Skip to Main Content
  • Instrumart
Instrumart logo
  • Products
  • Brands
  • Applications
  • Lab
  • Blog
  • Account
  • Email Us
  • 1-800-884-4967
  • What can we help you find?

    Can’t find what you’re looking for? Contact one of our engineers today. We’re open Mo-Th 8am to 5:30pm. Fr 8am to 5pm ET.
    • 1-800-884-4967
    • Email Us
    • Live Chat
  1. Process Controllers

Walchem W900 Series Flow Controller

Water treatment flow controller with eight relays & four input / output slots.

Walchem W900 Series Flow Controller
Walchem W900 Series Flow Controller
  • Walchem W900 Series Flow Controller
    Walchem W900 Series Flow Controller
  • Walchem W900 Series Flow Controller Side
    Walchem W900 Series Flow Controller Side
Walchem W900 Series Flow Controller
Walchem W900 Series Flow Controller
Walchem W900 Series Flow Controller
Walchem W900 Series Flow Controller Side
Retired products cannot be ordered
The Walchem Intuition-9 is the current replacement. Please contact an engineer for more information.

View Company Reviewsby Trustpilot
Manufactured
  • By Walchem
Includes
  • FREE Ground Shipping
  • FREE Lifetime Tech Support
Product Manual Product Specs
Questions?
Call 1-800-884-4967 or email sales@instrumart.com. Open Mo-Th 8am to 5:30pm. Fr 8am to 5pm ET.
Trustpilot

Overview

Features

  • Four I/O slots
  • Eight relay control outputs
  • Eight virtual inputs and outputs
  • On-screen and web page graphing
  • Ethernet for remote access
    • Internet, LAN or optional Modbus/TCP
  • UL, CSA, IEC & EN

Description

The Walchem W900 Series flow controller has a large display with icon based programming, making setup easy. With multiple language support, the Walchem W900 provides simple setup no matter where you business takes you. You can use the display for on-screen and web page graphing of sensor values and control output status or access that data remotely.

The Walchem W900 Series can also email alarm messages, datalogging reports, graphs, or system summary reports. Universal sensor input provides flexibility; the same controller can be used with almost any type of sensor needed. Four input / output slots allow complete flexibility in adding sensors, analog inputs, analog outputs and LPR corrosion sensors. Eight relay control outputs, eight virtual inputs and eight virtual outputs allow the controller to be used in a wide variety of applications.

Complete flexibility in the function of each relay

    • On/Off setpoint
    • Time proportional control
    • Pulse proportional control (only with 4-20mA or pulse solid state opto outputs)
    • Flow proportional control (only with 4-20mA or pulse solid state opto outputs)
    • PID control (when purchased with 4-20 mA or pulse solid state opto outputs)
    • In-range or out-of-range activation
    • Probe wash
    • Timer-based activation
    • Activation based upon the state of a contact closure
    • Timed activation triggered by water contactor or paddlewheel's accumulated total flow
    • Activate with another output
    • Activate as a percent of another output's on-time
    • Alarm
    • Spike set point
    • PPM volume
    • Target PPM
    • Flow meter ratio
    • Volumetric blending
    • Disturbance variable control

For Cooling Tower and Boiler applications:

  • Biocide timer
  • Boiler blowdown on conductivity using intermittent sampling

Documents

Spec Sheets

  • Walchem W900 Series Flow Controller Datasheet PDF (2.0 MB)

Manuals

  • Walchem W900 Series Flow Controller Manual PDF (15.8 MB)

Links

  • All possible part numbers

Accessories

Walchem WEL Series Electrodes
Walchem WEL Series Electrodes

Differential pH and ORP electrodes for industrial applications.

Starting at $173.00

Need Help? Call a Flow engineer at 1-800-884-4967

We're open Mo-Th 8am to 5:30pm. Fr 8am to 5pm ET

Mathias H. headshot Mathias H.
Senior Applications Engineer
15 years at Instrumart
Dan R. headshot Dan R.
Applications Engineer
3 years at Instrumart
Lou P. headshot Lou P.
Senior Applications Engineer
28 years at Instrumart
Martin K. headshot Martin K.
Applications Engineer
Patrick M. headshot Patrick M.
Applications Engineer
3 years at Instrumart
MaryKate R. headshot MaryKate R.
Applications Engineer
4 years at Instrumart
Jason D. headshot Jason D.
Senior Applications Engineer
22 years at Instrumart
Mathias H. headshot Mathias H.
Senior Applications Engineer
15 years at Instrumart
Dan R. headshot Dan R.
Applications Engineer
3 years at Instrumart
Lou P. headshot Lou P.
Senior Applications Engineer
28 years at Instrumart
Martin K. headshot Martin K.
Applications Engineer
Patrick M. headshot Patrick M.
Applications Engineer
3 years at Instrumart
MaryKate R. headshot MaryKate R.
Applications Engineer
4 years at Instrumart
Jason D. headshot Jason D.
Senior Applications Engineer
22 years at Instrumart
Mathias H. headshot Mathias H.
Senior Applications Engineer
15 years at Instrumart

Recently Viewed

Walchem W900 Series Flow Controller
Walchem W900 Series Flow Controller
United States Canada Mexico
Shop
Products
Brands
Applications
Support
Customer Service
Ask a Question
Live Chat
Track Order
Fraud Prevention
Financing
Our Company
Blog
About Us
Contact Us
Jobs
Travel Information
Our Team
Privacy Policy
Terms and Conditions of Sale
Accessibility Statement
Connect
1-800-884-4967
sales@instrumart.com
Instrumart
35 Green Mountain Dr
S Burlington, VT 05403 US
Mo-Th 8:00am to 5:30pm ET
Fr 8:00am to 5:00pm ET
Join Us on Facebook
Follow Us on X

Instrumart is a member of a family of industrial stores

Instrumart Compressor World Pump World BioPharm World Filtration World Motion World Qualitrol Engineered Solutions Wholesale Air Pipe
© Instrumart 2025

Family of Industrial Stores

Welcome to our family of stores, your go-to source for a wide selection of commercial and industrial products in the flow control and automation sectors. Each store features a curated range of specialized industrial solutions, with many items designed to complement each other, ensuring you can find everything you need for your specific application. Explore the stores below to discover our extensive product offerings for your business needs.

  • Instrumart

    Shop Industrial and Laboratory Instruments.

    Shop Now!
  • Compressor World

    Shop Compressed Air Equipment.

    Shop Now!
  • Pump World

    Shop Industrial, Water, and Waste Water Pumps.

    Shop Now!
  • BioPharm World

    Shop Sanitary Process Solutions and Products.

    Shop Now!
  • Filtration World

    Shop Industrial Filters.

    Shop Now!
  • Motion World

    Shop Motion Control and Process Automation Systems.

    Shop Now!
  • Qualitrol

    Shop Remanufactured or Repair Automation Products.

    Shop Now!
  • Engineered Solutions

    Shop Custom Engineered and Manufactured Systems.

    Shop Now!
  • Wholesale Air Pipe

    Shop Air Piping.

    Shop Now!