The Danfoss iSave 50 (code 180F7020) is a seawater reverse-osmosis energy recovery device supplied as a bare unit without an electric motor, combining a rotary pressure exchanger and a booster pump in one assembly. Specify your own motor, coupling and base frame, or ask us for the matching motorised build.
Documentation & Drawings
Technical Specifications
| This Configuration | |
| Code number | 180F7020 |
| Model | iSave 50 |
| Motor | Not included — bare device |
| Performance | |
| Flow at min. speed, HP out | 42 m³/h (184 gpm) |
| Flow at max. speed, HP out | 52 m³/h (228 gpm) |
| Max. allowable working flow, LP in | 57.2 m³/h (252 gpm) |
| Peak flow, LP in | 120 m³/h (528 gpm) |
| Max. lubrication flow at 60 barg (871 psig) | 25 l/min (6.6 gpm) |
| Speed range | 525 – 650 rpm |
| Max. pressure HP out (MAWP) | 83 barg (1200 psig) |
| Min. pressure HP out | 40 barg (580 psig) |
| Max. differential pressure (HP out − HP in) | 5 barg (72 psig) |
| Min. pressure HP in, intermittent | 2 barg (29 psig) |
| Max. pressure LP in (MAWP) | 5 barg (72 psig) |
| Max. pressure LP in, peak | 10 barg (145 psig) |
| Min. allowable working pressure LP in | 2 barg (29 psig) |
| Differential pressure at max. flow (LP in − LP out) | 0.53 barg (7.69 psig) |
| Max. static test pressure (HP in / HP out) | 108 barg (1566 psig) |
| Max. static test pressure (LP in / LP out) | 13 barg (189 psig) |
| Max. allowable working torque | 170 Nm (125 lbf-ft) |
| Max. starting torque (stick/slip) | 180 Nm (132 lbf-ft) |
| Operating Conditions | |
| Media temperature | 2 – 35°C (36 – 95°F) |
| Ambient temperature | 0 – 50°C (32 – 122°F) |
| Filtration requirement (nominal) | 5 micron melt-blown |
| Salinity increase at membrane (40% recovery) | 2 – 3% |
| Sound pressure level LPA at 1 m | 83 dB(A) |
| Weight & Footprint | |
| Weight (dry) | 164 kg (362 lb) |
| Weight (operation with water) | 172 kg (379 lb) |
| Identification | |
| Manufacturer | Danfoss High Pressure Pumps |
| Data sheet reference | Danfoss AI264763692435en-000904, §8.1 |
Videos
Optimizing SWRO energy use with Danfoss pumps and iSave ERD selection tools
Understanding SWRO energy use — how to cut it with Danfoss pumps and ERDs
Videos courtesy of Danfoss High Pressure Pumps.
Case Studies
Real installations using Danfoss pumps and iSave energy recovery:
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How the iSave Works
The iSave combines a rotary pressure exchanger, which transfers pressure energy directly from the high-pressure reject brine to the incoming low-pressure feed, with a booster pump that makes up the small pressure differential across the exchanger. Because the energy transfer is direct hydraulic displacement rather than a mechanical conversion, the high-pressure feed pump only has to supply the permeate flow.
The iSave 50 delivers up to 52 m³/h (228 gpm) at the high-pressure outlet. All wetted parts are made of high corrosion-resistant materials including Super Duplex stainless steel, and there is no high-pressure mechanical seal and no need for high-pressure flow meters.
Frequently Asked Questions
How do I size the iSave 50 for my plant?
What pre-filtration does it need?
What else do I need to order with this?
Does it need a VFD?
How is it shipped?
Specifications reproduced from Danfoss data sheet AI264763692435en-000904. iSave® is a registered trademark of Danfoss A/S. Danfoss reserves the right to alter specifications without notice; confirm critical values against the current data sheet before purchase.
