APEC Online Technical Guide 2

Make Sure the RO membrane is inserted correctly

Two Common Mistakes:

1) Forget to put the Membrane into its housing.

2) Insert Membrane into housing in the "wrong" direction.

When you install the RO system, if you forget to put the membrane into its housing, or put it in the "wrong" (reversed) directon --> your water will not be filtered, and the RO will vibrate or make humming noise when you dispense water.

How to check your RO membrane: Open up the membrane housing cap (remove Red tubing from cap) and look inside the housing. If you see a Black seal, then it's inserted correctly. See diagrams below.

This is what the membrane looks like:

Figure A: Correct way to insert Membrane




Figure B: System Connection Diagram

Please refer to the diagram below to make sure that you have proper water line connections.

There are 4 connections:

Point A to X: Connect RO to COLD water supply - Red tubing.
Point B to Y: Connect product water from 5th-stage filter to tank - Yellow* tubing.
Point C to Z: Connect product water from 5th-stage output to dispensing faucet - Clear tubing.
Drain line to W: Connect waste water from 4th-stage membrane to drain outlet - Black tubing.

* Note: The Yellow tubing is a 2-way line. Product water enters and leaves the tank via this same line.


Figure C: System Troubleshooting Points Diagram

The diagram below identifies testing points for troubleshooting procedures.

Troubleshoot Points Identification:

Point A: Feed water inlet into Stage-1 filter

Point B: Stage-3 filter's outlet port

Point C: Automatic-Shut-Off (ASO) valve. For Permeate Pumped systems, the permeate pump replaces the ASO valve, it serves both as a pump and an auto-shut-off valve.

Point D: Stage-4 Membrane housing inlet port. Feed water after passing the 3 prefilters enters the Membrane at this port.

Point E: Check Valve. The filtered water from the Membrane passes through this Check Valve before it enters the storage tank. The Check Valve serves to block the water from back-flowing from the tank back into the membrane.

Point F: T-fitting on the Stage-5 filter. This end of the T-fitting connects to the CLEAR pure water line.

Point G: T-fitting on the Stage-5 filter. This other end of the T-fitting connects to the YELLOW pure water line which goes to the tank's valve.

Point H: The output end of Stage-5 filter. Pure water leaves Stage-5 filter via this port, and flows onto the dispensing faucet.


How To Use Quick-Connect Fittings

Below are samples of Quick-Connect type fittings on your RO systems. When connect tubing to these fittings, simply insert tubing into the fitting's ports. Please Do Not add "tube inserts" to these connections!

Quick-Connect Fittings:

How To Connect & Remove Tubing:

To Connect: Simply insert tubing into the fitting port tightly.

To Disconnect: Push-in and hold down on the collet ring at the base of fitting port, then pull out tubing.


System Flow Diagram