Every water treatment system contains specific equipment, parts and components to achieve desired results. If you’re not sure what you need, just give us a call or send us an email. And if you need it, chances are that we have it.

Control Valves

Residential, commercial and industrial control valves can be fitted with various mechanical or electronic controllers to achieve virtually any result. These valves are available in the range from single tank units to multi-valve systems delivering over 1,000 gallons per minute of treated water. Call or email us any time to find out what’s available and in stock today.

Residential Control Valves (3/4″ to 1-1/2″)
Twin-Tank Valves (3/4″ to 1-1/2″)
Commercial & Industrial Valves (3/4″ to 3″)
AQ Matic (formerly AquaMatic) Diaphragm Valves

We stock AquaMatic diaphragm valves, including “Y” pattern valves in thermoplastic material, cast iron, cast brass and stainless steel. Certain of our systems use valve “nests” of these diaphragm valves, with or without a stagers, to program and control the valves, and controllers, which provide the ability to fine tune stager operation for almost every application. The AquaMatic series of diaphragm valves are alive and well, so please talk to us about the complete product offering. We have you covered at Duff.

Control Valve Parts

We’re the experts when it comes to all the spare parts you need. We also keep the largest stock of the most common parts, including:

  • Bypasses, yokes and meters
  • Seal and spacer kits
  • Piston assemblies
  • Brine valves
  • Injectors
  • Drain line flow controls
  • Special repair tools, pushers, stuffers
  • Drives and motors
  • Powerheads to replace or update timers
  • Timers and controls

Distribution Systems

We stock everything you need for distribution within the tank: Residential distributors, including distribution baskets, stacks and adapters, fine mesh distribution stacks; riser pipes; deburring tools; stack distributor assemblies; and other distribution assemblies.

Commercial distributors for fiberglass and steel tanks, including top-, side- and bottom mount valve distributors and steel tank distributors.

Mineral Tanks and Accessories

Structural, Clack, Enpress–we have it all.  We have the largest stock of residential, commercial and industrial mineral tanks.  poly tanks-2

Poly Glass tanks are the ideal pressure vessel for residential and light commercial water softener and filter applications. We stock these tanks in natural, blue, black and almond colors. These slim diameter tanks hold up to 49 gallons of water and offer unmatched strength and chemical resistance.

For commercial and industrial applications, composite pressure vessels offer fiberglass construction for outstanding performance and durability in harsh chemical environments. These tanks have capacities up to 2,500 gallons, with a variety of options (tank base; valve size, connection and location).

We also have the largest selection of specialty tanks, including FRP (available in either standard polyester or chemical-resistant vinylester construction), portable exchange tanks (available with noryl exchange heads/manifolds and rubber bump bands) and retention and contact tanks.

Inquire with us about tank accessories including tank jackets, in/out distribution heads, closures and adapters.

brineBrine Tank and Cabinet Components

Residential brine tanks come in various shapes, colors and sizes, including round and square, in blue, black or natural colors. Commercial brine tanks are generally black.

We are your go-to source for brine tank components like brine wells and caps, brine pick-ups, air checks, brine valves, polytubing, potassium permanganate valves and assemblies, Res-Up (and other resin cleaning) feeders, and every other imaginable item.

Retention Tanks, Chemical Solution Tanks and Feeders

Retention vessels are designed to provide optimal contact time for chemical treatment applications. Lightweight construction make these vessels easy to handle and install.

Demineralization/Deionization (DI) Components

DI TANKSDuff is your home for all your industrial and high-purity water needs.

Portable DI/demineralized water services are often a crucial part of our customers’ businesses. These movable tanks or cylinders run File_006from 0.5 to 45 cubic feet in capacity, and often incorporate different ion exchange resin types and tank sizes.

We carry a deep inventory of exchange tanks, heads and fittings, including in/out heads–both with and without fill ports, stainless steel bands, threaded connections, and complete distributor assemblies–and quick disconnect fittings. We also keep a vast inventory of mixed bed resin and other specialties.

If you have any questions about DI water, we’re the place to turn.

Plumbing Fittings & Tools

As a full-line plumbing supply house, Duff is also your go-to source for plumbing fittings, pipe, tubing, and valves. We stock copper tubing, copper sweat fittings,  copper press fittings and tools, pex fittings and pipe, in plastic and brass, SharkBite fittings, John Guest fittings–and any imaginable tool or plumbing supply.