Significant pressure fluctuations during the operation of reverse osmosis pure water equipment directly impact product water quality, equipment energy consumption, and membrane element lifespan, requiring a comprehensive system-wide analysis and resolution. Pressure fluctuations are typically caused by a combination of external factors and internal faults, necessitating a layered troubleshooting and item-by-item verification approach to pinpoint the root cause.
External power supply stability is the primary area to investigate. Voltage fluctuations directly lead to unstable high-pressure pump speeds, resulting in periodic changes in system pressure. For example, sudden changes in grid load or aging power supply lines can cause a momentary drop in input voltage, leading to insufficient output pressure from the high-pressure pump; conversely, when the voltage recovers, the pump may experience a brief period of high pressure due to overload. Such issues require the installation of a voltage stabilizer or inspection of power supply line contact points. It is also recommended to configure a UPS (Uninterruptible Power Supply) to handle the risk of sudden power outages.
Abnormalities in the water supply system are a common cause of pressure fluctuations. Insufficient raw water supply or pipeline design defects can lead to unstable inlet water flow, thereby affecting the inlet pressure of the high-pressure pump. For example, a low raw water tank level, an inlet valve not fully open, or a blocked or bent pipe can all cause a sudden drop in inlet water pressure. Improper pump selection or insufficient head will prevent the water supply pressure from meeting system requirements. Furthermore, a clogged inlet filter significantly increases flow resistance, causing drastic pressure fluctuations before and after the filter. Solving these problems requires inspecting the raw water supply system, cleaning the pipes and filters, and ensuring the pump parameters are compatible with the equipment.
The high-pressure pump, as the core power source of the system, directly affects pressure stability. Aging pump body seals, impeller wear, or bearing damage can lead to internal leakage, preventing the output pressure from maintaining the set value. Insufficient pump inlet pressure or air intake can cause cavitation, resulting in drastic pressure fluctuations. For example, when the inlet water pressure is lower than the pump's minimum requirement, air will enter the pump chamber, forming bubbles. The impact force generated when these bubbles burst can damage the pump's internal structure and cause intermittent pressure. Such faults need to be repaired by checking the pump's sealing, replacing worn parts, and ensuring the inlet water pressure meets the requirements.
The condition of precision filters and membrane elements has an amplifying effect on pressure fluctuations. Clogged precision filter cartridges significantly increase water flow resistance, creating a pressure difference across the system. Scale or fouling on membrane elements alters pore permeability, leading to decreased permeate flow and consequently increased system pressure. For example, when membrane elements are contaminated with inorganic salts, microorganisms, or organic matter, both desalination rate and permeate flow decrease simultaneously. To maintain permeate flow, the system automatically increases inlet pressure, creating a vicious cycle. Solving these problems requires regular filter cartridge replacement and chemical or physical cleaning of the membrane elements.
System piping design flaws or valve malfunctions are also significant causes of pressure fluctuations. Bends, narrowing, or improper layout in the piping can increase localized flow resistance, resulting in pressure loss. Jammed or improperly adjusted critical valves, such as concentrate regulating valves and inlet pressure regulating valves, can directly disrupt system pressure balance. For instance, an excessively small opening in the concentrate regulating valve can hinder concentrate discharge, increasing inlet pressure to the membrane element. A malfunctioning inlet pressure regulating valve may prevent the system pressure from automatically adjusting to the inlet water quality. These issues require optimizing the piping design and checking and calibrating all valves.
Faults in control instruments and automation systems can mask true pressure fluctuations. Decreased pressure sensor accuracy or abnormal signal transmission can cause discrepancies between displayed and actual values, leading operators to misjudge the system status. Incorrect PLC control system parameter settings or program logic defects can cause lag or erratic movements in actuators such as high-pressure pumps and valves. For example, when a pressure sensor range drifts, the system may mistakenly interpret the pressure as too high and reduce the high-pressure pump speed, while the actual pressure continues to drop due to insufficient water intake. Solving such problems requires regular instrument calibration and checking the control system program and parameter settings.
Pressure fluctuation problems in reverse osmosis pure water equipment require systematic troubleshooting, encompassing multiple aspects such as power supply, water supply, pumps, filtration, piping, and control systems. Operators should establish a regular maintenance system, recording trends in key parameters such as pressure and flow rate, and combining this information with equipment operation logs and historical fault records to quickly pinpoint the root cause of the problem. Simultaneously, it is recommended to configure pressure buffer devices or intelligent pressure regulating systems to enhance the equipment's adaptability to pressure fluctuations and ensure long-term stable operation.
