How Do Reverse Osmosis Filter Systems Work & What Do They Do?
If you’re looking for a water filter that will provide outstanding drinking water for your home or business, Reverse Osmosis (RO) filtration is one of the most popular and best water filtration methods available. In simple terms, reverse osmosis works as water is forced across a semi-permeable membrane, leaving contaminants behind that are flushed down the drain. The clean drinking water collects in a holding tank.
Millions of American households and businesses love Reverse Osmosis (RO) because:
· RO produces great-tasting water
· RO is effective and safe
· RO filtration is fully automated
· RO systems are reasonably priced
Below you will find diagrams, charts and explanations to answers your questions about RO systems. If you have other questions which are not answered here, please visit our our main water education page or Contact Us.
Why is Reverse Osmosis a Good Water Filtration Option?
We’ve been in the water filtration business since 1991 and have found Reverse Osmosis filtration to consistently be one of the best ways to achieve superior water for the home and business.
Reverse Osmosis
If you're searching for a water
filtration system that will give you outstanding water...
Here are a few reasons to consider RO:
1.Improves Taste
RO filtration improves taste, odor and appearance of water by removing contaminants that cause taste and odor problems.
2.Saves Money
With an RO system, you can cancel your water delivery service and stop purchasing cases of bottled water. Reverse Osmosis filtration provides “better-than-bottled water” quality water for just pennies per gallon.
3.Simple Maintenance
RO systems have very few moving or replaceable parts make RO systems easy to clean and service.
4.Removes Impurities
RO systems remove pollutants from water including nitrates, pesticides, sulfates, fluoride, bacteria, pharmaceuticals, arsenic and much more. An RO systems’ carbon filter will also remove chlorine and chloramines.
Reverse Osmosis filtration is the perfect solution if you’re looking to improve the taste, odor and appearance of your water. Here are some of the most common applications for RO technology:
Top Residential RO Sellers:
Installed at the kitchen sink: A small RO filtration system can be installed at the kitchen tap to provide top-quality drinking water. This is called a “point of use” (POU) water filtration system and can also connect to your fridge and ice machine. Water pressure is a consideration with some refrigerators, so be sure to refer to your RO system’s owner’s manual as the pressure from the Reverse Osmosis unit is about two-thirds of the incoming line pressure. Related content: Can I Install a Reverse Osmosis System Myself?
Top Whole-House RO Sellers:
Whole-house RO system: A whole-house Reverse Osmosis system (also called a POE “point of entry” system) allows you to have filtered water at all sinks, showers and appliances throughout the house. A POE system ties into the main water line coming into your home and is generally installed in the garage. This type may not always be an available option due to the upfront cost of such a large filtration system, as well as requiring more long-term maintenance and service.
Top Commercial RO Sellers
Reverse Osmosis is a perfect fit for many businesses. At ESPWaterProducts.com, we carry a wide variety of large RO systems designed for many different commercial applications.
Common Commercial Reverse Osmosis (RO) System Applications:
How Does Reverse Osmosis Work?
Reverse Osmosis water purification process is a simple and straightforward water filtration process. It is accomplished by water pressure pushing tap water through a semipermeable membrane to remove impurities from water. This is a process in which dissolved inorganic solids (such as salts) are removed from a solution (such as water).
A few impurities found in tap water that can be removed with Reverse Osmosis filtration technology:
· Fluoride
· Lead
· Chlorine & Chlormamine
· Pesticides
· Detergents & more
· Nitrates & Sulfates
What Happens To The Contaminants That Don’t Pass Through The Membrane?
When household water pressure pushes water through the RO membrane and additional filters, such as sediment or carbon filters, the impurities are filtered out and subsequently flushed down the drain. What is left, is delicious, clean-tasting drinking water. Note that many RO units incorporate a 4 or stage process for optimal water quality.
You may be interested to know that Reverse Osmosis technology is not new. In fact, RO processes began being utilized by municipalities back in 1977. Since then, Reverse Osmosis has become increasingly popular because it is safe, cost-effective, and easy to maintain.
RO Filter Systems: What Are The Basic Components Of An RO System?
Generally, residential "Point Of Use" POU RO systems are installed and stored under the kitchen sink. Regarding the common components of a four to five-stage RO system, note that:
· Most RO systems look similar and have the same basic components.
· Although most RO systems look and work basically the same way --they differ in the QUALITY of their components.
Basic Components Of A Reverse Osmosis System:
1. Cold Water Line Valve: Valve that fits onto the cold water supply line. The valve has a tube that attaches to the inlet side of the RO pre filter. This is the water source for the RO system.
2. Pre-Filter(s): Water from the cold water supply line enters the Reverse Osmosis Pre Filter first. There may be more than one pre-filter used in a Reverse Osmosis system, the most common being sediment and carbon filters. These pre-filters are used to PROTECT the RO membranes by removing sand silt, dirt, and other sediment that could clog the system. Additionally, carbon filters may be used to remove chlorine, which can damage the RO membranes.
3. Reverse Osmosis Membrane: The Reverse Osmosis Membrane is the heart of the system. The semipermeable RO membrane is designed to remove a wide variety of both aesthetic and health-related contaminants. After passing through the membrane, the water goes into a pressurized storage tank where treated water is stored.
4. Post filter(s): After the water leaves the RO storage tank, but before going to the RO faucet, the treated water goes through a final “post filter”. The post filter is usually a carbon filter. Any remaining tastes or odors are removed from the product water by post filtration “polishing” filter.
5. Automatic Shut Off Valve (SOV): To conserve water, the RO system has an automatic shut off valve. When the storage tank is full, the automatic shut off valve closes to stop any more water from entering the membrane and blocks flow to the drain. Once water is drawn from the RO faucet, the pressure in the tank drops; the shut off valve then opens to send the drinking water through the membrane while the contaminated wastewater is diverted down the drain.
6. Check Valve: A check valve is located in the outlet end of the RO membrane housing. The check valve prevents the backward flow of treated water from the RO storage tank. A backward flow could rupture the RO membrane.
7. Flow Restrictor: Water flowing through the RO membrane is regulated by a flow restrictor. There are many different styles of flow controls, but their common purpose is to maintain the flow rate required to obtain the highest quality drinking water (based on the gallon capacity of the membrane). The flow restrictor also helps maintain pressure on the inlet side of the membrane. Without the additional pressure from the flow control, very little drinking water would be produced because all the incoming water would take the path of least resistance and simply flow down the drain line. The flow control is most often located in the RO drain line tubing.
8. Storage Tank: The standard RO storage tank holds from 2 - 4 gallons of water. A bladder inside the tank keeps water pressurized in the tank when it is full. The typical under counter Reverse Osmosis tank is 12 inches in diameter and 15 inches tall.
9. Faucet: The RO unit uses its own faucet, which is usually installed on the kitchen sink. Some areas have plumbing regulations requiring an air gap faucet, but non-air gap models are more common
10. Drain line: This line runs from the outlet end of the Reverse Osmosis membrane housing to the drain. The drain line is used to dispose of the wastewater containing the impurities and contaminants that have been filtered out by the reverse osmosis membrane.
Diagram of a Reverse Osmosis System with Basic Components:
At ESP Water Products, we’ve been selling water filtration equipment for 25+ years. This longevity in the industry has made us very selective in what we sell and endorse. We carry only RO systems that have won our confidence--those that are manufactured with the highest-quality components, offer outstanding warranties, and have the highest ratings for customer satisfaction.
What does a Reverse Osmosis system do?
Public water suppliers work hard to provide clean water for their customers. The problem is that there are many contaminants, especially those that cause taste and odor issues, which are simply not EPA regulated. These contaminants can easily penetrate aquifers, streams and rivers, bringing impurities straight to your water lines.
Produce Outstanding Drinking Water With Reverse Osmosis
That’s where Reverse Osmosis comes in. With a Reverse Osmosis filtration system, you can filter out impurities and produce outstanding drinking water for your home or business.
Want To Know More About What A Reverse Osmosis System Can Remove?
How does a Reverse Osmosis Membrane work?
Reverse Osmosis (RO) is a water treatment process that removes contaminants from water by using pressure to force water molecules through a semipermeable membrane. During this process, the contaminants are filtered out and flushed away, leaving clean, delicious drinking water. Reverse osmosis is capable of removing up to 99 percent of 65 different contaminants (see partial list below), including lead, fluoride, chlorine, dissolved salts, and more.
There Are Generally Four Stages In The Reverse Osmosis Process:
SEDIMENT FILTER:
This pre-filter stage is designed to strain out sediment, silt, and dirt and is especially important as the sediment filter protects dirt from getting to the delicate RO membranes that can be damaged by sediment.
CARBON FILTER:
The carbon filter is designed to remove chlorine and other contaminants that affect the performance and life of the RO membrane as well as improve the taste and odor of your water.
REVERSE OSMOSIS MEMBRANE:
The semipermeable RO membrane in your RO system is designed to allow water through, but filter out almost all additional contaminants.
POLISHING FILTER:
In a four-stage RO System, a final post filter (carbon filter) will “polish” off the water to remove any remaining taste and odor in the water. This final filter ensures you’ll have outstanding drinking water.
Some factors that may affect the performance of a Reverse Osmosis System:
· Incoming water pressure (most on municipal city tap water have 40-85 psi, but if water pressure is too low, RO system will not operate properly)
· Water Temperature (i.e. cold water takes longer to filter to filter)
· Type and number of total dissolved solids (TDS) in the tap water
· The quality of the filters and membranes used in the RO System (see operating specifications for your system)
Reverse Osmosis Membrane Operating Conditions And Performance Data
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Are all Reverse Osmosis drinking water systems and filters the same?
There are many different Reverse Osmosis (RO) water filtration systems on the market. While one RO System may look like the next in terms of design and components, there can be substantial differences between systems.
Reverse Osmosis (RO) Systems Differ in Three Basic Ways:
· Number of stages or filters
· Quality of their components
· Amount of water that can be filtered or produced each day (this amount is in “gpd” or gallons per day)
Quality Components Are The Key To An Optimal Functioning RO System.
In our 25+ years in the industry, we’ve found that the quality of components is truly the key differentiation between systems. This is because RO units manufactured using excellent craftsmanship, as well as superior parts and components are what ultimately produce the best intended results--top-quality water for the home and business.
As you compare RO systems to find the product that is right for you, be sure to ask yourself these 5 questions:
1. Does this system have good reviews?
2. Does it use quality parts from trusted manufacturers, and are the materials FDA or NSF (National Sanitation Foundation) approved?
3. Is the technology up-to-date?
4. Some systems have higher contaminant rejection abilities. How does this one compare to others like it?
5. Read up on the company. Is it reputable?
How much service and maintenance does an RO system require?
Reverse Osmosis Drinking Water Systems Are Easy To Maintain And Upkeep Costs Are Minimal.
1. Replacement filters: RO membranes and filters will need to be replaced every 6 months to 2 years depending on the type of filter, your water quality and your water usage volume.
Generally, filters should be changed following this schedule:
· Pre-filters (sediment/carbon filters): Every 6-12 months
· RO Membrane: Every 2-3 years
· Post filter (carbon filter): Every 12 months
· Not sure how often your parts need replacement? Replacement recommendations are listed under each product’s “SPECS”
This guideline is very general. Specific information about how often your membrane or filter should be replaced can be found in the products’ “Specs” or your product owner’s manual. If you’ve purchased a system or filter from us in the past, we will send reminder emails when it comes time to change your filter.
2. Electricity Charges: All of our residential Reverse Osmosis systems require no electricity, running only on water pressure. Some of our larger commercial systems do have to use electric pumps, but even then the power requirements are minimal.
3. Annual Maintenance: We recommend that you have your RO system sanitized and filters changed once each year. This can be done by the homeowner or by a local water treatment professional. A water professional can provide needed maintenance service or consult your RO system’s owner’s manual. We also carry kits and the filters to perform the annual sanitation and filter change if you’re a do-it-yourself type.
How Long Will An RO System Last?
If you properly care for your Reverse Osmosis system (annual cleanings plus change out filters/membranes on time), your system should have a very long lifespan; we’ve seen properly-maintained systems last 10-15 years!
We highly recommend that you purchase replacement filters from us, as we only carry top-quality filters that are designed for optimal performance and reliability.