TriSep Corporation, The Specialty Membrane Company | 1,125 followers on LinkedIn. TriSep Corporation is a specialty membrane manufacturer of spiral wound reverse osmosis, nanofiltration and ultrafiltration products. With a diverse product range and flexibility, we take pride in our ability to customize our product and service offering to address customers’ needs. In addition to offering industry-standard brackish water membrane elements, TriSep offers a wide range of specialty elements for process and sanitary applications, high temperature or high pressure operation and direct replacements for other membrane manufacturers – including many hard-to-find products that other companies have discontinued.