, lateral dragging and repeated insertion\u2011removal of filters are prohibited; repeated insertion\u2011removal will tear the gel and result in permanent sealing defects.<\/div>\n<\/div>\n
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Ensure the full four\u2011sided knife edge of the filter is immersed in gel with no partial suspension or single\u2011side lifting.<\/div>\n<\/div>\n
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Tighten compression blocks diagonally and evenly with torque controlled at 8\u201110\u202fN\u00b7m. Heavy\u2011handed single\u2011side tightening shall be avoided; it will warp the filter frame, collapse filter media and cause seal failure.<\/div>\n<\/div>\n
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After filter installation, enforce a standing period of no less than 20\u202fminutes before fan startup. Immediate fan operation post\u2011installation will agitate gel by airflow impact and create gap leakage leading to failed PAO leak testing.<\/div>\n<\/div>\n
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V. Differential\u2011pressure \/ PAO Test Ports and Diffuser Plate Installation<\/h2>\n

\"\"<\/p>\n<\/div>\n

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Correctly route differential\u2011pressure sampling tubing and connect external differential\u2011pressure gauge; record initial filter resistance. Tubing shall be free of kinks and air leakage.<\/div>\n<\/div>\n
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Verify unobstructed PAO aerosol injection and sampling ports on the static pressure box; cap idle ports tightly. Ensure port sealing gaskets are properly seated to avoid port\u2011side air leakage which compromises leak\u2011test results.<\/div>\n<\/div>\n
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Fit diffuser plates securely and tighten screws evenly. Prevent deformation and collision against filter media.<\/div>\n<\/div>\n
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VI. System Commissioning and PAO Integrity Leak Test (Mandatory GMP Acceptance Item)<\/h2>\n<\/div>\n
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Perform PAO aerosol leak test only after the HVAC system runs stably at rated air volume.<\/div>\n<\/div>\n
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Carry out comprehensive scanning covering filter media surface, filter frame, gel\u2011seal knife\u2011edge interface and four\u2011corner compression\u2011block positions. Scanner traverse speed shall be \u2264\u202f5\u202fcm\/s.<\/div>\n<\/div>\n
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For H14 filters, downstream leakage rate \u2264\u202f0.01\u202f% is deemed acceptable. If leakage occurs, re\u2011position the filter first. Replace the filter if retest still fails; never simply cover leaks with sealant.<\/div>\n<\/div>\n
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Production can commence only upon passing leak test. Skipping PAO leak test before production will be regarded as a major deficiency during GMP audit.<\/div>\n<\/div>\n
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VII. Common Installation Prohibitions (Pitfall\u2011avoidance Checklist)<\/h2>\n<\/div>\n
\n
\u274c Install ceiling\u2011mounted boxes out\u2011of\u2011level, use compression blocks to force\u2011compensate distorted knife edges<\/p>\n
\u00a0<\/div>\n

\u274c Pour gel without defoaming and leave entrapped air bubbles<\/p>\n

\u00a0<\/div>\n

\u274c Fit filters with tilting, drag laterally or repeatedly insert\u2011remove to tear gel<\/p>\n

\u00a0<\/div>\n

\u274c Tighten compression blocks heavily on one side and cause uneven stress<\/p>\n

\u00a0<\/div>\n

\u274c Start fans immediately after filter mounting without required standing time<\/p>\n

\u00a0<\/div>\n

\u274c Mix gels of different brands or batches<\/p>\n

\u00a0<\/div>\n

\u274c Hand\u2011over for use without PAO leak test<\/p>\n

\u00a0<\/div>\n

\u274c Reverse\u2011mount filters with wrong airflow direction<\/p><\/div>\n<\/div>\n

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VIII. Operation & Maintenance Related Notes<\/h2>\n<\/div>\n
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Perform PAO integrity test at least once per year for Grade A\/B clean areas.<\/div>\n<\/div>\n
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Replace filters promptly when resistance rises to twice the initial resistance.<\/div>\n<\/div>\n
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For VHP fumigation environments, select VHP\u2011resistant gel. Prevent direct contact of gel with highly corrosive disinfectants.<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

In accordance with GB\/T 45128\u20112026 and EU GMP Annex1 specifications, this summary sorts out the whole-process technical standards for the installation, commissioning and maintenance of gel-seal HEPA supply air outlets based on Bacclean\u2019s engineering practice. It covers core construction procedures including pre-installation inspection, ceiling hoisting and duct sealing, gel pouring, filter positioning, accessory installation and PAO leak testing, and clarifies key technical parameters and common GMP construction errors. This paper also summarizes typical installation taboos and formulates targeted maintenance specifications such as filter replacement and regular leak detection for high-grade clean areas. Applicable to cleanroom construction disclosure and technical management, the standards effectively ensure the sealing performance and stable air supply of equipment, and eliminate leakage and contamination risks in high-level clean workshops.<\/p>","protected":false},"author":3,"featured_media":5763,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-5760","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\/5760","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=5760"}],"version-history":[{"count":1,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/5760\/revisions"}],"predecessor-version":[{"id":5766,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/5760\/revisions\/5766"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media\/5763"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media?parent=5760"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/categories?post=5760"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/tags?post=5760"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}