A default local coordinate system is applied to any membrane element that is not specifically included in the associated distribution. There are applications where a 75% rate of salt rejection is preferable to 95 to 99%, especially when it is achieved using only half of the energy. Unlike with RO membrane elements, the NF offerings of the major membrane manufacturers are quite different in performance from company to company.Spiral wound UF membrane elements are perfect for mimicking operating conditions that are representative of full size ultrafiltration membrane filtration systems. TORAY first began producing Reverse Osmosis and Nanofiltration spiral wound membrane elements in 1967, starting with cellulose acetate membrane elements. If not controlled, fouling and scaling will lead to higher operational costs that could result in higher energy demand, increased cleanings, and reduced lifetime of the membrane elements. Chemical attack and physical trauma to the membrane surface result in irreversible loss of performance; identifying the problem at an early stage can help save millions of dollars in membranes before excessive damage renders them useless. Although the outer dimensions are the same as those of existing Pentair X-Flow membrane elements with membrane areas of 55 m2 and 64 m2, the company has redesigned the internal workings and used modified materials to create extra membrane surface area. LONDON, United Kingdom – Global water treatment company Pentair announces the latest innovation within its X-Flow filtration solution portfolio, the Pentair X-Flow XF75 Membrane Element.The gases that arise at the electrodes are led off via a layer of porous material. The heart of the electrolyzer is the membrane, which is made from a polymer that is permeable to hydroxide ions but not to the hydrogen that arises. “We can test new materials on a small scale before quickly using them on a larger scale,” says Jan-Justus Schmidt. In this way, a private technical pastime could turn into a product that will take the world by storm. “For the formulation of the electrode pastes, we are benefiting greatly from the fact that the colleagues at Evonik know a lot about polymers and their properties,” says Barnett. This means that the team doesn’t have to start from scratch, but can instead use proven components to quickly develop and test new materials.Design modifications of the RFP element can reduce or virtually eliminate such feed velocity changes. A preferred embodiment of the invention utilizes a novel option inherently provided by the RFP to internally “stage” a single element. Accordingly, two, three or more membrane envelopes of different lengths can be wound about a single core tube yielding multiple stages as the feed volume decreases along its spiral path (see, e.g., Examples III and IV, infra).