This acid and alkali resistant PP wound filter cartridge is a high-performance industrial filtration component specially engineered for the removal of suspended solids in municipal water supply and secondary water supply systems, designed to adapt to the slight pH fluctuations and complex water quality characteristics of urban water supply networks. Crafted from high-purity, modified acid and alkali resistant polypropylene (PP) resin as the core raw material, it is manufactured via a high-precision spiral winding process on a reinforced rigid PP inner support core, with an adhesive-free integral forming process. The cartridge forms a three-dimensional graded porous filtration structure with excellent chemical stability, which can efficiently intercept various suspended solid impurities in municipal and secondary water supply while withstanding the acid-base water quality changes in the water supply network caused by pipeline aging, disinfection and water source adjustment. It is compatible with standard 10/20/30/40-inch filter housings widely used in urban water supply systems, features strong structural stability, easy installation and replacement, and contains no toxic additives, ensuring no secondary pollution to the water body. As a key filtration component for urban water supply purification, it effectively improves the turbidity and cleanliness of terminal water, protecting the urban water supply pipeline system and terminal water use equipment.

Targeted at the suspended solid impurity characteristics of municipal water supply and secondary water supply, the filtration precision of this acid and alkali resistant PP wound filter cartridge is available in urban water supply industry mainstream specifications of 5 μm, 10 μm, 20 μm, 30 μm and 50 μm, with 10 μm and 20 μm being the most commonly used standard specifications for daily water supply filtration. This precision range is scientifically designed to intercept the main suspended solid impurities in urban water supply, including silt, clay particles, rust residues from pipeline corrosion, suspended colloids, sand grains and tiny particulate impurities introduced during water transportation and secondary water supply storage. The graded winding design ensures uniform and stable filtration precision across the entire cartridge body, realizing efficient and targeted interception of suspended solids of different particle sizes without excessive flux loss, and perfectly matching the filtration demands of municipal water supply networks with different water quality conditions and secondary water supply facilities such as water tanks and water towers.

Under the standard urban water supply operating conditions of 25℃ ambient temperature and 0.2MPa inlet pressure, the nominal flux of this acid and alkali resistant PP wound filter cartridge is precisely matched to its specification to meet the diverse water flow demands of municipal and secondary water supply: the 10-inch model reaches 8-15 L/min, 20-inch model 15-25 L/min, 30-inch model 30-45 L/min and 40-inch model 60-80 L/min. For the same specification, the flux is slightly adjusted based on filtration precision: the 5 μm and 10 μm high-precision models have a slightly lower flux, while the 20 μm, 30 μm and 50 μm models feature a higher and more stable flux. The large-flux design is fully adapted to the high water supply demand of municipal water supply networks and secondary water supply systems for residential quarters, commercial areas and public facilities, ensuring continuous and stable water supply for urban water use while maintaining efficient suspended solid removal efficiency, and avoiding the problem of insufficient water output in the water supply system caused by low filter cartridge flux.

As a physical filtration component dedicated to suspended solid removal in municipal water supply and secondary water supply systems, this acid and alkali resistant PP wound filter cartridge is designed only for particle size-based interception of insoluble solid impurities, and has no ion separation, desalination or salt rejection functionality. Therefore, it has no salt rejection rate index. All dissolved inorganic salts, mineral ions, small molecule soluble substances and disinfection by-products in the water supply can pass through the cartridge body smoothly, which is consistent with the core demand of urban water supply filtration—removing harmful suspended solids without changing the basic mineral composition and ion content of tap water, and ensuring that the terminal tap water complies with national drinking water quality standards for mineral components.

The initial pressure drop of a new acid and alkali resistant PP wound filter cartridge under the standard nominal flux and 25℃ operating temperature is ≤0.03MPa for all specifications, which is far lower than the pressure drop limit of municipal water supply and secondary water supply systems, ensuring minimal pressure loss of the water body in the filtration link and reducing the energy consumption of water supply pumps and secondary water supply booster pumps. With the continuous operation of the water supply system, as suspended solid impurities are continuously intercepted and accumulated on the surface and inside of the cartridge body, the pressure drop will gradually rise. The recommended maximum operating pressure drop of this cartridge is 0.15MPa for all specifications; when the pressure drop reaches this value, the cartridge must be cleaned or replaced in time to avoid excessive pressure loss in the water supply pipeline, which will lead to reduced water pressure at the terminal, increased energy consumption of booster equipment, and even blockage of the filter cartridge caused by excessive impurity accumulation.

This acid and alkali resistant PP wound filter cartridge adopts a pure physical filtration mechanism based on particle size interception, which is fundamentally different from membrane filtration components such as ultrafiltration, nanofiltration and reverse osmosis that separate substances according to molecular weight and molecular size. Therefore, it has no specific Molecular Weight Cutoff (MWCO) index. Its interception effect is only aimed at insoluble suspended solid impurities with particle sizes larger than its set filtration precision; macromolecular organic substances, soluble colloids and other dissolved substances in municipal water supply and secondary water supply can pass through the cartridge body as long as their actual particle size is smaller than the filtration precision. This design fully meets the filtration demand of urban water supply systems that only need to remove insoluble suspended solids without separating dissolved macromolecular substances.

The effective acid and alkali resistant PP filtration layer thickness of this filter cartridge is optimized according to its specification and the actual demand of urban water supply filtration, with the 10-inch model at 6-9mm, 20-inch model at 9-13mm, 30-inch model at 11-16mm and 40-inch model at 13-19mm. The total outer diameter of all specifications is the industry standard 63mm/70mm, perfectly matching the internal size of standard filter housings for municipal water supply and secondary water supply systems. The thickened effective filtration layer, customized for each specification, not only ensures a large impurity holding capacity to effectively delay the rise of pressure drop and reduce the frequency of cleaning and replacement, but also forms a multi-layer stepped filtration structure to intercept suspended solids of different particle sizes step by step, improving the overall filtration efficiency and suspended solid removal rate of the cartridge. The inner support core is made of reinforced rigid PP material with a thickness of 3-5mm (matching the specification), which has excellent pressure resistance and structural stability, and will not deform or rupture under the operating pressure of 0.6MPa, fully adapting to the pressure fluctuation characteristics of municipal water supply networks and secondary water supply booster systems during operation.

The recommended replacement cycle of this acid and alkali resistant PP wound filter cartridge is determined by its specification and the actual water quality of municipal and secondary water supply: for 10/20-inch models used in residential quarter secondary water supply facilities (water tanks, booster pumps) and small public facility water supply systems, the standard replacement cycle is 2-4 months; for 30/40-inch models applied in municipal water supply network branch pipelines, large commercial complex secondary water supply systems and public utility water supply systems (schools, hospitals, parks), the standard cycle is 3-6 months. The actual replacement cycle is closely related to the suspended solid content and turbidity of the water supply: for water supply with high turbidity (NTU＞8) and serious pipeline rust (such as old urban area water supply networks), the cycle is shortened by 1-2 months; for water supply with low turbidity (NTU＜4) and well-maintained pipelines (new urban area water supply networks), the cycle can be appropriately extended. In addition, regular backwashing with clean tap water can remove most surface accumulated impurities, and appropriately extend the replacement cycle of the cartridge by 1 month under the premise of ensuring filtration efficiency. Once the system pressure drop reaches 0.15MPa, the cartridge must be replaced immediately regardless of the actual use time to ensure the normal operation of the water supply system.

This acid and alkali resistant PP wound filter cartridge has a number of professional performance features adapted to the complex water quality and operating characteristics of municipal water supply and secondary water supply systems: 1. Modified acid and alkali resistant PP raw material: Adopts high-purity modified polypropylene resin with excellent chemical stability, resistant to acid and alkali corrosion in the pH value range of 1-14, adapting to the slight pH fluctuations of municipal water supply caused by disinfection, pipeline aging and water source adjustment, with long service life in complex water quality environments; 2. Adhesive-free integral winding forming: No adhesives, binders or glues are used in the entire production process, avoiding the dissolution of harmful organic substances into the water body and secondary pollution of urban water supply, while ensuring the structural firmness of the cartridge and no delamination or cracking during long-term operation; 3. High suspended solid removal efficiency: Graded three-dimensional porous filtration structure and uniform winding precision realize efficient interception of suspended solids of different particle sizes, with a suspended solid removal rate of more than 95% for impurities larger than the set filtration precision, effectively improving the cleanliness of terminal tap water; 4. Reinforced pressure-resistant structure: Reinforced rigid PP inner support core with excellent pressure resistance, can withstand 0.6MPa operating pressure and pressure fluctuations in the water supply network, no deformation or rupture, adapting to the working environment of municipal water supply and secondary water supply booster systems; 5. Large impurity holding capacity: Thickened effective filtration layer and multi-layer stepped filtration structure realize large-capacity impurity storage, effectively delaying the rise of pressure drop and reducing the frequency of cleaning and replacement, saving the operation and maintenance costs of urban water supply systems; 6. Low initial pressure drop with stable flux: Optimized internal flow channel design and high-precision winding process ensure ultra-low initial pressure drop and stable flux during long-term operation, reducing the energy consumption of water supply pumps and booster pumps, and ensuring continuous and stable water supply for urban water use; 7. Standard compatibility & easy maintenance: Matches all industry standard 10/20/30/40-inch filter housings (PP plastic/304 stainless steel), with unified installation specifications, easy disassembly and replacement, no need for professional tools, and supports physical backwashing, suitable for large-scale promotion and application in municipal water supply systems; 8. Environmental protection & non-toxic: The whole cartridge is made of food-grade and industrial-grade dual-standard PP material, free of heavy metals, plasticizers and toxic additives, complying with national drinking water quality standards, and the discarded cartridge can be recycled, in line with the green environmental protection requirements of urban water supply construction.

This acid and alkali resistant PP wound filter cartridge is a dedicated filtration component for suspended solid removal in municipal water supply and secondary water supply systems, and its core application fields cover all urban water supply scenarios with complex water quality and the need for efficient suspended solid removal: 1. Municipal water supply network filtration: Applied to the filtration of municipal tap water supply network branch pipelines and main pipeline secondary filtration, removing suspended solids generated during long-distance water transportation, and improving the water quality of the water supply network in different urban areas; 2. Residential quarter secondary water supply: Installed in the filtration link of secondary water supply facilities (water tanks, water towers, booster pump rooms) of residential quarters, especially old urban residential areas, removing suspended solids such as rust and sediment generated in water storage and transportation, and ensuring the cleanliness of tap water in residents’ homes; 3. Commercial complex water supply: Used in the secondary water supply and purification systems of shopping malls, office buildings, hotels and high-rise buildings, adapting to the high water supply demand of commercial areas and improving the water quality of commercial water use and domestic water; 4. Public facility water supply: Applied to the water supply filtration systems of schools, hospitals, parks, stadiums and municipal administrative buildings, ensuring the safety and cleanliness of tap water for public places with large water use and dense personnel; 5. Industrial and mining area supporting water supply: Used in the municipal water supply filtration systems of industrial and mining areas and development zones, adapting to the slight acid-base water quality changes in the water supply of industrial and mining areas, and removing suspended solids to protect the production and domestic water use equipment of enterprises; 6. Urban water supply station filtration: Installed in the outlet filtration link of municipal water supply plants and secondary water supply stations, as the final filtration step of tap water production, further reducing the turbidity of tap water and ensuring that the water supply complies with national drinking water quality standards; 7. Pipeline network renovation supporting filtration: As a key supporting filtration component for urban water supply pipeline network renovation and old community transformation projects, it effectively solves the problem of terminal water quality deterioration caused by pipeline corrosion and rust in old urban areas.

In summary, this acid and alkali resistant PP wound filter cartridge is a high-performance, professional filtration component specially developed for the removal of suspended solids in municipal water supply and secondary water supply systems, and is an indispensable core filtration product for improving urban water supply quality and optimizing the operation of water supply systems. Its design is fully tailored to the complex water quality characteristics and operating demands of urban water supply networks: adopting modified acid and alkali resistant PP raw materials with excellent chemical stability, it can withstand the wide range of pH fluctuations in municipal water supply, effectively solving the problem of filter cartridge aging and failure caused by complex water quality. The graded three-dimensional filtration structure with 5-50 μm precision efficiently intercepts various suspended solid impurities in water supply, significantly reducing the turbidity of tap water, improving the cleanliness of terminal water, and avoiding pipeline blockage and terminal water use equipment damage caused by suspended solids. With the advantages of low initial pressure drop, large flux, large impurity holding capacity and reinforced pressure resistance, it adapts to the high water supply demand and pressure fluctuation characteristics of municipal and secondary water supply systems, reducing the energy consumption of water supply equipment and the operation and maintenance costs of the water supply system. The adhesive-free integral forming process and non-toxic PP material ensure no secondary pollution to the water body, complying with national drinking water quality standards. It is widely compatible with standard filter housings of various specifications, easy to install and maintain, and suitable for large-scale promotion and application in urban water supply construction, pipeline network renovation and old community transformation projects. As a dedicated filtration component for urban water supply, it plays a key role in improving the quality of urban tap water, protecting the urban water supply pipeline system and enhancing residents’ water use experience, and is the first choice for suspended solid removal in municipal water supply and secondary water supply systems.

The matching related products of this acid and alkali resistant PP wound filter cartridge are all core components and supporting equipment of municipal water supply and secondary water supply purification systems, forming a complete urban water supply filtration product system adapted to complex water quality: 1. Acid and alkali resistant melt-blown PP filter cartridges: Acid and alkali resistant melt-blown PP filter cartridges of 10/20/30/40-inch specifications, an alternative filtration component for this wound filter cartridge, with a more compact filtration structure, suitable for municipal water supply with high fine suspended solid content; 2. Standard urban water supply filter housings: 10/20/30/40-inch filter housings made of acid and alkali resistant PP plastic and 304/316 stainless steel, the special supporting equipment for this filter cartridge, with single/multi-core specifications, adapting to the different water flow demands of municipal and secondary water supply systems; 3. Water supply booster and pressure stabilizing equipment: Including booster pumps, pressure stabilizing tanks and frequency conversion water supply equipment matching with urban secondary water supply systems, used with this filter cartridge to ensure stable water pressure and continuous water supply in the water supply system; 4. Backwashing and cleaning equipment: Including high-pressure backwash pumps, backwash pipelines and filter cartridge cleaning tanks, used for the physical backwashing of this filter cartridge, removing surface accumulated impurities and extending the service life of the cartridge; 5. Water quality monitoring instruments for urban water supply: Including turbidity meters, pH meters, suspended solid detectors and pressure gauges specially used for urban water supply systems, real-time monitoring of water supply quality and the operating status of the filter cartridge, facilitating timely maintenance and replacement; 6. Pipeline anti-corrosion and filtration accessories: Including acid and alkali resistant silicone gaskets, stainless steel quick connectors, Y-type pre-filters and check valves for water supply pipelines, used for the installation, sealing and primary coarse filtration of this filter cartridge and filter housings, protecting the filtration system and water supply pipelines; 7. Same series PP wound filter cartridges: The conventional food-grade and high-flow PP wound filter cartridges of the same specifications, which can be replaced and used according to the different water quality requirements of urban water supply sub-regions, forming a diversified filtration product system; 8. Urban water supply pre-treatment equipment: Including multi-media filters, quartz sand filters and activated carbon filters used in municipal water supply plants and secondary water supply stations, matching with this filter cartridge to form a multi-stage filtration system, further improving the purification effect of urban water supply and reducing the filtration load of the filter cartridge.