The Energy Recovery PX Q260 Pressure Exchanger® is a positive-displacement energy recovery device for seawater reverse osmosis. A single ceramic rotor transfers pressure energy directly from the high-pressure reject stream to the incoming feed, at up to 98% peak efficiency, handling 180 - 260 gpm (40.9-59 m3/h) per device. There is no gearbox, no pistons and no lubricating oil — the rotor is the only moving part.
Documentation & Drawings
Technical Specifications
| Operating Conditions | |
| Service | 3. Reference |
| Liquid | Seawater |
| Flow range | 180 - 260 gpm (40.9-59 m3/h) |
| Maximum high-pressure inlet flow | 260 gpm (59 m3/hr) |
| Maximum low-pressure outlet flow | 260 gpm (59 m3/hr) |
| Maximum inlet high pressure | 1200 psig (82.7 bar) |
| Maximum inlet low pressure | 300 psig (20.7 bar) |
| Minimum discharge pressure | 9 psig (0.6 bar) |
| Operating temperature | 33°F-120°F (0.6-49°C) |
| Maximum temperature | 120°F (49°C) |
| Specific gravity | 1025.18 kg/cu.m |
| Viscosity | 1.060 cP @ 70°F (21.1°C) |
| Filtration requirement (nominal) | 20µm |
| Performance | |
| Peak efficiency | 98% |
| Warranted efficiency | 96.8% |
| Maximum high-pressure differential | 15.7 psig (1.1 bar) @ 260 gpm |
| Maximum low-pressure differential | 11.7 psig (0.8 bar) @ 260 gpm |
| Maximum lubrication flow | 2.5 gpm (0.57 m3/hr) |
| Maximum salinity increase at membranes | 3% @ 40% Recovery |
| Noise per ISO 3744 | Less than 85 dB (A) |
| Materials of Construction | |
| Housing | GRP |
| Rotor, sleeve & endcover assembly | Ceramic-alumina |
| Port fittings | CN3MN |
| Tension rod assembly | AL-6XN* / C-276 |
| Fasteners & hardware (non-wetted) | 316SS |
| O-rings | EPDM |
| Shipping Weight & Dimensions | |
| Cartridge shipping dimensions | 20x12x12 inch |
| Cartridge weight | 65 lbs. (29 kg) |
| Identification | |
| Manufacturer | Energy Recovery, Inc. (San Leandro, CA) |
| Model | PX-Q260 |
| Data sheet reference | ERI 80343-01 |
How the PX Pressure Exchanger Works
A ceramic rotor turns inside a sleeve. Each duct is alternately opened to the high-pressure brine leaving the membranes and to the low-pressure feed entering the system. The high-pressure stream pushes directly against the feed water inside the duct, transferring its pressure with almost no loss; the duct then rotates, the depressurised stream is flushed to drain, and the cycle repeats. Because the transfer is direct hydraulic displacement rather than a mechanical conversion, efficiency is very high and the only moving part is the rotor.
Watch the PX in Operation
Video courtesy of Energy Recovery, Inc.
Where the PX-Q260 Fits
The PX-Q260 is specified on brine (concentrate) flow, not permeate — the pressure exchanger sits on the reject stream. ERI rates it for 180–260 gpm of brine at up to 1,200 psi, at 98% efficiency.
At the 40–45% recovery typical of seawater systems, one unit at full flow supports roughly 249,600–306,327 GPD of permeate (945–1,160 m³/day). That places a single PX-Q260 in resort and hotel complexes, small municipal supply, food and beverage process water, and containerised plants at the larger end of the range.
PX units are installed in parallel arrays, so larger plants simply use more of them — four PX-Q260 units cover about 3,779–4,638 m³/day on the same basis. Below 180 gpm of brine, step down to a smaller model rather than run this one under its minimum.
Capacity figures are indicative, derived from the rated brine flow at typical recovery. Actual output depends on your feed salinity, temperature, membrane configuration and recovery rate — send us your design conditions and we will confirm the model and the number of units.
Frequently Asked Questions
How many PX-Q260 units do I need?
What pre-filtration is required?
Does it need a motor?
What maintenance is involved?
How much energy does it save?
Specifications reproduced from the Energy Recovery technical data sheet for this model. PX® and Pressure Exchanger® are registered trademarks of Energy Recovery, Inc. ERI reserves the right to make specification changes without prior notice; confirm critical values against the current data sheet before purchase.