Hydranautics ESPA4-LD-4040 Membrane

Product Description

ESPA4 membranes require ultra-low pressures without compromising standards for high flux and high salt rejection. ESPA4 membrane has been commonly used in drinking water production from well and surface waters in the water treatment industry. It is widely accepted due to significant operational cost savings associated with their use.

Due to their ultra-low feed pressure requirement, ESPA4 membranes have been accepted as a standard in the second pass of a two pass reverse osmosis systems.

ESPA4-LD are ultra-low pressure brackish water membranes that use patented Low Differential LDTM technology designed to minimize colloidal fouling.


ESPA4-LD-4040 Specifications:
  • Permeate Flow: 2,350 gpd (8.90 m3/d)
  • Salt Rejection: 99.2% (99.0% minimum)
  • Type Configuration: Spiral Wound
  • Membrane Polymer: Composite Polyamide
  • Membrane Active Area: 80 ft2 (7.4 m2)
  • Feed Spacer: 34 mil (0.864 mm)

The stated performance is initial (data taken after 30 minutes of operation), based on the following conditions:

  • 500 ppm NaCl solution
  • 100 psi (0.7 MPa) Applied Pressure
  • 77 °F (25 °C) Operating Temperature
  • 15% Permeate Recovery
  • 6.5 - 7.0 pH Range



Standard Operating Limits:
  • Maximum Applied Pressure: 600 psig (4.14 MPa)
  • Maximum Chlorine Concentration: < 0.1 PPM
  • Maximum Operating Temperature: 113 °F (45 °C)
  • pH Range, Continuous (Cleaning): 2-10 (1-12)
  • Maximum Feedwater Turbidity: 1.0 NTU
  • Maximum Feedwater SDI (15 mins): 5.0
  • Maximum Feed Flow: 16 GPM (3.6 m3/h)
  • Minimum Ratio of Concentrate to Permeate Flow for any Element: 5:1
  • Maximum Pressure Drop for Each Element: 15 psi



  • Municipal Potable and Wastewater Plants
  • Bottling Operations
  • Light Industrial


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(1 review) Write a Review
  • 5
    They know their products

    Posted by Majid G. on Mar 8th 2018

    These guys are awesome...they helped us to get a replacement for a discontinued products.

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