PSA Oxygen Generator Process Flow and Full Component Maintenance Guide

PSA oxygen generators are the core equipment for on-site oxygen production in industrial manufacturing, medical supply, and aquaculture industries, relying on pressure swing adsorption (PSA) technology to achieve efficient oxygen-nitrogen separation from ambient air. This guide details the full PSA oxygen generator process flow, step-by-step maintenance requirements for all key components, and universal maintenance principles. Following these standards can protect the core molecular sieve, extend the overall equipment service life, and ensure stable oxygen purity (≥90%) and production capacity for long-term operation.

I. Core Process Flow of PSA Oxygen Generator (4 Key Visual Steps)

The whole PSA oxygen production process is automatically cycled by a PLC control system, with the pressure swing adsorption technology as the core to separate oxygen and nitrogen from air. The 4 key operational steps are as follows:

1.1 Air Intake and Compression

Ambient air is drawn in through the air inlet and pressurized to 0.5~1.0MPa by an air compressor. This pressure range is precisely adapted to the adsorption pressure requirements of molecular sieves, providing the necessary power for subsequent oxygen-nitrogen separation.

1.2 Multi-Stage Purification and Pretreatment

Purification is a critical pre-process to protect the molecular sieve, and the treated compressed air must meet strict purity and dryness standards. The whole process includes three key steps:

• Primary filtration: Large particulate impurities such as dust and pollen in the air are removed by a pre-filter to prevent pipeline blockage and sieve surface contamination.
• Deep purification: A refrigerated dryer combined with a precision filter is used to remove moisture and oil mist from the compressed air—oil and water contamination is the main cause of molecular sieve failure. Trace moisture is further eliminated by an adsorption dryer to ensure the inlet air dew point meets the operational standard.
• Buffer and pressure stabilization: The purified compressed air is stored in an air buffer tank, which balances pressure fluctuations in the system and provides a stable, continuous air supply for the subsequent adsorption tower operation.

1.3 Twin-Tower Alternating Adsorption-Desorption (Core Separation Step)

The system is equipped with two adsorption towers filled with zeolite molecular sieves, and the PLC control system switches the valve state to realize alternating operation of the two towers, ensuring continuous oxygen production. The whole cycle consists of four key stages:

• Adsorption phase: One tower is pressurized to 0.5~1.0MPa. Zeolite molecular sieves have a selective adsorption capacity for impurities such as nitrogen and carbon dioxide, so oxygen molecules penetrate the adsorption bed to form high-purity oxygen (purity ≥90%), which is delivered to the oxygen buffer tank through the gas production valve.
• Pressure equalization phase: The two towers are connected by a pressure equalization valve, and the internal pressure of the two towers tends to balance within 3~5 seconds. This step not only quickly raises the pressure of the standby tower to the working standard but also avoids sudden drops in the system’s output pressure.
• Desorption and regeneration phase: The other tower is depressurized, and the nitrogen adsorbed by the molecular sieve is released to the atmosphere through the exhaust valve. A small amount of high-purity oxygen is used to backflush the tower to remove residual nitrogen, completing the regeneration of the molecular sieve and restoring its adsorption capacity.
• Cycle switching phase: The PLC controller automatically switches the “adsorption-pressure equalization-desorption” working states of the two towers in a fixed cycle, realizing uninterrupted oxygen production of the PSA oxygen generator system.

1.4 Oxygen Output and Pressure/Flow Regulation

The high-purity oxygen stored in the oxygen buffer tank is adjusted to the required working pressure and flow rate by a pressure reducing valve and a flow controller, adapting to different application scenarios. Finally, the oxygen is output through a humidifier for household and medical use, or a filling manifold for industrial oxygen filling and on-site use.

Core process logic: The adsorption and desorption of molecular sieves are controlled by pressure changes in the system; the alternating operation of the two towers guarantees continuous oxygen production; and the multi-stage purification and pretreatment is the key factor to prolong the service life of molecular sieves—the core medium of the whole system.

II. Key Component Maintenance: Details & Fault Consequences (7 Critical Parts)

Each component of the PSA oxygen generator undertakes a unique functional role, and standardized maintenance is the basis for stable system operation. The following table details the core functions, regular maintenance operations, and potential fault consequences of 7 critical components:

Component Name	Core Function	Maintenance Details (Frequency + Operation)	Maintenance Necessity (Fault Consequences)
Air Compressor	The “heart” of the system, supplies stable compressed air for oxygen production	1. Oil-lubricated type: Replace the engine oil and clean the oil filter every 2000~3000 operating hours;2. Oil-free type: Clean the air intake filter screen thoroughly every 3000 operating hours;3. Monitor the exhaust temperature daily (maintain ≤80℃) and check the belt tension regularly for loose or worn belts.	Poor maintenance causes insufficient exhaust pressure and reduced oxygen production efficiency; oil leakage contaminates the compressed air and directly damages the molecular sieve (irreversible damage); excessive exhaust temperature may burn out the compressor motor and cause sudden system shutdown.
Pre-filter / Precision Filter	Removes particulate matter, oil mist and moisture from compressed air	1. Pre-filter: Replace the filter element every 2000~3000 operating hours and monitor the pressure difference (replace immediately if exceeding 0.05MPa);2. Coalescing filter (oil removal): Replace the filter core every 4000~6000 operating hours;3. Manually drain accumulated water weekly, and check the smooth operation of the automatic drain valve regularly.	Filter element blockage leads to insufficient air intake and reduced oxygen output; oil mist and moisture penetrate the filter and cause molecular sieve “poisoning”, resulting in permanent loss of adsorption capacity and extremely high maintenance and replacement costs.
Adsorption Tower (Including Molecular Sieve)	The core medium for oxygen-nitrogen separation, the core component of the system	1. Daily operation: Keep the inlet air temperature ≤15℃ (activate the pre-cooling device in summer) and avoid sudden pressure rises and drops in the tower;2. Annual inspection: Open the manhole to check if the internal bed layer is flat and the screen is damaged or deformed;3. Every 8000~12000 operating hours: Sieve to remove fine molecular sieve powder and replenish new zeolite molecular sieve to the specified height;4. Post long-term shutdown: Activate and regenerate the molecular sieve with dry hot nitrogen at a temperature above 200℃.	Moisture or pollution of molecular sieve causes oxygen purity to drop below 90% (failure of medical-grade oxygen production); bed layer collapse forms “channeling” and interrupts continuous oxygen production; molecular sieve powder enters the pipeline and clogs valves, triggering full system shutdown.
Buffer Tank (Air / Oxygen)	Stabilizes system pressure and temporarily stores compressed air and high-purity oxygen	1. Daily maintenance: Manually drain accumulated water in the tank (increase the drainage frequency in high-humidity environments);2. Every 6 months: Check the sensitivity of the safety valve and test the rated exhaust pressure;3. Annual maintenance: Derust and clean the inner wall of the tank (shorten to 6 months in coastal or humid areas).	Water accumulation in the tank causes internal corrosion and leakage; pressure fluctuations trigger misoperation of system valves; safety valve failure may lead to tank overpressure and explosion; corrosion of the oxygen tank contaminates the high-purity oxygen and affects the safety of industrial and medical use.
Control Valve / Solenoid Valve	The “joints” of the system, switch the working state of the two adsorption towers	1. Every 3 months: Clean the inner cavity of the valve and check if the sealing parts are aged or cracked;2. Every 6 months: Test the valve opening and closing response speed (maintain delay ≤0.5 seconds);3. Routine inspection: Check for air leakage in the pneumatic pipeline connected to the valve regularly.	Valve jamming or air leakage leads to failure of twin-tower switching and direct interruption of oxygen production; aged sealing parts cause system pressure leakage and increase energy consumption by more than 30%; slow valve response damages the pressure equalization process and reduces the purity of produced oxygen.
PLC Control System / Sensor	The “brain” of the system, automatic process control and real-time parameter monitoring	1. Every 6~12 months: Calibrate the oxygen purity sensor and pressure sensor to ensure monitoring accuracy;2. Monthly maintenance: Back up the PLC operating program and clean the heat dissipation port of the control panel to avoid dust accumulation;3. Weekly inspection: Check the responsiveness of the touch screen and clear the fault codes in the system log in a timely manner.	Sensor drift leads to false oxygen purity reporting (e.g., displaying 95% but the actual purity is only 85%); PLC program loss causes complete system paralysis; poor heat dissipation burns out the controller and disables automatic twin-tower switching.
Dryer (Refrigerated / Adsorption Type)	Deep dewatering of compressed air, ensures a dry working environment for molecular sieves	1. Refrigerated dryer: Clean the condenser every 6 months and check the refrigerant pressure to avoid leakage;2. Adsorption dryer: Regenerate the desiccant or replace the desiccant cartridge every 3000 operating hours;3. Daily monitoring: Track the outlet dew point of the dryer (maintain ≤-40℃).	Failure of drying effect leads to excessive moisture in the inlet air and a more than 50% reduction in the adsorption capacity of molecular sieves; refrigerant leakage causes complete dewatering failure and rapid moisture damage to the molecular sieve, resulting in early scrapping.

III. Universal PSA Oxygen Generator Maintenance Principles & Core Benefits

Standardized maintenance is not only to avoid sudden system failure but also to maximize the equipment service life and reduce long-term operation costs. The following summarizes the core maintenance principles and practical benefits of PSA oxygen generators for industrial and medical use.

3.1 3 Core Maintenance Principles (Prevention-Oriented)

The maintenance of PSA oxygen generators follows a prevention-first concept, and all operations are centered on protecting the core components and ensuring stable system operation. The three core principles are:

• Molecular sieve protection as the core: The molecular sieve is the most vulnerable and high-cost component of the PSA oxygen generator, with its replacement cost accounting for 30%~50% of the total equipment price. All maintenance steps (e.g., purification, dewatering, temperature control) are designed to avoid molecular sieve contamination and damage.
• Stable operation to reduce aging: Fluctuations in pressure, temperature and flow rate are the main causes of accelerated component aging. Strictly control the operating parameters within the rated range to avoid sudden changes and reduce the failure rate of valves, sensors and compressors.
• Classified hierarchical maintenance: Formulate a detailed maintenance plan according to the component importance and failure risk: daily/weekly maintenance focuses on simple operations such as water drainage and dust cleaning; monthly/annual maintenance focuses on component replacement, sensor calibration and comprehensive inspection; special activation and regeneration treatment is required for the system after long-term shutdown.

3.2 4 Core Benefits of Standardized Maintenance

Adhering to the above maintenance principles and carrying out regular standardized operations can bring significant long-term benefits for the operation of PSA oxygen generators, covering equipment life, performance, cost and safety:

• Extend overall equipment service life: Standardized maintenance can extend the total service life of the PSA oxygen generator from the original 5 years to 8~10 years, and prolong the service life of the core molecular sieve by more than 50%.
• Ensure stable production performance: Maintain the produced oxygen purity at 90%~96% (the original design value) for a long time, and control the oxygen production fluctuation within ±5% to meet the stable oxygen demand of industrial and medical scenarios.
• Reduce long-term operation costs: Avoid economic losses caused by emergency system shutdown (the hourly shutdown loss of industrial PSA oxygen generators is thousands of yuan); reduce the frequency of replacing high-cost core components such as molecular sieves and air compressors, and lower the daily maintenance and repair costs.
• Meet safety and compliance requirements: Medical PSA oxygen generators must pass GMP certification, and regular maintenance is a necessary condition to ensure oxygen purity up to standard and avoid medical safety risks. Industrial oxygen production also needs to comply with local safety operation standards, and standardized maintenance can eliminate potential safety hazards such as overpressure and leakage.

Following the process flow and maintenance guide in this article can effectively ensure the long-term stable and efficient operation of PSA oxygen generators. For customized PSA oxygen generator solutions and component replacement services, feel free to contact our professional technical team for one-stop support.