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Hydranautics RO Membrane 4040


We offer the choice of two Hydranautics 4040 RO Membranes – ESPA4-4040 and ESPA1-4040. Both of these energy saving membranes fit standard 4” x 40” membrane housings and offer optimal performance at lower pressures without compromising the standard for high rejection. The ESPA4-4040 offers an average stabilised rejection rate of 99.2% and the ESPA1-4040 offers an average stabilised rejection rate of 99.3%. More detailed information including which membranes these are suggested alternatives to is below.

Why Choose Our Hydranautics RO Membranes 4040?

  • Suitable for all standard 4” x 40” membrane housings
  • High nominal rejection rates of up to 99.6%
  • Energy saving low pressure membranes
  • Genuine Hydranautics products

Need help with our Hydranautics RO Membranes 4040? Give us a call on 01622 933 853


Hydranautics ESPA (Energy Saving Polyamide) elements are specifically designed as a high flux/low pressure range of membranes. They deliver high rejection rates at lower operating pressures, saving on energy costs.

The ESPA4-4040 is a high rejection, extra low energy membrane that can run at operating pressures as low as 6.9 bar. It is a suitable alternative membrane to LG BW 4040 UES, Axeon HF4-4040 and Dow/Filmtec XLE-4040.

The ESPA1-4040 is a low energy, high production membrane that can run at operating pressures as low as 10 bar. It is a suitable alternative membrane to LG BW 440 ES, Axeon HF1-4040 and Dow/Filmtec LE-4040.

Key Product Information

  • High permeate flow rates of up to 9,800 Litres Per Day
  • Suitable alternatives to other 4040 RO membranes
  • Popular for commercial and industrial applications
  • High operating temperatures of up to 45⁰C
  • ESPA® (Energy Saving Polyamide)

Compatible Products

Need help with our Hydranautics RO Membranes 4040? Give us a call on 01622 933 853



ATD Diameter 100.3mm, Connection Diameter 19.1mm, Length 1016mm



Permeate Flow

ESPA4-4040: 9.46m³/day
ESPA1-4040: 9.8m³/day

Average Rejection Rate

ESPA4-4040: 99.2%
ESPA1-4040: 99.3%

Pressure Drop

10 PSI Per Element

Max Operating Temperature


Max Operating Pressure

600 PSI

Membrane Active Area


pH Range



Resources Available For This Product:

frank woolnough
frank woolnough
The first time using this site, and im more than pleasd with the service and delivery of the product. Will use again no problem.
Gary Kinsley
Gary Kinsley
Excellent service, fast delivery (although there was no urgency) and great after sales service from Becky who's very helpful and knowledgeable.
Eamonn Dorling
Eamonn Dorling
Prompt and well informed service
Marco Polo
Marco Polo
This company gives the best customer service I have EVER EXPERIENCED in the UK. If every company gave this much care and attention to their customers the UK would easily lead the world in business. Truly ⭐️⭐️⭐️⭐️⭐️ I cannot recommend enough Marco Crawford
Gary Barbour
Gary Barbour
The team were brilliant offering great advice, very knowledgeable on their products and I will definitely be using them again!
Alice Sefton
Alice Sefton
Really great service, I wasn't too sure what size of water filter to order so sent in a picture, the size was identified and the new filters were with me a day after purchase.
Jill and Garry Clark
Jill and Garry Clark
Excellent service.
Matthew Durdy
Matthew Durdy
Prompt service and follow up. Like it should be.
Resin cleaner turned up on time and worked as expected. Great service - Will use again

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