Reverse Osmosis Systems
Reverse Osmosis (RO) was developed in the late 1950’s under U.S. Government funding, as a method of desalinating seawater. Reverse osmosis (RO) is a separation process that uses pressure to force a solvent (water) through a membrane, which retains the solute (contaminant) on one side and allows the pure solvent (water) to pass to the other side. More formally, it is the process of forcing a solvent from a region of high solute concentration through a membrane to a region of low solute concentrate by applying pressure in excess of osmotic pressure. This process is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied. The membrane here is semi-permeable, meaning it allows the passage of solvent (water) but not of solute (contaminant).
Under counter reverse osmosis systems filters in several phases. The first phase pre-filtration designed to protect the membrane by reducing fine suspended materials that can clog it and by removing the chlorine that damages thin film material membranes. The next is a semi permeable membrane to remove a wide variety of both aesthetic and health related contaminants. Next is a pressurized storage tank to hold the treated water and finally, carbon post filtration to remove any remaining aesthetic taste or odor. The typical under counter reverse osmosis system will operate under water pressure ranging from 40 and 100 psig. and generate 10 –75 gallons per day. The under counter reverse osmosis system is plumbed to the incoming cold water line, drain, and an independent faucet.
Counter top reverse osmosis systems provide an excellent alternative to under counter systems when a permanent installation is not desired or practical. Easy to install to virtually any standard faucet, the counter top unit has the same stages of filtration (pre-filtration, membrane and post filtration) and have similar daily capacities and operating parameters as the under counter systems. The primary difference is that the counter top system uses an atmospheric versus a pressurized storage tank.
The typical commercial reverse osmosis systems operate at water pressures between 100-225 psig. Their performance within that range depends upon the type of membrane(s) and the quality of the water being treated. Commercial systems are used in applications that demand large volumes of treated water (150-50,000 gallons) with high levels of purity. The filtration process used by commercial systems is the same as that used by typical residential reverse osmosis systems however, commercial systems become more complicated and expensive due the addition of such components as pumps, flow gauges, monitors, electrical supplies and more. Commercial systems can be installed in a wall, floor or frame mounted configuration.
Residential reverse osmosis membranes are produced in a spiral wound configuration and are generally of two different types: CTA (cellulose triacetate) which require a chlorinated water source and have a daily rated capacity of 10 -16 gallons per day; or TFC/TFM (thin film composite/thin film material) which require a non-chlorinated water source and have daily rated capacities ranging from 18-150 gallons per day. The standard spiral wound residential membrane is commonly referred to as a low-pressure membrane with an operating parameter of 40 -100 psi. The residential membrane can be produced in such a way it will fit any standard residential membrane housing or in such a way it fits only proprietary system design.
Commercial reverse osmosis membranes are offered in a spiral wound configuration. A commercial membrane requires an operating pressure between 100 – 225 psi, therefore, a pressure pump capable of delivering such pressure is needed. The membranes are designed to be used in a variety of applications such as tap, brackish and seawater treatment. "Nano" or water softening membranes are also available. The key elements when selecting a new or replacement commercial membrane are the size of the membrane, tape or fiberglass wrapped, type of application, capacity and operating pressure.
The most popular types of replacement filters are offered for both residential and commercial reverse osmosis systems. The range of filters includes those designed to mechanically remove sediment, particulates and even cysts; varieties of carbon filters to remove chlorine and organic contaminants; and special media filters targeted to remove specific contaminants. The leading U.S. manufacturers produce the filters. Standard and proprietary brands are available.
Although there are very few moving parts on a reverse osmosis system, there are parts that occasionally require replacement. We offer the most common replacement reverse osmosis parts and components to ensure you have any part you may need.
Replacement filters, membranes and parts can be located by selecting the brand of system you have. We list both standard and proprietary systems, offering easy access for your replacement needs.
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