High-rejection SWRO membranes for desalination plants. 99.5%+ salt rejection. 4040 and 8040 elements. Factory direct.
Get Desalination Quote →Our seawater RO membranes are designed for high-pressure desalination applications, delivering consistent performance in the harshest feed water conditions.
| Flow Rate | 6,000 - 9,000 GPD |
| Salt Rejection | 99.5%+ |
| Operating Pressure | 800 - 1,200 PSI |
| Membrane Type | TFC Polyamide |
| Price (FOB) | $350 - $650 |
Rotating between seawater and brackish specification is the most expensive mistake in this industry. Seawater RO elements are engineered for feed water at 30,000-45,000 ppm TDS and operate somewhere between 800 and 1,200 PSI. Brackish elements are designed for 1,000-10,000 ppm feed at 200-400 PSI, where the osmotic pressure is far lower and the energy cost of pushing water through a denser membrane would be wasted.
Put a brackish element into a seawater duty and salt rejection collapses and the membrane compacts. Put an SWRO element into a brackish duty and you pay for pressure you do not need every hour of the plant's life. The feed analysis, not the plant size, decides which one you buy.
| Feed water | TDS | Operating pressure | Recommended element |
|---|---|---|---|
| Open ocean seawater | 35,000-45,000 ppm | 900-1,200 PSI | Seawater RO 8040 (SWRO) |
| Coastal / estuarine | 15,000-35,000 ppm | 600-900 PSI | Seawater RO or high-pressure brackish |
| Brackish well water | 2,000-10,000 ppm | 200-400 PSI | Brackish RO 8040 / 4040 |
| Low-salinity / process water | Under 2,000 ppm | 150-250 PSI | Brackish RO 4040 |
An 8040 SWRO element produces roughly 6,000-9,000 GPD, about 1.0-1.5 m³/h, at standard test conditions. A 1,000 m³/day plant therefore needs in the region of 30-40 elements arranged in a two-stage array. The array matters as much as the count: a two-stage configuration lets the concentrate from the first stage feed the second, which raises overall recovery from around 35% to 45% without increasing the feed pressure.
Recovery also drives scaling risk. Push past the solubility limit for calcium sulphate or silica and you will be cleaning elements every few weeks. Set your recovery target from the feed analysis and the antiscalant supplier's projection, not from a rule of thumb.
Required pressure rises as feed temperature falls. A plant that runs comfortably at 25°C feed may need 15-20% more pressure at 15°C, so check the pressure envelope of your high-pressure pump against the coldest condition the plant will ever see - not the design average.
Flux is the other control. Running elements above their design flux produces good permeate flow for the first year and then fouls or scales rapidly. Keeping flux within the manufacturer's rated window costs a little more membrane area up front and saves a great deal in cleaning chemicals and early replacement later.
SWRO membranes are built for high salinity feed - typically 30,000-45,000 ppm TDS seawater - and operate at 800-1,200 PSI with 99.5%+ salt rejection. Brackish water membranes handle 1,000-10,000 ppm feed at 200-400 PSI. Using a brackish element on seawater feed will not reach the required rejection, and using an SWRO element on brackish feed wastes energy.
Size by permeate flow. An 8040 SWRO element produces roughly 6,000-9,000 GPD (about 1.0-1.5 m3/h) under standard test conditions. A 1,000 m3/day plant therefore needs about 30-40 elements arranged in a two-stage array, typically 6-8 pressure vessels per stage depending on recovery target.
800-1,200 PSI (55-83 bar) for standard seawater. As feed temperature drops the required pressure rises, so a plant running at 15°C feed needs more pressure than the same plant at 25°C. Always check the pressure envelope of your high-pressure pump against the coldest feed condition.
Two to three years in a well-run plant, sometimes longer with good pre-treatment. The main enemies are scaling from calcium carbonate and sulphate, biofouling, and oxidation from residual chlorine. Effective pre-treatment - media filtration, antiscalant dosing, and dechlorination - is what determines whether you replace elements every other year or every year.
At minimum multimedia or ultrafiltration pre-treatment, antiscalant dosing, and dechlorination before the membranes. If your source has high organic loading, add coagulation and a further fine filtration stage. Pre-treatment failures are the single most common cause of premature element failure in desalination.
Yes. Our 4040 and 8040 elements use standard nominal dimensions and end connections, so they drop into major-brand pressure vessels and interconnectors without modification.
Bulk pricing available for desalination plants and water treatment companies.
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