Sanitary Gas Filter Housing Installation Guide: A Complete Process from Preparation to Validation

In industries with stringent air quality requirements—such as healthcare, food processing, and pharmaceuticals—sanitary gas filter housings serve as the critical defense safeguarding clean environments. Proper installation not only impacts filtration efficiency but directly influences the safe and stable operation of the entire system. This guide systematically outlines professional installation methods for sanitary gas filter housings, helping you avoid common pitfalls.

Meticulous Preparation Before Installation

Environmental assessment and cleaning are the foremost tasks before installation. Conduct thorough cleaning and disinfection of the operating environment to ensure a relatively sealed, dust-free, and sterile space. Continuously test the air conditioning or ventilation system to confirm ductwork integrity (air leakage rate ≤1%). Additionally, the installation site must be adequately lit to facilitate detailed inspection and precise operations.

Equipment and Component Inspection is critical. Use anti-static tools when unpacking and meticulously examine the filter media for pinhole-like damage (recommended using a 600lux light source for transparency testing). Verify the airflow direction arrows marked on the filter frame and confirm the integrity and absence of deformation in the sealing gasket. For sanitary-grade stainless steel filters, additionally inspect the mirror polish finish inside the housing to ensure no sanitary dead zones exist.

Personal Protection and Tool Preparation form the foundation of safety assurance. Operators must wear sterile protective clothing, gloves, goggles, and other protective equipment. Prepare specialized installation tools such as explosion-proof electric torque wrenches and laser alignment devices. In medical settings, adopt the “double-bag method” for packaging removal: outer packaging is opened in the buffer room, while inner packaging is opened at the installation site after ethanol spray disinfection.

Detailed Standard Installation Procedure

Filter Positioning and Orientation Verification is the first critical step. During installation, always verify the air inlet/outlet directions marked on the filter housing to ensure correct airflow orientation—typically inlet on the outer side, outlet on the inner side**. For ceiling-mounted supply air systems, use a laser alignment tool to adjust filter levelness (deviation ≤2mm/m). Incorrect orientation damages the filter media structure, significantly reducing filtration efficiency.

Sealing Treatment directly impacts filtration performance. Apply sanitary-grade sealant (e.g., medical-grade silicone) evenly within the frame groove, maintaining a recommended bead thickness of 3-5mm. For filters with O-rings, moisten the O-ring and filter element seat socket with purified water or suitable lubricant before installation to facilitate insertion and ensure proper sealing. Multi-element filters require clamping plates to secure each element evenly.

Connection and Securing must follow standardized procedures. Smoothly integrate the filter housing into the piping system, avoiding forced alignment during connection. When using mechanical clamping devices, apply pressure in stages: first pre-tighten at 50% of design pressure, then increase to 80% after 30 minutes, finally reaching full pressure. For large filters, maintain a clamping force gradient within 15-20 N/cm².

Considerations for Special Application Scenarios

Medical Facility Installation imposes extremely stringent requirements. In areas such as operating rooms, ICUs, and laboratories, surface microbial sampling must be conducted immediately after filter installation. For precision equipment rooms like MRI suites, install silicone vibration isolation pads (≥8mm thick) between the filter and frame to effectively reduce frame cracking rates. In negative pressure applications like central suction systems, filters must be mounted on platforms elevated above the liquid level, with high-performance check valves installed at the exhaust end.

Achieving steam sterilization capability is critical for certain applications. If filters require steam sterilization, appropriate steam traps must be installed on steam lines to ensure complete drainage of condensate before use. Sanitary filters are typically sterilized periodically with 121°C clean steam, but **steam pressure must not exceed 0.1-0.3 MPa**. Valves should be opened and closed slowly, and sterilization should be supervised by designated personnel.

Pre-filter protection strategies extend the service life of primary filters. For handling highly contaminated air (e.g., containing significant particulate matter or microorganisms), pre-filter equipment is recommended. Air entering sterilizing filters must first pass through an air receiver for pressure stabilization and pre-filtration. Failure to do so will significantly reduce the sterilizing filter cartridge's lifespan and compromise sterilization efficacy. Replace pre-filters when their differential pressure reaches 0.03-0.04 MPa.

Post-Installation Validation and Testing

In-situ leak testing is the core procedure for verifying installation quality. Use PAO or DOP particle generation methods for detection, maintaining upstream concentrations between 20-80 μg/L. During scanning, probe movement speed must not exceed 5 cm/s. For medical-grade HEPA filters, the local leakage rate must not exceed 0.01%. Focus inspection on critical areas such as filter-to-frame joints and pleated separators.

Resistance monitoring and recording establish benchmarks for subsequent maintenance. Installing differential pressure sensors (range 0-500 Pa, accuracy ±1%) is recommended. Initial resistance should not exceed 115% of the rated value. Record parameters including filter serial number, installation location, and initial resistance, establishing an electronic archive. Per relevant standards, medical filter replacement records must be retained for three years after equipment decommissioning.

Performance Validation ensures filters meet operational requirements. After equipment startup, use a particle counter to verify post-filtered air particle counts remain below specified thresholds (e.g., ISO Class 5 cleanliness). Monitor resistance changes; investigate abnormal initial pressure differentials for seal integrity or membrane damage. Only validated filters may enter operational service.

Maintenance and Filter Replacement

Routine Monitoring is essential for sustained performance. Regularly inspect filters for external damage or membrane clogging, and assess operational status using differential pressure gauges or flow meters. Consider replacing the filter element when the pressure drop between upstream and downstream exceeds 0.05 MPa or when airflow rate significantly decreases. Verify filtration efficiency monthly using a particle counter to ensure continued compliance with sterilization requirements.

Filter element replacement operations must strictly adhere to safety protocols. Operators must wear full personal protective equipment—goggles, masks, and protective suits—during replacement. Steam sterilization is recommended before replacement; alternatively, inject 75% ethanol into the filter and maintain for 30 minutes. Discarded cartridges constitute infectious waste and must undergo proper disposal as infectious contaminants; never discard them carelessly.

Maintenance Cycle Planning is determined by usage conditions. Generally, sterile filters require cartridge replacement every 3-6 months or after 100 steam sterilization cycles. Immediate replacement is required when filtration efficiency drops below 99.95% (for 0.3μm particles) or when resistance reaches twice the initial pressure drop. For pre-filters, consider maintenance or replacement when the differential pressure reaches 0.03-0.04 MPa.

Proper installation of sanitary gas filter housings is the fundamental guarantee for ensuring clean environments meet standards. Adhering to the above specifications not only extends filter lifespan but also provides critical environments with clean gas that complies with standards. If you encounter specific issues during installation, consult professional technicians for tailored guidance.