Watts R4X40 - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Installation Guidelines
Startup Procedure
Maintenance Features

This document is an installation and operation manual for a Watts Reverse Osmosis (RO) system, specifically the Model R4X40. The manual provides essential information for the proper setup, operation, and maintenance of the RO unit, which is designed to separate dissolved solids from water using semipermeable membranes.

Function Description:

The Watts R4X40 Reverse Osmosis system utilizes semipermeable membrane elements to purify water. Pressurized feed water is separated into two streams: purified (product) water and concentrate (reject) water. Impurities from the feed water are carried to the drain by the reject water. The system is designed to maintain adequate reject flow to prevent membrane scaling and/or fouling, which is crucial for its long-term performance. Proper pretreatment of the feed water is essential to prevent membrane damage and fouling. The system includes a pump to pressurize the feed water, prefilters to remove suspended solids, and RO membrane housings containing the membranes.

Important Technical Specifications:

The R4X40 series comes in three models: R4X40-1, R4X40-2, and R4X40-3, differing primarily in productivity and the number of membranes.

Maximum Productivity (gallons per day):
- R4X40-1: 2200
- R4X40-2: 4400
- R4X40-3: 6600
- Note: Maximum production is based on 77°F feed water, SDI < 1, 1000 ppm TDS, and pH 7. Individual membrane productivity may vary (± 15%).
Quality (average membrane rejection): 98%
Recovery (user adjustable):
- R4X40-1: 15-75%
- R4X40-2: 25-75%
- R4X40-3: 32-75%
- Note: Percent Rejection is based on membrane manufacturer specifications; overall system percent rejection may be less.
Membrane Size: 4" x 40"
Number Of Membranes:
- R4X40-1: 1
- R4X40-2: 2
- R4X40-3: 3
Prefilter: System ships with one 5 micron cartridge, 20" size.
Connections:
- Feed Water Connection: 3/4" NPTF
- Product Water Connection: 5/8" tubing OD
- Reject Water Connection: 5/8" tubing OD
Feed Water Requirements:
- Required (maximum):
  - R4X40-1: 10 gpm
  - R4X40-2: 12 gpm
  - R4X40-3: 14 gpm
- Pressure (minimum): 10 psi
Drain Required (maximum):
- R4X40-1: 10 gpm
- R4X40-2: 12 gpm
- R4X40-3: 14 gpm
Electrical Requirement (60 Hz):
- R4X40-1: 120 V - 15 amps
- R4X40-2: 120 V - 20 amps
- R4X40-3: 240 V - 12 amps
Motor Horse Power:
- R4X40-1: 3/4
- R4X40-2: 1
- R4X40-3: 1 1/2
Dimensions W x D x H (approximate inches):
- R4X40-1, R4X40-2: 20 x 20 x 50
- R4X40-3: 20 x 26 x 50
Shipping Weight (estimated pounds):
- R4X40-1: 120
- R4X40-2: 150
- R4X40-3: 180

Usage Features:

The system is equipped with several controls and indicators for ease of use:

On/Off Switch: For turning the unit on and off.
Indicators: Power, low-pressure, tank level, and pretreatment indicators provide system status.
Reject Control Valve (C): Adjusts the amount of reject flow.
Reject Recycle Control Valve (D): Controls the amount of recycle flow.
Pressure Gauges: Prefilter Outlet Pressure Gauge (E) and Pump Discharge Pressure Gauge (F) indicate pressures.
Flow Meters: Reject Flow Meter (G) and Product Flow Meter (H) display flow rates in gallons per hour (gph).
Water Quality Meter (L): Measures feed and product water Total Dissolved Solids (TDS) in parts per million (PPM). The meter is powered by two AAA batteries and automatically turns off after a few seconds.
Controller Connections: The controller supports connections for a tank level switch and pretreatment interlock switch, which can automatically shut off the system if conditions are not met. It also features a low-pressure reset time delay switch (5 or 30 minutes).

Installation Guidelines:

Proper pretreatment equipment must be determined and installed before the RO system.
The water supply and pretreatment equipment should provide a minimum of 10-psig at maximum feed flow.
An electrical receptacle with a ground fault interrupt (GFI) is highly recommended.
Installation must be indoors in an area protected from freezing, with adequate space for membrane removal.
Ensure a prefilter cartridge is installed in the housing.
Product water and reject water outlets should never be restricted. An air gap is required for the reject drain line.

Startup Procedure:

Verify pretreatment equipment is installed and working, and no free chlorine is present.
Ensure the on/off switch is off and a filter cartridge is installed.
Open the reject control valve completely (counterclockwise) and close the reject recycle control valve completely (clockwise).
Open the feed water shutoff valve.
Turn the controller on.
Flush the preservative from membranes for 15-30 minutes.
Adjust reject control valves to achieve desired flow rates, referencing the flow rate guidelines and temperature correction table in the appendix.
Allow product water to flow to drain for 30 minutes.
Turn off the system, connect the product line to the point of use, and restart the system.
Record initial operating data using the log sheet.

Maintenance Features:

Prefilter Replacement: Change the prefilter when the differential pressure across the housing increases by 5-10 psi over the clean cartridge pressure drop.
Membrane Cleaning: Clean the RO membrane(s) when the product flow drops by 15% or more.
Membrane Replacement:
1. Turn off the system, close the feed water shutoff valve, and unplug the unit.
2. Disconnect tubing from the top of membrane housing(s).
3. Loosen clamps and remove top end cap(s).
4. Remove old membrane(s) by pulling them up (pliers may be needed).
5. Install new membrane(s) in the same orientation as the old ones, ensuring the brine seal does not flip up or roll. Use glycerin lubricant and a gentle twisting/rocking motion. If unable to install brine seal first, lay the unit over, remove the bottom end cap, and install the brine seal last.
6. Reconnect tubing and follow the startup procedure.
Troubleshooting Guide: The manual includes a comprehensive troubleshooting guide for common issues such as high product water TDS, no product water, decreased permeate flow, increased salt passage, and various types of fouling (metal oxide, colloidal, scaling, biological, organic, chlorine oxidant attack, abrasion). It provides symptoms, possible causes, verification methods, and corrective actions.
Operation and Maintenance Log: A log sheet is provided to record operational data such as product GPM, reject GPM, pump discharge pressure, feed TDS, product TDS, feed water temperature, feed water hardness, feed water chlorine level, prefilter inlet pressure, and prefilter outlet pressure. This log is crucial for diagnosing and preventing system problems and for warranty claims.