The Danfoss iSave 40 (code 180F7004) is a complete seawater reverse-osmosis energy recovery unit supplied on a horizontal base frame with a IEC 180 L 15 kW (20 HP), 6-pole motor. It combines a rotary pressure exchanger and a booster pump in one assembly, recovering pressure energy from the membrane reject stream and returning it to the feed — typically cutting SWRO energy consumption by around 60% against a system with no energy recovery.
Documentation & Drawings
Technical Specifications
| This Configuration | |
| Code number | 180F7004 |
| Model | iSave 40 — horizontal base frame |
| Motor | IEC 180 L, 15 kW (20 HP), 6-pole |
| Alternative orientation | 180F7005 (vertical) |
| Performance | |
| Geometric displacement | 626 cm³/rev (38.2 in³/rev) |
| HP outlet flow range at max. differential pressure | 21 – 41 m³/h (92 – 180.5 gpm) |
| LP inlet max. flow | 67 m³/h (295 gpm) |
| Lubrication flow at 60 barg (871 psig), max. | 0.8 m³/h (3.5 gpm) |
| Speed range | 600 – 1200 rpm |
| HP max. outlet pressure | 83 barg (1200 psig) |
| HP min. inlet pressure | 20 barg (290 psig) |
| HP max. inlet pressure | 83 barg (1200 psig) |
| HP inlet min. pressure, intermittent | 3 barg (44 psig) |
| Max. differential pressure (HP in − HP out) | 5 bar (72.5 psi) |
| LP inlet max. pressure | 5 barg (72 psig) |
| LP inlet max. pressure, intermittent | 10 barg (145 psig) |
| LP outlet min. pressure | 1 barg (14.5 psig) |
| LP differential (in − out) at HP max. flow | 1.2 bar (17.5 psi) |
| Torque at max. differential pressure | 102 Nm (75 lbf-ft) |
| Max. starting torque (stick/slip) | 150 Nm (110 lbf-ft) |
| Operating Conditions | |
| Media temperature | 2 – 40°C (36 – 122°F) |
| Ambient temperature | 0 – 50°C (32 – 104°F) |
| Filtration requirement (nominal) | 5 micron melt-blown, 85% efficient |
| Salinity increase at membrane (40% recovery) | 2 – 3% |
| Sound pressure level LPA at 1 m | 84 dB(A) |
| Motor | |
| Motor size | 15 kW (20 HP) |
| Frame size | IEC 180 L |
| Poles | 6 |
| Nominal speed | 970 rpm |
| Speed range | 600 – 1200 rpm |
| Rated current | 30 A at 400 V |
| Rated motor torque at nominal speed | 146 Nm (107.7 lbf-ft) |
| Motor torque at min. speed | 129 Nm (95 lbf-ft) |
| Motor ambient temperature, max. | 40°C (104°F) |
| Motor insulation class | B |
| Motor degrees of protection | IP 55 |
| Weight & Footprint | |
| Weight (dry) | 305 kg (672 lb) |
| Footprint (horizontal) | 0.54 m² (5.81 ft²) |
| Identification | |
| Manufacturer | Danfoss High Pressure Pumps |
| Data sheet reference | Danfoss AI243586503158en-000404, §8.2 |
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:
Read the case study →
Read the case study →
Read the case study →
Read the case study →
Read the case study →
Read the case study →
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, both driven by the motor on a common shaft. 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 40 delivers up to 41 m³/h (180 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 40 for my plant?
What is the difference between 180F7004 and 180F7005?
What pre-filtration does it need?
Does it need a separate booster pump?
Does it need a VFD?
How is it shipped?
Specifications reproduced from Danfoss data sheet AI243586503158en-000404. 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.
