{"id":6033,"date":"2026-09-09T09:20:29","date_gmt":"2026-09-09T01:20:29","guid":{"rendered":"https:\/\/www.bacintl.com\/?p=6033"},"modified":"2026-09-09T08:25:28","modified_gmt":"2026-09-09T00:25:28","slug":"fault-analysis-of-gel%e2%80%91seal-hepa-filters-causes-and-troubleshooting-solutions-for-leakage-abnormal-pressure-differential-and-gel-failure","status":"publish","type":"post","link":"https:\/\/www.bacintl.com\/es\/fault-analysis-of-gel\u2011seal-hepa-filters-causes-and-troubleshooting-solutions-for-leakage-abnormal-pressure-differential-and-gel-failure\/","title":{"rendered":"Fault Analysis of Gel\u2011Seal HEPA Filters: Causes and Troubleshooting Solutions for Leakage, Abnormal Pressure Differential and Gel Failure"},"content":{"rendered":"

\"\"<\/p>\n

Fault 1: Leakage detected at frame sealing interface during PAO aerosol leak test, no leakage found on filter paper<\/h2>\n

Leakage points are concentrated at the sealing interface between jelly\u2011gel and knife\u2011edge, while filter paper remains intact. This indicates no damage to filter media, and the problem lies within the sealing system.<\/p>\n

    \n
  1. Check installation seating status<\/strong> Verify whether the filter has fully settled in place by its self\u2011weight and whether locking clips are tightened with proper force. Insufficient clip tension prevents the filter from dropping into position, so the knife\u2011edge cannot fully embed into the gel. Excessive clamping force causes frame warpage and partial separation between gel surface and knife\u2011edge. Solution: Loosen locking clips, re\u2011hoist the filter to allow natural seating by gravity, then fasten clips evenly and moderately, and perform leak retest afterwards.<\/li>\n
  2. Inspect knife\u2011edge frame of gel\u2011seal air outlet<\/strong> Check for distortion, burrs, notches and corrosion on knife\u2011edge edges. Sharp burrs will cut the jelly\u2011gel during filter seating and form continuous linear leakage gaps. Damaged knife\u2011edges on old air outlets are very common in renovation projects. If burrs exist, carry out grinding and repair under shutdown condition. Replace the complete gel\u2011seal air outlet frame if knife\u2011edges suffer severe deformation or notches.<\/li>\n
  3. Check for debris trapped between knife\u2011edge and jelly\u2011gel<\/strong> Metal scraps and dust particles generated during ceiling construction may be sandwiched between knife\u2011edge and gel, creating tiny bypass leakage gaps. Lift out the filter, remove all foreign matters on knife\u2011edge, check whether gel surface is scratched, and reinstall only when gel remains intact.<\/li>\n
  4. Visual inspection of jelly\u2011gel sealing surface<\/strong> Hoist out the filter and examine the full\u2011circle gel for scratches, notches and cracks. Once the jelly\u2011gel is cut, no repair measure is available. The filter shall be directly replaced and must not be put into service.<\/li>\n
  5. Mismatched dimensional parameters between knife\u2011edge height and filter gel\u2011groove depth (hidden condition)<\/strong> Insufficient knife\u2011edge height leads to inadequate embedding depth and insufficient sealing allowance; over\u2011height knife\u2011edge presses against the groove bottom and completely crushes the gel. This is a parameter mismatch originated from early\u2011stage design\u2011selection. Verify drawing specifications of both components, adjust air\u2011outlet hardware or replace filters with compatible dimensions.<\/li>\n<\/ol>\n

    Fault 2: Passed leak test upon commissioning, intermittent sealing leakage occurs after months of operation<\/h2>\n

    Intermittent leakage poses high difficulty for troubleshooting. The unit may pass leak\u2011testing occasionally yet show leak points again when system air pressure varies. Such faults are mostly attributed to aging and damage of jelly\u2011gel.<\/p>\n

    Frequent VHP (Vaporized Hydrogen Peroxide) disinfection in pharmaceutical workshops gradually hardens the jelly\u2011gel and generates micro\u2011cracks under long\u2011term exposure to disinfection gas. Subjected to air pressure fluctuation of supply\u2011air system, cracks open and close dynamically, resulting in sporadic leakage. Troubleshooting: Refer to operation\u2011maintenance ledger of the workshop and check cumulative VHP disinfection cycles. Lift out the filter and visually inspect jelly\u2011gel for hardening and fine cracks. Replace filters with aged gel. For subsequent selection, upgrade to special VHP\u2011resistant jelly\u2011gel version.<\/p>\n

    Besides, slight deformation of ceiling air\u2011outlet frame induced by thermal expansion and contraction under temperature change may also trigger intermittent leakage, which is frequently seen in renovated workshops. Verify fastening status of ceiling air\u2011outlet frames and rationality of thermal expansion allowance design.<\/p>\n

    Fault 3: Rapid abnormal rise of filter pressure differential, insufficient air volume and air change rate in cleanroom<\/h2>\n

    \"\"<\/p>\n

    Sharp pressure\u2011differential increase is most frequently caused by failure of upstream pre\u2011filtration system. If pre\u2011filters (G4\u2011F8) are not replaced on schedule, massive dust particles directly impact HEPA filters and cause rapid clogging. Troubleshooting: Check pressure differential values of upstream pre\u2011filters and replace filter media timely if pre\u2011filtration performance degrades.<\/p>\n

    Meanwhile verify actual operating conditions of HVAC system. Confirm whether fan frequency has been reduced. Lower fan air volume will produce misleading low pressure\u2011differential readings of filters while actual supply\u2011air volume of the room becomes inadequate. Judge filter status based on pressure\u2011differential data collected under stable system conditions; do not compare with historical data directly after fan frequency conversion modification.<\/p>\n

    Another scenario: Partial blockage on filter air\u2011inlet side by thermal\u2011insulation scraps and construction debris reduces effective filtering area and leads to abnormally high pressure differential. Lift out the filter and clear upstream debris.<\/p>\n

    Fault 4: Jelly\u2011gel sagging, flowing, sticky substance precipitation<\/h2>\n

    When jelly\u2011gel sags or flows, priority shall be given to ambient temperature check. Irreversible thermal softening and melting occur when actual temperature inside ceiling plenum exceeds 70\u202f\u00b0C. Check whether gel\u2011seal filters are adjacent to high\u2011temperature pipelines and evaluate heat\u2011dissipation performance of ceiling plenum. Discard and replace filters with melted gel, and rectify heat\u2011source issues; sustained high\u2011temperature environment is prohibited for gel\u2011seal HEPA filters.<\/p>\n

    Sticky precipitation on gel surface arises from two aspects: insufficient chemical resistance of gel formulation eroded by organic solvents or high\u2011concentration disinfection gas; premature aging due to exceeded shelf\u2011life under long\u2011term storage. Evaluate process gas exposure of workshop. Select filters with chemically\u2011resistant gel formula if necessary, and optimize warehouse management to avoid overstock of filters.<\/p>\n

    Fault 5: Leak points detected on filter\u2011paper medium during leak test<\/h2>\n

    Filter\u2011paper leakage may be induced by factory\u2011originated media defects, cracking of bonding sealant between filter paper and frame caused by violent vibration and collision during transportation & hoisting, or filter\u2011paper puncture by hard objects during on\u2011site installation. Troubleshooting: Hoist out the filter and inspect filter paper for breakage as well as frame sealant for cracking. Discard and replace filters with damaged filter\u2011paper. Optimize handling and hoisting procedures to prevent heavy impact.<\/p>\n

    One confusing on\u2011site phenomenon shall be noted: transient instrument alarm triggered by excessively fast scanning speed of leak\u2011test probe does not represent real leakage. Slow down scanning speed and repeat scanning to eliminate operation\u2011caused false alarms.<\/p>\n

    General Troubleshooting Principle: External Factors First, Filter Body Second<\/h3>\n

    \"\"<\/p>\n

    Prioritize verification of system operating conditions, grille frame performance and installation practice before judging filter\u2011body defects. Do not attribute leak\u2011test alarms directly to filter quality defects. Most on\u2011site problems originate from matching components and operation workflows.<\/p>\n

    After project delivery, bacclean<\/strong> provides fault\u2011diagnosis guidelines. Our technical team supports customers to locate root causes step\u2011by\u2011step in case of on\u2011site anomalies. The complete sealing system of gel\u2011seal HEPA filters involves filter hardware, air\u2011outlet frames, transportation\u2011storage, installation and disinfection\u2011maintenance. Systematic full\u2011chain control is essential to guarantee long\u2011term stable equipment performance.<\/p>","protected":false},"excerpt":{"rendered":"

    Gel\u2011seal HEPA filters may encounter various issues during project commissioning and long\u2011term operation, such as failed PAO leak\u2011testing, fluctuating pressure differential, and damaged jelly\u2011gel seal. Faults mainly stem from three categories: manufacturing defects of the filter itself, defects of matching grille frames, and improper transportation, storage, installation and operation\u2011maintenance practices. Many fault symptoms appear similar but have completely different root causes. Without accurate fault location, repeated blind disassembly and assembly will further aggravate failures and delay project progress. This article sorts out frequent on\u2011site faults of gel\u2011seal HEPA filters, analyzes triggering factors, and provides corresponding troubleshooting ideas and solutions, assisting engineering, validation and operation\u2011maintenance personnel to quickly locate problems.<\/p>","protected":false},"author":3,"featured_media":6034,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[91],"tags":[],"class_list":["post-6033","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6033","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=6033"}],"version-history":[{"count":2,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6033\/revisions"}],"predecessor-version":[{"id":6038,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/posts\/6033\/revisions\/6038"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media\/6034"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/media?parent=6033"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/categories?post=6033"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/es\/wp-json\/wp\/v2\/tags?post=6033"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}