Duplex Water Softeners

Duplex water softeners are available in a range of sizes, from 20 litres up to 250 litres making them ideal solutions for when moderate amounts of softened water is required on a 24/7 basis. Hard water contains magnesium and calcium ions, which are responsible for causing scale. This scale can cause pipes to clog, unsightly crusting and marks on faucets and showerheads, as well as cause appliances such as dishwashers, washing machines and boilers to have reduced effectiveness and lifespan.

Duplex water softeners are great solutions for large factories, agricultural applications, cooling towers and laundries where softened water is needed 24/7. Duplex softeners are actually two softener tanks working the exact same way as a simplex water softener. However, when one of the tanks needs to go into regeneration, the second tank takes over softening the water whilst the first goes through the regeneration process. When the second tank then requires regeneration, they switch again, and so on. This process is called Service and Standby and enables you to have a constant supply of softener water, rather than having “downtime” during the regeneration process.

All our water softener units are supplied with “PURERESIN Company” Softener Resin [WRA300]. We can also offer Purolite Softener Resin [C100E] – please enquire for prices.

Commercial Water Softeners

For those requiring larger volumes of softened water, we also offer commercial water softeners. With models ranging from 250 litres up to 750 litres, the commercial duplex water softeners are ideal for when you require constant, softened water at industrial quantities.

Regeneration Process

Water softeners work by removing magnesium and/or calcium ions from the water. It does this by swapping the calcium/magnesium ions with sodium ions in a process called ion exchange. Eventually the resin will require regeneration as the sodium ions are exhausted. Regeneration uses a saltwater solution from a brine tank to recharge the resin with sodium ions and remove the magnesium/calcium ions. The resin is also rinsed to remove any clogs or deposits and to remove any excess salt build-up from the regeneration process. Depending on the size of the water softener unit, the regeneration process can take anywhere between 70 minutes to a few hours. The only requirement from the user is to top up the brine tank with salt when needed.

Clack Valves

Our standard water softeners are fitted with 1″ or 1.25″ Clack Valves. Each Duplex system has either a single TT CI Valve or two CI Valves and interconnecting Motorised Alternating Valve.

Our commercial water softeners can also be fitted with 1.5″ and 2″ Clack Valves.

Service Parts

We provide a number of service parts and tools for maintaining Clack Valves, including:

  • Clack Valve Wrench
  • Clack 1″ Bypass Assembly
  • Clack Motorised Alternating Valve for 1.5″ and 2″
  • Clack 3/4″ Male BSP Adaptor Kit
  • Clack No Hardwater Bypass Valve
  • Clack Vertical 90o Adaptor Kit
  • Clack Stack Puller

If you wish to know more about this product please feel free to reach out using the contact form below:


Resin Volume x220 Litres30 Litres40 Litres50 Litres60 Litres
Twin Alternating (TT-DS) Part No.WF0835CITT-DSWF1035CITT-DSWF1044CITT-DSWF1054CITT-DSWF1252CITT-DS
Motorised Alternating Valve (MAV) Part No.WF0835CI-DSWF1035CI-DSWF1044CI-DSWF1054CI-DSWF1252CI-DS
Tank Size (inches) x28 x 3510 x 3510 x 4410 x 5412 x 52
Recommended Service Flow (m3/hr)
Volume Capacity between Regens @ 300 ppm (m3)
Brine Tank Volume (litres)859595140140
Salt Usage per Regen (kgs)
WS1 Injector ColourVioletWhiteWhiteWhiteBlue
WS1 Drain Line Flow Controller017022022027042
Approx. Footprint
D x W x H cms
50 x 74 x 13050 x 85 x 13050 x 85 x 15257 x 85 x 17762 x 92 x 172
Approx. Regen Duration (minutes)7075808080
  • Water softening units available between 20 litres and 750 litres.
  • Fitted with either a single TT CI Valve or two CI Valves and interconnecting Motorised Alternating Valve.
  • Duplex system makes softened water available 24/7 with no downtime during regeneration.
  • Increases the effectiveness and lifespan of appliances such as dishwashers, washing machines and boilers.
  • Prevents limescale build up on faucets, showerheads and inside pipework.

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