ESPA4 are the lowest feed pressure reverse osmosis membranes offering low energy consumption. ESPA4 membranes require ultra-low pressures without compromising high salt rejection and are commonly used in the second pass of a reverse osmosis system.
The ESPA4 reverse osmosis membranes are available in the LD variant. Low differential LD Technology® models are offered to minimize colloidal fouling when used with conventional pre-treatment equipment. These reverse osmosis membranes offer consistently low feed pressures and longer intervals between cleanings. ESPA4 reverse osmosis membranes are available in the MAX variant with 440 ft2 (40.9 m2) active membrane surface area. Increased membrane area reduces capital costs by requiring fewer pressure vessels and less floor space