Reverse Osmosis System Hookup

Recently, we have been getting a great deal of orders for reverse osmosis (RO) systems and components. Because we do not have an installation section dealing with ROs, it seems like this would be a good opportunity to make one

Finding A Location - Reverse osmosis systems in the 10 to 50 gallon-per-day range are intended to supply purified water for residential uses. They can be connected to a refridgerator's ice maker and water dispenser. They can also supply drinking water at the kitchen sink, and even at a wet bar or other location where purified water is desired.

The designers of these RO systems intend for them to be located under the kitchen sink in most applications. That seems to be the most popular spot judging by what most callers tell me. But if your home has a basement or crawl-space, the RO can go under the floor and supply lines can be run to both the drinking water dispensing location and your refridgerator's ice maker.

One thing to keep in mind when choosing a location for your RO is the fact that while they are low maintainence compared to faucet or pitcher filters, you will occasionally need to replace the sediment pre-filter and a relatively convenient location is more desireable.

Connections - Hooking all of those lines up is not a difficult task at all. The main thing to do is picture what connections you will need to make. The RO comes with a faucet. That will usually be at the kitchen sink or where ever water is most commonly dispensed. Another connection is to a supply line. The supply line can be the cold water (never introduce hot water into your RO unit) pipe running up to the kitchen sink's faucet. The ROs we sell all come with a self-tapping supply line fitting. You will also need a drain. Finally, a line from the output of the RO (membrane or carbon block filter) to a holding tank. As you can tell, it's a pretty simple operation. We'll deal with each of these four connections one at a time.

Supply Line - The supply line tap valve pictured here simply clamps on to your copper, brass or PVC water line and actually pierces the pipe when you tighten the valve down (clockwise). When you open the valve back up, water will flow through it into your RO system.

Here is a piercing RO supply valve. It clamps on to most sizes of cold water supply lines and pierces a hole in the pipe when you turn the valve stem clockwise. It is self-sealing and allows enough flow for a medium capacity RO system.	If you follow the red line from the RO, you can see where the piercing valve is connected to the cold water supply on this under-sink installation.

Drain Line - The drain line on any of the reverse osmosis systems that we sell connects to a saddle tee. It clamps on to most commonly sized drain pipes and the RO's drain line connects to it with a compression fitting. You will need to drill a small hole (1/8 to 1/4) in the drain pipe itself as this clamp is not self-tapping. I would strongly recommend clamping the saddle clamp onto the drain pipe before drilling the hole to insure proper positioning and alignment. Simply remove the compression fitting and drill into the pipe through the saddle tee's opening.

Once again in this photo, you can follow the black line to the kitchen sink's PVC drain. Clamp the saddle tee to the drain pipe above the drain's trap.

The Faucet - The output of the reverse osmosis system goes to the faucet included with your RO. This faucet generally is mounted to a corner of the kitchen sink by drilling a 9/16" hole and inserting the faucet while connecting the output line and a locking nut (to hold the faucet securely to the sink). The output line will attach with a compression fitting.

The reverse osmosis faucet comes with chrome and rubber washers to secure it to the mounting surface. The supply line connects to the bottom of the faucet with a compression fitting.

 

The Holding Tank Connection - All that is required here is to connect the line from the reverse osmosis unit labled "tank". The tank probably takes up the most space and its location should take in to account that it will possibly never need to be accessed. In other words, put it back and out of the way. The newer Microline RO systems we have come with a taller, more slender holding tank that makes less of a footprint than conventional models.

As you can see in this picture, the newer holding tanks, while taller are ideal for under-the-sink locations because they take up less floor space leaving plenty of room for the disposal.

Supplying A Second Output - An ice maker or refrigerator water dispenser can be easily connect to your reverse osmosis unit. Simply make a cut in the output line (before the faucet) and insert a tee. Run the second line to your ice maker and you're all set. All of our systems come with plenty of supply line but you may need extra if your second output appliance is far away. The plastic line used for RO systems is 1/4" OD (Outside Diameter) and is commonly available at any home improvement or hardware store.

This is an illustration showing the schematics of a typical reverse osmosis system. The tee in the output line is indicated as well as the functions of the different components that make up the system.

After connecting your RO, you will need to allow several hours for the membrane to process water and send it to the holding tank. The holding tank has a bladder and is pressurized just like a miniature version of a well tank. The flow rate at your RO faucet is going to be based on your holding tank's pressure, not your house pressure.

The instruction manual that comes with most of the reverse osmosis systems that we sell, will explain sterilization processes that need to be performed to insure that no bacteria can invade the system.

That's about all there is to it. The instructions that come with your particular RO will contain minor variations but the overall installation is really as simple as this article illustrates. A well planned installation should only take about an hour, or less time than it takes to run down to the local grocery store and buy bottled water.