As a professional manufacturer supplying full-range industrial water treatment solutions centered on Liquid Filters, we provide mature seawater reverse osmosis spiral wound elements for island freshwater supply, coastal municipal desalination plants and offshore industrial water production. The SW30XHR-400i is an 8-inch seawater RO membrane belonging to the classic SW30 seawater series, developed for large-scale high-standard desalination projects that require ultra-low TDS permeate. Positioned as a high-performance import substitution model, it delivers stable ultra-high salt rejection while maintaining controlled overall project input cost, serving as a cost-effective mid-to-high-end solution for coastal desalination engineering.
As a professional manufacturer supplying full-range industrial water treatment solutions centered on Liquid Filters, we provide mature seawater reverse osmosis spiral wound elements for island freshwater supply, coastal municipal desalination plants and offshore industrial water production. The SW30XHR-400i is an 8-inch seawater RO membrane belonging to the classic SW30 seawater series, developed for large-scale high-standard desalination projects that require ultra-low TDS permeate. Positioned as a high-performance import substitution model, it delivers stable ultra-high salt rejection while maintaining controlled overall project input cost, serving as a cost-effective mid-to-high-end solution for coastal desalination engineering.
Designed with a standard 8-inch universal dimension, this spiral wound RO membrane matches all mainstream high-pressure seawater pressure vessels on the market. It supports direct replacement of aged 8-inch seawater RO elements without extensive pipeline or high-pressure pump reconstruction, effectively cutting equipment renovation investment for existing desalination stations. Optimized polyamide separation layer and wide streamline feed spacers are adopted to balance interception efficiency and anti-fouling performance, forming stable long-cycle operation performance suitable for conventional coastal seawater intake water quality.
Separation inside SW30XHR-400i follows the standard solution-diffusion mechanism of reverse osmosis, rather than simple physical pore screening. Water molecules dissolve into the dense cross-linked polyamide active layer and diffuse through the membrane matrix to form fresh permeate, while soluble salt ions in seawater are repelled by the membrane surface via Donnan exclusion effect to achieve reliable salt interception.
Compared with conventional standard seawater RO elements, SW30XHR-400i optimizes the compactness and uniform surface charge density of the polyamide separation layer. Tighter molecular arrangement further restricts penetration of tiny hydrated salt ions, lifting stabilized salt rejection under standard test conditions. The widened internal feed spacer suppresses local concentration polarization during long-term high-pressure operation, slowing performance attenuation caused by accumulated fouling. The smooth hydrophilic membrane surface reduces adhesion of marine algae, suspended solids and organic colloids, sustaining consistent interception capacity under 24-hour continuous operation. Different from low-pressure brackish water industrial RO membrane, this seawater-specific element is structurally reinforced to withstand the high operating pressure required for raw seawater desalination, matching the high-salinity characteristics of coastal seawater perfectly.
| Item | Standard Parameter |
|---|---|
| Model | SW30XHR-400i |
| Structure | 8-inch spiral wound seawater RO membrane |
| Effective Membrane Area | 400 sq. ft |
| Standard Test Condition | 25°C, 800 psi, 32000 ppm NaCl simulated seawater |
| Stabilized Salt Rejection (Standard Test) | ≥99.80% |
| Rated Permeate Flow Rate | 8400–9700 GPD |
| Continuous Operating Pressure Range | 650–900 psi |
| Long-Term Operating pH | 2.0–10.5 |
| Chemical Cleaning pH Range | 1.0–12.5 |
| Maximum Allowable Feed SDI | ≤4 |
| Single Element Pressure Drop | ≤16 psig |
Within feed water TDS ≤ 38,000 mg/L and operating temperature 15°C–30°C, the actual stabilized salt rejection of SW30XHR-400i shall not be lower than 99.70%.
1.Permeate flux and salt rejection shift with temperature: permeate yield drops roughly 3% per 1°C temperature reduction, and salt rejection slightly declines at elevated temperatures. Temperature correction factors must be referenced for accurate engineering design calculation.
2.The 99.80% ultra-high salt rejection index only applies to standard test water quality. When raw seawater salinity exceeds test benchmark, actual permeate salinity needs recalculation via professional design software.
3.Value conversion of ultra-high salt rejection: The 0.05% promotion of salt rejection reduces permeate TDS from about 80 ppm to 64 ppm under the same feed water condition. For large-scale municipal desalination plants with daily water output above 10,000 tons, lower permeate salinity can reduce the dosage of post-treatment ion exchange resin by around 12%, cutting monthly chemical consumption and waste regeneration costs.
Complete official datasheets cover pressure resistance, temperature adaptability, marine fouling simulation and cleaning recovery test data, providing full parameter support for seawater desalination system design.
The core competitiveness of SW30XHR-400i is fully demonstrated by verified ultra-high salt rejection test indicators and comprehensive long-cycle operation benefits. Its stabilized salt rejection rate above 99.80% under standard test conditions suppresses permeate TDS to an extremely low level, reducing the load and sizing of downstream post-treatment polishing equipment for most drinking water projects and lowering auxiliary equipment procurement and daily chemical operation costs. The expanded 400 sq. ft membrane area delivers higher single-element permeate output, cutting the total number of membrane elements and supporting pressure vessels required for large desalination plants to reduce upfront equipment investment.
The optimized wide flow channel structure slows marine pollutant accumulation on the membrane surface. Comparative fouling simulation tests show its effective cleaning cycle is 15–20 days longer than ordinary high-rejection seawater membranes, lowering labor and cleaning agent consumption for routine maintenance. The universal 8-inch seawater membrane size enables seamless replacement of outdated low-performance elements on existing desalination lines; only minor pressure adjustment is required after replacement to restore standard ultra-high salt rejection performance.
When operated strictly in line with recommended pretreatment standards (feed SDI ≤4), complete free chlorine neutralization and standardized periodic cleaning plans, the membrane maintains stable interception performance and extends overall RO membrane lifespan, delaying full membrane replacement cycles to control long-term project operating expenditure.
Supported by ultra-high salt rejection and stable long-cycle anti-fouling performance, SW30XHR-400i is widely adopted in medium and large seawater desalination projects with strict low-salinity freshwater requirements. It serves as the core filtration component for coastal municipal large-scale desalination plants, steadily producing drinking water that meets international salinity standards and lowering post-treatment equipment load. Offshore island permanent residential freshwater supply systems and marine oil platform industrial water production units adopt this 8-inch large-area membrane to realize continuous large-volume water production; its mature universal specification simplifies spare parts stocking and daily maintenance work for remote offshore facilities. Coastal high-end resort clusters, marine aquaculture industrial parks and port service stations deploy SW30XHR-400i to build low-maintenance desalination systems and secure consistent qualified freshwater supply all year round. In industrial seawater desalination for power plant cooling water and factory process water supply, engineering designers reference complete salt rejection data, temperature correction coefficients and post-treatment cost conversion values to calculate membrane quantity and high-pressure pump configuration accurately, optimizing system layout while complying with environmental protection and water quality supervision standards.
Every batch of SW30XHR-400i membrane elements undergoes full sampling high-pressure simulated seawater testing before delivery, with unique serial-numbered inspection documents recording complete salt rejection, permeate flow rate and pressure resistance data. The whole production workflow complies with ISO 9001 quality management systems; all wetted raw materials meet international drinking water safety criteria, and core interception indicators pass third-party seawater desalination performance certification. Complete technical datasheets with temperature correction curves, batch test records and material traceability documents are supplied alongside goods for engineering design reference, tender filing and factory acceptance audits. Finished membranes are vacuum-sealed with specialized anti-desiccation protective liquid to prevent separation layer damage during transit and storage, ensuring on-site installed performance matches official reference test values under qualified pretreatment and temperature operating limits.
Coastal urban expansion and remote island resource development keep driving steady market demand for high-performance seawater desalination membranes. Ultra-high rejection customized imported seawater membranes carry excessively high unit procurement costs, while conventional standard seawater RO elements cannot satisfy the ultra-low permeate TDS requirements of high-standard municipal and industrial projects. As a cost-effective import substitution solution, SW30XHR-400i fills the mid-to-high-end market gap, balancing ultra-high salt rejection and controllable full-cycle operation cost.
Our R&D team will continue refining the hydrophilic polyamide separation layer formula of SW30XHR-400i to further stabilize salt rejection indexes and strengthen marine anti-fouling characteristics, extending the window of consistent stable performance. Its universal matching size and low maintenance cost align with global trends toward compact, energy-saving desalination infrastructure, supporting wider adoption in new coastal desalination plant construction and energy-saving retrofits of legacy seawater treatment stations.
SW30XHR-400i, the classic 8-inch seawater RO membrane for seawater desalination, takes certified ultra-high salt rejection performance as its core technical benchmark, designed to address the demand for ultra-low TDS permeate in medium and large coastal desalination projects. Via dense optimized polyamide separation layer and wide anti-fouling feed spacer design, it achieves stabilized salt rejection above 99.80% under standard test conditions, effectively reducing the sizing and operation cost of downstream post-treatment equipment.
Compared with conventional standard high-rejection seawater membrane products, SW30XHR-400i delivers measurable economic benefits through higher single-element water yield and extended cleaning intervals, bringing long-term cost-saving returns to desalination project operators. For seawater treatment design engineers, desalination equipment manufacturers and coastal water station operators pursuing consistent ultra-low salinity freshwater output, SW30XHR-400i high-performance seawater RO element is a reliable import-substitution economical solution.
Q1: What is the product positioning difference between SW30XHR-400i and other models within the SW30 series?
A1: The SW30 classic seawater series covers full specifications to match differentiated project demands. SW30-2540 is a compact 2.5-inch model for small experimental and miniature modular desalination units; SW30HR-380 is an economical high-rejection model for conventional coastal desalination projects with general water quality requirements; SW30XHR-400i is a high-performance import substitution model for large-scale high-standard projects requiring ultra-low permeate salinity. Customers can select corresponding models according to project scale, water quality and freshwater index requirements.
Q2: Can SW30XHR-400i directly replace other 8-inch seawater membrane elements on existing desalination equipment?
A2: Yes. It adopts universal 8-inch seawater membrane dimensions compatible with all mainstream high-pressure seawater pressure vessels. Minor operating pressure adjustments are required after replacement, and temperature correction factors should be applied for accurate long-term performance forecasting.
Q3: How long can SW30XHR-400i maintain its ultra-high salt rejection performance?
A3: Performance stability and service life depend entirely on strict adherence to recommended pretreatment (feed SDI ≤4), complete free chlorine removal and scheduled standardized acid-alkali cleaning cycles. When all operation and maintenance specifications are fully followed, the membrane can sustain certified salt rejection indicators within the guaranteed range for 3–5 years of continuous service; inadequate pretreatment or irregular cleaning will accelerate performance attenuation.
Q4: What pretreatment equipment is required to maintain stable ultra-high salt rejection performance?
A4: A full pretreatment train including multimedia filtration, cartridge filtration and 5μm security filters is mandatory to limit feed water SDI below 4. Free chlorine must be fully neutralized prior to the membrane to avoid irreversible oxidation damage to the polyamide layer, which would permanently degrade salt rejection efficiency.
Q5: Is SW30XHR-400i suitable for brackish water desalination projects?
A5: This model is purpose-built for high-salinity raw seawater desalination with high pressure resistance. For conventional tap water and low-salinity brackish water treatment, our dedicated brackish water RO membrane series is recommended for superior cost-performance.
RO Membrane for Drinking Water 99.2% Desalination Rate
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