How A Permeate Pump Works With A Reverse Osmosis System – Useful Knowledge

Reverse osmosis is a water treatment process that pushes water under high pressure to remove contaminants through a semipermeable membrane. Still, let us tell you this: A reverse osmosis system will run more effectively with the aid of a permeate pump. Now, let’s learn how a permeate pump works with a reverse osmosis system.

A Full Reverse Osmosis System
A Full Reverse Osmosis System.

How A Permeate Pump Works With A Reverse Osmosis System: How Clear Are You About The Process?

When it comes to water treatment technology, osmosis is not a strange term at all. Yet, it’s normal if you find it unfamiliar because the term “osmosis” belongs to the science category. 

Therefore, before seeing how a permeate pump promotes its capabilities, we must first understand the reserve osmosis (RO) process.

In Reverse Osmosis System

We will divide the content into three sections to give you a thorough understanding of the reserve osmosis system and the roles of the permeate pump. Honestly, the contents are similar to a complex physical process, so we must learn about them step by step.


Osmosis is one of the most indispensable processes in nature. It happens when a weak saline solution naturally migrates to a stronger saline solution.

Let’s have a look at our illustrative image on how osmosis works as below!

Osmosis process

Imagine that you have a U-shaped tube separated into two parts by a  membrane. Now you fill water with a low salt concentration into one part of the tube and the other with a higher concentration. Wait a few minutes, then the water with the lower concentration starts to migrate towards the other. 

That sounds simple, but what is exactly that membrane?

A semipermeable membrane

A semipermeable membrane in osmosis lets only atoms or molecules pass through. It means others larger such as salts, organics, bacteria, or pyrogens, will get stuck and can not go over the membrane.

Big Components Cannot Pass through membrane
Big Components Cannot Pass.

Reverse Osmosis

Here we come to the last definition: reverse osmosis.

Naturally, osmosis doesn’t require energy. Suppose you start a reverse osmosis system, which is reverse with the normal process. In that case, you need to create pressure for the higher salt solution to desalinate (or called demineralize or deionize).

Reverse Osmosis System

Based on the principle of reverse osmosis above, people invented and developed a RO system as a means to filter water. 

An RO system could consist of 3, 4, or 5 stages of filtration and include a sediment filter, a carbon filter, and a membrane. 

You can classify the filters of pre-filters or post-filters based on the position of the water flow through the membrane. This sediment filter will limit some harmful particles, like dust or rust. Meanwhile, a carbon filter helps reduce some contaminants or chlorine, those that often make water taste bad and make it smell.

When we let the water come into the RO system, the available filters will filter some sediment and contaminants to avoid clogging the membrane. Then, water passes through the semipermeable membrane and deposits in a container. After that, the RO system continues to filter water. 

Here is the key: the power needed has to get over the natural pressure to push the water through the membrane. That’s why we need support from a permeate pump!

Permeate Pump of RO System
A Big RO System Should Have A Permeate Pump.

The Permeate Pump’s Operation

So how does a permeate pump work in a RO system?

Theoretically, a pump supplies enough power and creates pressure to push water flow faster during production. However, a permeate pump in the RO system doesn’t stop there.

How A Permeate Pump Works

In reverse osmosis, the permeate pump uses hydropower to run the process. Specifically, this pump creates the pressure from rejected water to get through the backpressure inside the tank, then produces the force to the storage tank. 

After creating enough power, the pump will deliver a powerful force to push the molecules over the membrane to collect clean water while decreasing the backpressure from the RO unit’s tank. Thanks to this special functionality, the resistance of backpressure is not a big problem anymore. As a result, reverse osmosis occurs more quickly than normal.

To be more specific, the pump performs its operation by some ports with every tube’s color below:

1. Brine In – Black Tube: Under pressure, water passes through the membrane housing’s port and flows into the pump.

2. Brine Out – Yellow Tube: When finished delivering power stored on the left side (of the pump), the brine is released and goes directly to the under sink drain pipe through a yellow tube.

3. Permeate In – White Tube: As the name suggests, the permeate from the RO unit’s membrane penetrates the right chamber. Of course, back pressure does not occur. The permeate accumulates in the pressure-free chamber of the pump until the brine side produces energies and powers them out of the chamber.

4. Permeate Out – Orange Tube: When powered by the energies, the permeate water accumulates inside the unit’s pressurized storage tank through an orange tube.

Advantages Of A Permeate Pump In An RO System

Let’s take a look at some advantages when we have the pump in the system.

During the RO process, the salt solution released from the tank is not waste liquid. In fact, the pump needs it to produce power and remove the impurities, producing a pure source of potable water. 

Unlike other pumps using electricity, a permeate pump operates by hydraulic energy. That’s why you can save energy in production and salvage the released water from the drain, supplying power to run the process. Hence, the expense is quite economical!

Generally, the RO process takes a lot of time to produce pure water since it creates resistance pressure naturally. The RO process will work more quickly and effectively with a permeate pump equipped to support the membrane.

Advantages Of A Permeate Pump
The Membrane Works Effectively.

Lastly, a permeate pump helps save the water that the process requires. A reverse osmosis process usually needs three gallons of water to create one gallon. However, a permeate pump will keep the same ratio of clean water to continue the process, which means you don’t need to supply the water source frequently. In consequence, you can decrease 85% of the water amount.

Should We Use An RO Booster Pump Instead?

The answer is no. We can use the booster pump in case the RO membrane cannot work effectively in high pressure, but it’s not good for the membrane. 

A permeate pump is more suitable if the main purpose is to support the RO system to separate harmful components to produce clean water. Although this pump does not specialize in boosting water pressure, it is designed to make the RO process more effective.

How To Set Up A Permeate Pump

Whether a permeate pump works efficiently mostly depends on the installation method. Let’s see how to install a permeate pump in the right way:

1. Focus on the labels with “brine in,” “brine out,” “permeate in,” and “permeate out.” They will be helpful in locating the tubing.

2. Screw the mounting clip to the manifold.

3. Add the pump into the clip with “brine out” and “permeate out”, then install the pump inside.

4. Turn around the RO system.

5. Take off the tubing from the permeate port of its membrane housing and remove the other tubing end from the ASO valve.

6. Add a new 22″ tube into the port of its membrane housing and put the tubing in the front of the system.

7. Put the tubing into the “permeate out” port, then add an elbow stem fitting into the “permeate out” point.

8. Add a 15″ section of the tubing into the fitting and connect the end-point to the ASO valve.

9. Find the flow restrictor, then give 22″ tubing into it.

10. Adjust the tubing toward the front of the system, then pass it through the holes in the mounting clip and put an elbow fitting at the end of the tubing.

11. Focus the “brine in” port and put the tubing into it. The final step to complete the installation is connecting the “brine out” port to the drain line.

Though doing it yourselves might be a good idea, it’s still technical and hard for any of us. In case you meet difficulties in setting up a pump, you should contact a service to ensure the right process and safety in operation.

A Short Summary

After reading our post, you now know how a permeate pump works with a reverse osmosis system and understand how essential it is in the process. Surely, you have had the reasons to equip one in reverse osmosis technology without worrying about its benefits. Let’s look for a professional supplier to help you select a suitable product with your system.

If you’re still wondering about related issues on this topic, read our many posts for detailed information!

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