Danfoss RO Pumps — Authorized Distributor of the Full Danfoss APP Series for Reverse Osmosis
The Danfoss APP series is the industry-standard high-pressure pump for reverse osmosis (RO) — used in seawater desalination, brackish water RO, and industrial high-pressure water applications from 200 GPD watermakers to 1,000,000+ GPD plants. ForeverPure has been an authorized Danfoss distributor since 2003 and stocks every APP model from APP 0.6 through APP 86. Same-week dispatch from Denmark and California warehouses.
Request a Danfoss RO Pump Quote → · +1-408-969-2688
What Is a Danfoss RO Pump?
A Danfoss RO pump is a positive-displacement axial-piston high-pressure pump from Danfoss's APP (Axial Piston Pump) series, engineered specifically for reverse osmosis duty. Unlike conventional triplex plunger pumps, the Danfoss APP is lubricated by the water it pumps — no oil, no crankcase, no contamination risk. Wetted parts are super-duplex 2507 stainless steel for full chloride immunity in seawater service.
Output pressure: 55–80 bar (800–1,160 psi) — exactly the operating range for SWRO and high-recovery BWRO. Service life: 50,000–80,000 operating hours between overhauls (8–15 years of continuous SWRO duty). Efficiency: 90–92% — significantly above the 70-78% of multistage centrifugal alternatives.
Full Danfoss RO Pump Lineup In Stock
ForeverPure stocks the complete Danfoss APP RO pump series. Order any model for same-week dispatch:
| Model | Part Number | Flow @ 800 psi | Typical SWRO Output | Stock |
|---|
| APP 5.1 | 180B3005 | 5.1 m³/h (22 GPM) | ~2,000 GPD | ✅ In stock |
| APP 6.5 | 180B3006 | 6.5 m³/h (29 GPM) | ~2,600 GPD | ✅ In stock |
| APP 8.2 | 180B3008 | 8.2 m³/h (36 GPM) | ~3,300 GPD | ✅ In stock |
| APP 10.2 | 180B3010 | 10.2 m³/h (45 GPM) | ~4,100 GPD | ✅ In stock |
| APP 11 | 180B3011 | 11.0 m³/h (48 GPM) | ~4,400 GPD | ✅ In stock |
| APP 16 | 180B3254 | 16.0 m³/h (70 GPM) | ~6,400 GPD | ✅ In stock |
| APP 17 | 180B3255 | 17.0 m³/h (75 GPM) | ~6,800 GPD | ✅ In stock |
| APP 19 | 180B3256 | 19.0 m³/h (84 GPM) | ~7,600 GPD | ✅ In stock |
| APP 22 | 180B3257 | 22.0 m³/h (97 GPM) | ~8,800 GPD | ✅ In stock |
| APP 24 – 86 | 180B30XX | 24–86 m³/h | 9,600–34,400 GPD | 2-4 weeks factory |
Smaller models APP 0.6 through APP 3.5 are also available — used in portable watermakers and pilot systems. Browse the complete Danfoss APP catalog →
Why the Danfoss APP Dominates RO Pump Service
- Seawater-lubricated. No oil. No crankcase seals to fail. No contamination of product water if a seal weeps. Critical for marine, beverage, and pharmaceutical applications.
- Super-duplex 2507 wetted parts. PREN >40 — immune to chloride corrosion at full seawater concentration (40,000 ppm TDS). Standard 316L SS fails in chloride service within 2-5 years; Danfoss APP runs 15-25 years.
- 90-92% efficiency. The single largest energy consumer in any RO plant. A 2% efficiency advantage over centrifugal alternatives translates to thousands of dollars per year on a 50,000 GPD system.
- VFD-compatible from 30-100% capacity. Reliable operation at low flow without cavitation — essential for solar-powered or variable-demand installations.
- 50,000-80,000 hour service life. 8-15 years of continuous SWRO duty between overhauls. Spare parts available worldwide; we stock O-ring kits, seal kits, valve kits, and cylinder barrels in California.
- Quiet — 65-75 dB(A). Acceptable for shipboard and residential-adjacent installations where centrifugal alternatives would be too loud.
Sizing a Danfoss RO Pump for Your System
Three inputs determine the right APP model:
- Required permeate output (gallons per day or m³/hour at your operating recovery)
- System recovery rate (35-45% for SWRO, 65-85% for BWRO)
- Energy recovery configuration — with an ERI PX or FEDCO HPB, the HP pump only supplies the permeate flow (not full feed flow), letting you use a much smaller APP model
Worked example: Coastal hotel needs 30,000 GPD SWRO with ERI PX-Q300 energy recovery. Permeate flow = 30,000 GPD ÷ 24h = 20.8 GPM = 4.73 m³/h. With 10% design margin: 5.2 m³/h. Select Danfoss APP 5.1 (180B3005).
Send us your feed-water analysis and target permeate output — our engineers confirm pump selection and quote within 24 hours. Request engineering support → or read the complete Danfoss Pumps Buyer's Guide for full sizing methodology.
Danfoss RO Pump Pricing
Indicative pricing (USD, before freight and spares):
| Series | Indicative Price | Typical Use |
|---|
| APP 0.6 – APP 3.5 | $2,500 – $5,500 | Portable watermakers, pilot systems |
| APP 5.1 – APP 10.2 | $6,500 – $12,000 | Commercial SWRO 2,000-4,000 GPD |
| APP 11 – APP 22 | $13,000 – $22,000 | Mid-scale SWRO 4,400-8,800 GPD |
| APP 24 – APP 38 | $24,000 – $38,000 | Large commercial 10,000-15,000 GPD |
| APP 43 – APP 86 | $42,000 – $85,000 | Industrial 17,000-34,000 GPD |
Final pricing depends on configuration (standard APP vs S/T/W variant), motor selection, baseplate, and quantity. Request a formal quote →
Danfoss RO Pump vs Triplex Plunger vs Centrifugal
| Criterion | Danfoss APP | Cat Pumps Triplex | Grundfos BME |
|---|
| Mechanism | Axial piston | Triplex plunger | Multi-stage centrifugal |
| Lubrication | Seawater | Oil | Compatible water |
| Materials | Super-duplex 2507 | 316 SS or Duplex | 316 SS or Titanium |
| Efficiency | 90-92% | 85-90% | 70-78% |
| Best for | 2,000-35,000 GPD SWRO | Portable <2,000 GPD | 250,000+ GPD municipal |
| Service life | 50,000+ hr | 15,000-30,000 hr | 60,000+ hr (no shock) |
| 5 m³/h class price | ~$8,500 | ~$6,000 | ~$25,000 (larger class) |
Bottom line: For commercial RO from 2,000 to 35,000 GPD, Danfoss APP wins decisively on efficiency, materials, and total cost of ownership.
Danfoss RO Pump Spare Parts & Service
ForeverPure stocks every standard Danfoss APP service kit:
- O-ring kits (annual service)
- Seal kits with wear rings (every 8,000-12,000 hours)
- Valve kits (every 20,000-40,000 hours)
- Cylinder barrel sets — e.g., Danfoss 180B4140
- Piston/shoe assemblies
- Swash plate assemblies
Overnight shipping available for production-stopping failures. Email sales@ForeverPurePlace.com with your model number and part need.
Danfoss RO Pump — Frequently Asked Questions
What's the difference between a Danfoss RO pump and a regular high-pressure pump?
A Danfoss RO pump (the APP series) is engineered specifically for reverse osmosis duty. It uses the pumped water (seawater or brackish) to lubricate internal bearings, eliminating the need for oil. The wetted parts are super-duplex stainless steel for chloride resistance. Conventional high-pressure pumps require external oil lubrication and use lower-grade stainless that fails in saltwater service.
Which Danfoss APP model is right for my RO system?
It depends on permeate output and whether you have energy recovery (ERD). With an ERI PX or FEDCO HPB ERD, sizing is based on permeate flow only. Without ERD, you need to size for full feed flow. Quick guide: 200-2,000 GPD permeate → APP 0.6-1.5; 2,000-5,000 GPD → APP 5.1-6.5; 5,000-10,000 GPD → APP 8.2-11; 10,000-25,000 GPD → APP 13-22; 25,000-50,000 GPD → APP 24-43.
How much does a Danfoss RO pump cost?
Danfoss APP RO pumps range from approximately $2,500 (APP 0.6) to $85,000+ (APP 86). Commercial sizes APP 5.1 through APP 22 are typically $6,500-$22,000. Final price depends on variant (standard, S/T/W), motor selection, and quantity. Request a formal quote with your system specifications.
How long does a Danfoss RO pump last?
A properly sized and maintained Danfoss APP RO pump runs 50,000-80,000 operating hours between major overhauls — typically 8-15 years of continuous SWRO duty. Total pump service life including overhauls often exceeds 25 years. The #1 failure cause is poor pretreatment letting abrasive particles reach the piston/shoe interface, so good cartridge filtration (5 µm minimum) is essential.
Can a Danfoss RO pump run dry?
No — Danfoss APP pumps are seawater-lubricated. Running dry even briefly will cause severe damage to the piston/shoe interface within seconds. Always verify the booster pump has prime and positive inlet pressure before starting the APP. Install low-pressure interlocks that automatically shut down the system if suction pressure drops below NPSH.
Where do you ship Danfoss RO pumps from?
ForeverPure ships from two warehouses: Denmark (factory-direct stock) and California (USA stocking warehouse). Commercial sizes APP 5.1 through APP 22 ship within 3-7 business days. Larger industrial models APP 24-86 may have 2-4 week factory lead times. Overnight emergency shipping is available for production-stopping failures.
Is ForeverPure an authorized Danfoss distributor?
Yes. ForeverPure Corporation has been an authorized Danfoss High Pressure Pumps distributor since 2003. We supply commercial and industrial customers worldwide with new pumps, replacement parts, and engineering support. All pumps ship with full Danfoss factory warranty.
