ERI PX-300 Pressure Exchanger: Specifications, Price, and Application Guide

The ERI PX-300 is a 300 GPM (68 m³/h) isobaric pressure exchanger, the workhorse energy recovery device for commercial seawater reverse osmosis (SWRO) systems in the 20,000–50,000 GPD range. At 97%+ pressure transfer efficiency, the PX-300 reduces SWRO energy consumption by 55-60% compared to systems without energy recovery — typical payback is 12-18 months.

PX-300 Quick Specifications

How the PX-300 Works in an SWRO System

In a typical PX-300 installation:

1. The high-pressure pump (e.g., Danfoss APP 10.2) pressurizes only the permeate fraction (~40% of total feed) to ~800 psi
2. This pressurized feed mixes with PX-300 output (the other 60% of feed, also pressurized to ~800 psi by the brine recovery)
3. Combined feed enters the membrane vessels
4. High-pressure brine reject (60% of feed at ~795 psi) returns to the PX-300 low-pressure side
5. The PX-300's ceramic rotor transfers brine pressure to incoming low-pressure feed water
6. Depressurized brine exits to discharge; newly pressurized feed enters the recirculation loop

Net energy savings: approximately 60% versus a comparable system with no energy recovery.

PX-300 vs PX-Q300 — Which Should You Choose?

The PX-300 and PX-Q300 have identical flow ratings but differ in:

• Noise: PX-300 ~78 dB(A), PX-Q300 ~71 dB(A) — 7 dB quieter
• Efficiency: PX-300 ~97%, PX-Q300 ~98%
• Price: PX-Q300 costs ~10% more
• Best for: PX-300 for industrial/remote installations; PX-Q300 for hotels, hospitals, residential-adjacent

Installation Requirements

• Clean feed water (5 μm pre-filtration mandatory; 1 μm strongly recommended)
• Stable feed pressure 30-50 psi from booster pump
• Brine return line piped directly back to PX low-pressure inlet
• Mounting on isolated baseplate to minimize structural noise transmission
• Ambient temperature -10°C to +50°C (-15°F to 120°F)

Maintenance

Annual: Visual inspection of inlet/outlet ports for scale buildup. 5-year: Rotor inspection (typically no replacement needed even after 10+ years of continuous service). Lifetime expectancy of the PX-300 housing exceeds 25 years.

Get a PX-300 Quote

Send us your SWRO system specs (target permeate flow, feed water TDS, operating hours) and we'll confirm PX-300 fit and provide a formal quote within one business day.

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