What are the daily maintenance precautions for liquid tank air supply outlets?

The daily maintenance of the liquid tank supply air outlet needs to take into account the sealing performance, cleanliness, equipment stability, and operation standardization. The following are the key precautions and operation points:
I. Precautions for Cleaning and Sealing Maintenance
Avoid damaging the surface and the sealing structure
Selection of cleaning tools: Use a soft lint-free cloth or sponge. Do not use sharp tools such as steel wool balls or hard scrapers to prevent scratching the surface coating of the air supply outlet or the edge of the liquid tank.
Cleaning agent restrictions: Prioritize the use of pure water or neutral cleaning agents (such as 75% alcohol), and avoid using strong acids, strong alkalis, or solvent-based cleaning agents (such as banana water) to prevent corrosion of the sealant or metal parts.
Key points of liquid tank inspection:
Sealant needs to be observed regularly (at least once a month). If cracking, bubbles, hardening, or peeling are found, the old sealant should be removed in time and reapplied to ensure that the sealant remains continuous without any breaks.
It is strictly prohibited to leave any debris (such as screws or debris) in the liquid tank to avoid affecting the installation and sealing performance of the filter.
2. Prevent secondary pollution
Before cleaning, wear clean suits and gloves to prevent human hair and grease from contaminating the air supply outlets.
The garbage generated during the cleaning process (such as dirty clothes and waste glue) should be promptly taken out of the clean room and must not be piled up on site.
If the cleanroom grade is relatively high (such as ISO grade 5 and above), after cleaning, a particle counter should be used to detect the surrounding environment to confirm that there is no new contamination.
Ii. Operating Specifications for Filter Replacement
Strictly follow the replacement process.
Shutdown and power-off: Before replacement, the air supply system must be turned off and the power cut off to avoid triggering the electrical control components or fan operation during operation, which may cause safety risks.
Treatment of old filters:
High-efficiency filters may adsorb harmful particles (such as microorganisms and chemical pollutants) and need to be disinfected and sterilized first (such as by spraying formaldehyde solution or ultraviolet irradiation) before disassembly.
When disassembling, handle it with care, take it out vertically, and avoid tilting to prevent dust from spilling and contaminating the clean room.
Key points for installing the new filter:
Before installation, it is necessary to check that the model and size of the filter match the liquid tank and confirm that there is no damage or deformation.
The filter and the liquid tank must be fully adhered to. The sealant should evenly fill the gap (with a thickness of approximately 3-5mm), and be fixed with pressure strips or screws to prevent displacement.
2. Leak detection tests cannot be omitted
After the high-efficiency filter is installed, a PAO leak test (aerosol scan) must be conducted. Use a photometer to detect the leakage rate at the edge of the filter and the connection of the liquid tank, ensuring that the leakage rate is less than 0.01%.
If leakage is found, the position of the filter needs to be readjusted or the sealant reapplied until the test is qualified.
Iii. Key Points for Maintenance of Transmission and Electrical Components
Lubrication and fastening of mechanical components
Air valve and actuator:
Check the opening and closing flexibility of manual air valves monthly, and test the accuracy of the electric actuator stroke and the sensitivity of the limit switch of electric air valves quarterly.
The transmission components (such as gears and pins) should be lubricated with food-grade grease (specifically designed for clean rooms) every six months to prevent the evaporation of ordinary grease and environmental pollution.
Fan (such as FFU) :
Do not touch the impeller when the fan is in operation. Check if there is any dust accumulation or deformation on the impeller. Blow off the internal dust with compressed air every year.
If the temperature rise of the bearing exceeds 60℃ or abnormal noise occurs, the machine should be stopped immediately for inspection to prevent the bearing from seizing and damaging the fan.
2. Electrical safety and anti-static
Check whether the power cord is damaged or aged and whether the joints are loose. Do not operate electrical components in a humid environment.
Clean rooms need to maintain static electricity control (such as laying anti-static flooring on the floor), and maintenance personnel should wear anti-static wristbands to prevent static electricity from damaging the electric actuator chips or causing sparks.
Iv. Environment and Record Management
Control the temperature and humidity of the environment.
The supply air outlet is constantly exposed to a high-temperature (> 28℃) or high-humidity (RH > 70%) environment, which can easily lead to accelerated aging of the sealant and rusting of metal parts. It is necessary to strictly control the humidity of the clean room temperature through the air conditioning system (it is recommended to have a temperature of 20-24℃ and a humidity of 45%-65%).
During the rainy season or in humid areas, the operating time of the dehumidifier can be increased, and it is necessary to regularly check whether there is condensate water on the back of the air supply outlet.
2. Establish a detailed maintenance ledger
The recorded content should include:
Maintenance date and personnel: To facilitate responsibility tracing.
Maintenance items: such as cleaning, filter replacement, sealant repair, etc.
Consumable information: filter model, sealant batch, grease type, etc.
Test data: pressure difference value, leak detection result, fan operation parameters, etc.
By analyzing trends through ledgers (such as shortened filter replacement cycles), potential problems like system leakage and fresh air pollution can be detected in advance.
V. Professional Operation and Safety Instructions
Unauthorized operations are prohibited.
Key steps such as the replacement of high-efficiency filters, the maintenance of electrical circuits, and the application of sealant must be carried out by professionals who have received training in clean rooms. Ordinary personnel are not allowed to disassemble core components without authorization.
If the supply air outlet integrates sensors (such as wind speed sensors or differential pressure sensors), calibration or replacement must be carried out by the manufacturer's technicians to avoid data distortion caused by misoperation.
2. Safety protection measures
When maintaining high-altitude air supply outlets (such as those above suspended ceilings), it is necessary to set up stable scaffolding or use lifting platforms, and wear safety belts to prevent falls.
When dealing with old high-efficiency filters, if they involve biosafety laboratories (such as P3 and P4 laboratories), they should be treated as hazardous waste. First, they need to be sterilized under high pressure and then transported in a sealed manner to prevent the leakage of pathogenic microorganisms.
Vi. Maintenance Tips for Special Scenarios
1. Reactivate after a long period of shutdown
If a cleanroom is shut down for more than one week, before it is reactivated, the following are required:
Thoroughly clean the surface of the air supply outlet and the liquid tank, and check whether the sealant has cracked due to changes in the shutdown environment.
Test whether the fan and air valve are operating normally, conduct a full system leak check, and ensure that the cleanliness meets the standards before putting it into use.
2. High-pollution scenarios (such as pharmaceuticals and chemicals)
The maintenance frequency needs to be increased to twice a week for cleaning and once every two weeks for sealing inspection, as contaminants (such as dust and chemical vapors) may accelerate the corrosion of components.
After coming into contact with corrosive contaminants, the surface of the supply air outlet should be immediately rinsed with deionized water and dried to prevent residue.
By strictly implementing the above precautions, the service life of the liquid tank supply air outlet can be maximally extended, ensuring that the clean room always meets the air quality requirements for production or scientific research. If the equipment experiences complex malfunctions (such as fan burnout or structural damage to the liquid tank), it is recommended to contact the manufacturer's after-sales service promptly to avoid disassembling it by yourself, which may lead to the expiration of the warranty.