Standardized Use and Maintenance Methods for Horizontal Flow Class-100 Clean Workstations The core value of horizontal flow clean workstations is to provide a dust-free and clean environment of 100-level (ISO 5 class) through stable horizontal laminar flow. The core principles for its use and maintenance are: reducing air turbulence, strictly controlling the cleanliness of the operation area, regularly ensuring the filtration efficiency, and maintaining the stability of the laminar flow. All operations should be carried out in accordance with these principles. At the same time, considering its characteristic of “air flow blowing directly from the back to the front without personnel protection capability”, standardized usage and maintenance procedures should be formulated. The following are practical operation guidelines that can be directly implemented, including the entire operation process (before startup / during operation / after shutdown), daily and regular maintenance, common fault troubleshooting, and core prohibitions. They also take into account operability and compliance. I. Standardized Use Procedure (in stages, directly executable) The laminar flow field of horizontal flow clean workstations is prone to be disturbed by external forces. The standardization of operation directly determines whether the cleanliness is met. It is necessary to strictly follow the “preparation before startup →

Specification for Filter Replacement of Horizontal Flow Cleanroom Workstations (Primary Efficiency + High Efficiency) The filters of horizontal flow cleanroom workstations are divided into primary efficiency filters (preliminary protection, washable / replaceable) and high-efficiency filters (HEPA/ULPA) (core filters, not washable, as the core item for replacement). The replacement procedures, timing, and operation requirements for the two types are significantly different. The core principle of replacement is: power-off operation, clean protection, model matching, strict sealing, and verification after replacement. The entire process should avoid introducing dust pollution into the duct, ensuring that the operation area reaches 100-level (ISO 5 grade) cleanliness after replacement. The following are the direct and applicable replacement steps for each type, including replacement timing, preparation, practical operation, and verification throughout the process. Core prerequisite: Determine the replacement timing (avoid blind replacement / overuse) 1. Replacement timing for primary efficiency filters (priority cleaning, replace if not recoverable) The primary efficiency filter is a washable consumable. First, clean it according to maintenance requirements with water / compressed air. Replace it if any of the following situations occur: After 2-3 cleanings, the filter screen is deformed or damaged, or the surface dust cannot be completely removed, and the airflow speed

The core feature of the horizontal flow ultra-clean workstation is that the airflow is sent forward horizontally from the rear of the operation area, forming a uniform horizontal laminar flow, providing a 100-level (ISO 5 grade) dust-free and clean environment for samples. It is mainly designed to offer a sterile environment of 100-level protection for samples, without providing personnel biological protection capabilities. It is only suitable for operations without biological hazards, toxicity, or harmful aerosols. All applicable scenarios are centered around the core principle of “only needing to isolate external dust and particles to ensure sample cleanliness, and the operation process poses no direct safety risk to personnel”. The specific sub-scenarios are as follows: 1. Core applicable prerequisites Before use, the following basic conditions must be met; otherwise, this equipment is strictly prohibited from being selected: The operation objects, reagents, and samples have no pathogenicity, no infectivity, no microbial proliferation risk, and do not contain pathogenic bacteria, viruses, fungi, etc. of biological hazards. The operation process does not produce toxic, harmful, corrosive, or volatile gases, and does not form harmful aerosols to the human body. The core requirement is only to prevent the contamination of samples by dust, hair, fibers,

First, clarify the core concepts: A clean bench is a general term for a type of purification equipment that provides a local high-cleanliness environment. Horizontal flow workbenches and vertical flow workbenches are the two main types of clean benches classified by the direction of air circulation. These two are not separate devices from the clean bench but are two branches of the clean bench. The core differences lie in the direction of air flow, protection, and application scenarios. I. Core Definitions 1. Clean Bench It uses three-stage filtration (initial filter, intermediate filter, and high-efficiency air filter (HEPA/ULPA)) to purify the air, and then delivers it in a laminar flow to the operation area, creating a local ISO 5-level (hundred-level) ultra-high cleanliness environment. It prevents external pollutants from entering the operation area and avoids the diffusion of pollutants within the operation area. It is widely used in research and production scenarios with extremely high cleanliness requirements. 2. Vertical Flow Clean Bench The mainstream type of clean bench. The air flows vertically downward from the top of the clean bench and uniformly passes through the operation surface. Some of the air flows are purified through the return air inlet at the bottom

The differential pressure reading of the wind shower transfer window is unstable. The essence of this problem is caused by fluctuations in the pressure sampling signal, chaotic airflow, or faults in the instrument itself. Following the “from easy to difficult, from external to internal” approach, it can be classified into four major types of causes, each with corresponding typical manifestations and handling methods. 1. Problems with the differential pressure gauge and the pressure guide pipe (the easiest to troubleshoot, prioritize inspection) This type of problem directly affects pressure collection, and is a common cause of fluctuating and erratic readings. Leaking, loosening, or detachment of the pressure guide pipe Seams in the pressure guide pipe joints or pipelines allow outside air to enter, causing the sampling pressure to fluctuate up and down, and the pointer to swing back and forth. Solution: Check the positive and negative pressure ends of the joints, re-tighten them; replace the damaged pipelines to ensure a sealed pipeline. Blockage, bending, or water accumulation in the pressure guide pipe Dust or oil contamination blocking the pipeline, or bent pipelines with condensate water, causing pressure transmission to be obstructed and discontinuous, and the pointer to fluctuate irregularly. Solution: Use

The differential pressure gauge reading of the air shower transfer window is unstable. The step-by-step solution approach is as follows: The core principle for solving the problem is to start from the easy to the difficult, from the outside to the inside, first eliminate operational and instrument issues, and then handle equipment hardware faults. Each step can be operated independently, and after completion, retest the differential pressure to ensure the reading is stable. 1. Step 1: Reset the standard working condition and eliminate invalid readings Many reading fluctuations are caused by non-compliant working conditions, not equipment failures. Complete the following operations before making a judgment: Fully close the doors on both sides of the air shower transfer window, confirm that the door bodies are fully latched and the sealing strips are in close contact, with no gaps. Remove all items from the transfer window to ensure that the nozzles and return air channels are not obstructed, avoiding air flow disorder. First clean / inspect the primary filter, remove surface dust, if it is severely clogged, directly replace it. Connect the power supply, start the air shower function, and run stably for 3 to 5 minutes. Wait until the fan speed

The ISO 5 level rapid rolling-type air shower room is applicable in the scenarios of the biopharmaceutical industry. The ISO 5 level corresponds to the US Federal 209E 100 level, which is the mandatory clean level for the core production process of biopharmaceuticals. It requires strict compliance with GMP regulations to control particle and microbial contamination. The rapid rolling-type air shower room, with its large opening, high opening and closing speed, and the ability to accommodate pallets / large-sized goods, as well as strong sealing partitions, has solved the problem of efficient and clean transportation of large quantities and large-sized materials in the biopharmaceutical industry. Its applicable scenarios cover the entire logistics chain of biopharmaceutical production, research and development, storage, and waste disposal, as follows: 1. Core sterile workshop raw materials and packaging material input scenario This is the most core application scenario of this type of air shower room, responsible for purifying the production front-end materials and sending them into the ISO 5 level sterile core area, eliminating pollution at the source. Sterile raw materials batch transportation Applicable to injection raw materials, sterile auxiliary materials (such as mannitol, glucose, medicinal ethanol), biopharmaceutical culture media, adjuvants, plasmids, etc., in the

ISO 5 level (formerly Class 100) belongs to an extremely high level of cleanliness. It has extremely strict control over the concentration of particles in the air with a size of ≥ 0.5 μm. It is suitable for high-precision fields that have zero tolerance for dust and microbial contamination. When combined with a rapid rolling-type air shower room, it can not only meet the extremely high cleanliness requirements but also adapt to the frequent and rapid turnover of goods. The core application industries and specific scenarios are as follows: 1. Semiconductor and microelectronics industry (the most typical field with ISO 5-level cleanliness requirements) This industry is the most typical field with ISO 5-level cleanliness requirements. Even tiny particles can cause the failure of chips and wafers. High-cleanliness air shower rooms must be used to achieve dust removal and clean isolation of materials. Core scenarios: Core process areas such as lithography, etching, film deposition, and ion implantation in wafer manufacturing plants, used for transporting wafer boxes, photomask plates, high-purity chemical reagents, and precision manufacturing components; Clean areas for packaging and testing of high-end chips and storage chips, transporting chip products, packaging substrates, and precision testing fixtures; Core process areas for the

DOP/PAO High-Efficiency Leak Detection Core Criteria (National Standard + Industry Practical Version) The DOP high-efficiency leak detection criteria are fully applicable to mainstream PAO leak detection (medium substitution, with consistent detection rules), and the core basis is the national standard GB/T 13554-2023 “High-Efficiency Air Filters”, ISO 14644-3 “Cleanroom Testing Methods”, and the mandatory requirements of the pharmaceutical/electronic industry GMP. The detection is divided into pre-calibration standards, core detection limits (by method/filter type/detection location), on-site practical detection rules, and for small clean equipment such as DOP laminar transfer windows, special detection requirements for local sealing detection need to be adapted. All detections are based on real-time detection data from portable leak detectors/particle counters, without manual subjective determination. Core Premise: Leak Detection Pre-Background Value Calibration Determination (If not met, the detection result is invalid) Before formal leak detection, the downstream background concentration of the filter must be tested to ensure that background interference is excluded. The qualification standard for calibration is as follows: Photometer method: Downstream background aerosol concentration ≤ 0.001 μg/m³, and ≤ 0.001% of the upstream proposed dust concentration; Particle counter method: Downstream 0.3 μm particle background concentration ≤ 0.1 particles/L (100-level cleanroom) / ≤ 1 particle/L (1000-level / 100,000-level).

The core principle of DOP efficient leak detection (including the general logic for PAO leak detection) DOP efficient leak detection is a classic method for verifying the integrity of high-efficiency air filters (HEPA/ULPA). The core is used to verify whether there is leakage at the filter material and sealing points (with the frame and installation surface), which is the core means for the installation and replacement of high-efficiency filters and regular verification in clean rooms (including DOP laminar transfer windows, clean benches, and air showers). Due to environmental protection requirements, currently, PAO (poly α-olefin) is commonly used to replace DOP (di-tert-butyl phthalate), and both have the same leak detection principle, only the dusting medium is different. The industry often collectively refers to it as “DOP/PAO leak detection”. The core principle of this method is based on the most easily penetrated particle size (MPPS) of the high-efficiency filter: by artificially generating a uniform 0.3μm particle size DOP/PAO aerosol, sending it upstream of the high-efficiency filter and forming a stable concentration, then precisely sampling and detecting the aerosol concentration downstream of the filter. By calculating the “upstream-downstream concentration ratio (penetration rate)”, it determines whether the filter is leaking – if the filter

The daily cleaning of the DOP laminar flow transfer window should be carried out in separate areas and for individual components. It is necessary to ensure that the cleanliness meets the usage requirements while avoiding damage to the equipment components during the cleaning process. The following are the detailed cleaning standards and procedures: Clean area / component Frequency of cleaning Applicable Scenario Explanation Inner wall, transmission platform, observation window After each use After completing the item transfer and closing the double doors, immediately clean the area to prevent the growth of residual contaminants. Sealing strip Once a day The sealing strip is prone to accumulate dust and oil stains, which directly affects the sealing performance. Frequent cleaning is required. Primary filter Once or twice a week Regular cleanroom environment; for high dust environments, it should be increased to once every 2-3 days Primary filter Once or twice a week Regular cleanroom environment; for high dust environments, it should be increased to once every 2-3 days Pressure differential gauge, control panel, door handle Once a day Prevent dust accumulation from affecting the accuracy of the instruments and the operation feel.Fan inlet grille Fan inlet grille Once a week Prevent dust accumulation

To extend the service life of the DOP laminar transfer window, a systematic maintenance system needs to be established from six dimensions: standard operation, daily cleaning, regular maintenance, management of core components, environmental control, and emergency response to faults. The following is the specific implementation guide: 1. Standard operation: The foundation for a long service life Strictly implement double-door interlock Ensure that neither the inner nor the outer doors can be opened simultaneously. After each operation, confirm that the doors are fully closed and locked Do not forcefully open or close the doors or hit the door frame with hard objects to prevent damage to the lock and sealing strips Immediately stop using the window if the interlock fails, hang a “Under Maintenance” warning sign, and contact professionals for handling Standardized item transfer Do not place items that are too heavy, sharp, hot, or corrosive, to avoid scratching the inner wall or damaging the transfer table Place items centrally to reduce contact with the inner wall and prevent blocking the laminar airflow Close the fan and ultraviolet lamp promptly after transfer to avoid unnecessary energy consumption and component wear DOP detection operation standards Strictly control the aerosol concentration and pressure