Water Purification

Water Purification

Reverse Osmosis

A Reverse Osmosis System is a Cross Flow Water Purification Process.

Raw Water is forced into the membrane housing under pressure – as high as 800 PSI. The water is forced through the membrane and enters the center tube without most of it’s contaminants which are discharged to drain.

We offer Packaged Reverse Osmosis Systems :

  • Small Scale
  •  Large Scale
  • With Pretreatment Skid

Read more about Reverse Osmosis Systems
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Sand Filters, Carbon Filters,
Water Softeners & Greensand Filters

Sand Filters, Carbon Filters, Water Softeners and Greensand Filters are all tank based water treatment technologies.

Please click to read more.

DI – Deionization Systems

Deionization Systems or Ion Exchange Systems remove contaminants by exchanging them with another ion.  In a softener it’s sodium that gets exchanged off the resin and or water constituents(H+ and OH-) in mixed resin exchanges.

Click to read more on Deionization Systems.

Portable/Rental Exchange Tanks – Regeneration off Site
Ion Exchange Systems – Technical Explanation
Ion Exchange Cartridges – Small Disposable Ion Exchange Cartridges

EDI-Electrodionization Water Systems

Perhaps the most recent widely accepted Water Purification process is EDI – Electrodionization.

EDI removes the remaining dissolved minerals (TDS) after Reverse Osmosis. EDI takes the place of the Ion Exchange step in many Electrodeionization System Designs.

Read more about the Process of Electrodeionization and EDI Water System Applications.

We utilize Electropure EDI systems manufactured by Snowpure.

– Pharmaceutical & Laboratory
Power Generation
– Semiconductor and Electronics

Iron Removal Filters/Systems

In New England iron is our most difficult water contaminant.
Also in New England iron is our most common contaminant.

Well waters contain Iron.
City water contains Iron corrosion of city mains.
Cooling Water contains iron from corrosion of piping in the cooling water system.

For well waters it’s best to get the iron before it goes from dissolved to suspended.
Greensand Filters
Water Softeners
For suspended Iron in the incoming water to a facility we use:
Sand and Multi-Media Filters
Once the Iron is in a facility to treat the process water we use:
Bag Filters
Cartridge Filters

Read more on Iron Removal Filters.

About Us:

Filters, Water & Instrumentation, Inc. (FWI) has been in business for 25 years, providing Filter Products, Water Purification Equipment and Instrumentation to industrial accounts in New England.

Serving the greater New England area, including: MA, NH, ME, VT, CT, RI, and NY.

Contact us:

Filters, Water &
Instrumentation, Inc.

15 Londonderry Road, Unit 11
Londonderry, NH 03053


Phone: 603-434-9577
Fax: 603-434-2832


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